2018 | št.: 61/2 ISSN Tiskana izdaja / Print edition: 0016-7789 Spletna izdaja / Online edition: 1854-620X GEOLOGIJA 61/2 – 2018 GEOLOGIJA ISSN 0016-7789 http://www.geologija-revija.si/userfiles/image/BY.jpg Izdajatelj: Geološki zavod Slovenije, zanj direktor Miloš Bavec Publisher: Geological Survey of Slovenia, represented by Director Miloš Bavec Financirata Javna agencija za raziskovalno dejavnost Republike Slovenije in Geološki zavod Slovenije Financed by the Slovenian Research Agency and the Geological Survey of Slovenia Vsebina številke 61/2 je bila sprejeta na seji Uredniškega odbora, dne 17. 12. 2018. Manuscripts of the Volume 61/2 accepted by Editorial and Scientific Advisory Board on December 17, 2018. Glavna in odgovorna urednica / Editor-in-Chief: Mateja Gosar Tehnicna urednica / Technical Editor: Bernarda Bole Uredniški odbor / Editorial Board Dunja aljinovic haralD loBitzer Rudarsko-geološki naftni fakultet, Zagreb Geologische Bundesanstalt, Wien Maria joão Batista Miloš Miler National Laboratory of Energy and Geology, Lisbona Geološki zavod Slovenije, Ljubljana Miloš Bavec rinalDo nicolich Geološki zavod Slovenije, Ljubljana University of Trieste, Dip. di Ingegneria Civile, Italy Mihael Brencic siMon Pirc Naravoslovnotehniška fakulteta, Univerza v Ljubljani Naravoslovnotehniška fakulteta, Univerza v Ljubljani Giovanni B. carulli Mihael riBicic Dip. di Sci. Geol., Amb. e Marine, Università di Trieste Naravoslovnotehniška fakulteta, Univerza v Ljubljani Katica DroBne nina rMan Znanstvenoraziskovalni center SAZU, Ljubljana Geološki zavod Slovenije, Ljubljana jaDran FaGaneli Milan suDar Nacionalni inštitut za biologijo, MBP, Piran Faculty of Mining and Geology, Belgrade janos ha as sašo šturM Etvös Lorand University, Budapest Institut »Jožef Stefan«, Ljubljana BoGDan jurKovšeK DraGica turnšeK Geološki zavod Slovenije, Ljubljana Slovenska akademija znanosti in umetnosti, Ljubljana roMan Koch Miran veselic Institut für Paläontologie, Universität Erlangen-Nürnberg Fakulteta za gradbeništvo in geodezijo, Univerza v MarKo KoMac Ljubljani Poslovno svetovanje s.p., Ljubljana Naslov uredništva / Editorial Office: GEOLOGIJA Geološki zavod Slovenije / Geological Survey of Slovenia Dimiceva ulica 14, SI-1000 Ljubljana, Slovenija Tel.: +386 (01) 2809-700, Fax: +386 (01) 2809-753, e-mail: urednik@geologija-revija.si URL: http://www.geologija-revija.si/ GEOLOGIJA izhaja dvakrat letno. / GEOLOGIJA is published two times a year. 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Baze, v katerih je Geologija indeksirana / Indexation bases of Geologija: Scopus, Directory of Open Access Journals, GeoRef, Zoological Record, Geoscience e- Journals, EBSCOhost Cena / Price Posamezni izvod / Single Issue Letna narocnina / Annual Subscription Posameznik / Individual: 15 € Posameznik / Individual: 25 € Institucija / Institutional: 25 € Institucija / Institutional: 40 € Tisk / Printed by: GRAFIKA GRACER d.o.o. Slika na naslovni strani:. (foto: A. Kavcnik) Cover page: The Gaberke canyon. The torrent stream of Velunja has carved a deep canyon above the mining tunnels. 1st prize at the photo contest Geoscience for Society in the scope of this year's 5th Slovenian Geological Congress. (photo: A. Kavcnik) VSEBINA – CONTENTS Bavec, M. Manj sivine (uvodnik).......................................................................................................................... 131 Car, J. Geostructural mapping of karstified limestones............................................................................... Strukturno-geološko kartiranje zakraselih apnencev 133 Kercmar, J. Nahajališca zemeljskega plina na naftno-plinskem polju Petišovci ............................................. Natural gas reservoirs on the oil-gas field Petišovci 163 177 191 205 215 229 239 253 Porocila Kolar-Jurkovšek, T.: Porocilo o I. strokovnem simpoziju o rudniku Sitarjevec, Litija 20. 9. 2018 .. 267 Brencic, M.: Hidrogeološki kolokviji v obdobju od 2016 do 2018 ...................................................... 268 Novak, M. & Rman, N.: Porocilo o 5. slovenskem geološkem kongresu, Velenje 3. – 5. 10. 2018 ..... 270 Rman, N.: Short report on: Post-congress field trip of the 5th Slovenian Geological Congress, October 6th–8th 2018: Geology, hydrogeology and geothermy of NE Slovenia and N Croatia .. 274 Žvab Rožic, P.: Posvetovanje »Vloga in pomen geologije v formalnem izobraževanju«, 5. 12. 2019, Oddelek za geologijo NTF.................................................................................................................. 276 Navodila avtorjem ................................................................................................................................... 278 Instructions for authors .......................................................................................................................... 279 GEOLOGIJA 61/2, 131-132, Ljubljana 2018 © Author(s) 2018. CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.009 Manj sivine (uvodnik) Jasna, neposredna in merljiva dobrobit, ki jo ustvarjajo geoznanosti in predvsem koristi, ki jih ima in bi jih lahko imela od njih družba, so nam, bralcem Geologije, dobro znane. Ob vrhunskem razisko­vanju je vsaj enako pomembno ali še pomembnejše vracanje rezultatov družbi v obliki neposredno uporabnih rezultatov. Tega se zavedamo in v tej smeri tudi delujemo, kar je dokazala tudi izjemna raznolikost znanstvenih in strokovnih prispevkov na petem slovenskem geološkem kongresu, ki sta ga Slovensko geološko društvo in Geološki zavod Slovenije s partnerji organizirala med 3. in 5. oktobrom 2018 v Velenju. Vprašanje pa je, ali se tudi okolje oziroma družba, v kateri delujemo, v zadostni meri zaveda, da je znanje o lastnostih našega planeta temelj za sonaravni razvoj, da se brez temeljnega geološkega znanja ne bi mogli, ali se ne bi smeli izvesti nobeni vecji infrastrukturni, energetski in okoljski projekti? Se, pa ne dovolj. Zato smo si kot enega od kljucnih ciljev petega kongresa zastavili, da jasno povemo širšemu družbenemu okolju, naj vendar vec in bolje uporablja naše znanje. Med vrsto vrhunskih predavanj in posterjev smo tako na kongresni program uvrstili tudi okrog­lo mizo z uglednimi razpravljavci z naslovom: Je Slovenija pripravljena na uporabo geološkega zna­nja pri svojem razvoju? Cilj okrogle mize je bil odpreti razpravo o tem, ali sta zbiranje in dostopnost geoloških podatkov v Slovenji primerno urejeni. Ali so ti podatki sistematicno zbrani, interpretirani in razpoložljivi vsem, ki vstopajo v procese kakršnihkoli posegov v prostor. V kontekstu razprave o vlogi in pomenu geoznanosti za družbo smo povabili tudi plenarna predavatelja iz dveh najvecjih geoloških združenj v Evropi in vodilno svetovno povezovalko znanosti in strokovnega dela. Vsi trije so predava­nja posvetili povezovanju znanosti s strokovnim delom, pomenu in izjemnim koristim našega znanja za sodobno družbo. Spregovorili pa so o še eni, še kako pomembni temi, o geoetiki. Vecina geoznanstvenikov se tudi izven strogo strokovnega okolja trudi približati geoznanost našim deležnikom in graditi zavedanje o njenem pomenu. Odziv se izboljšuje in upam si trditi, da so casi za našo stroko dobri, in da se znamo vse bolje sporazumevati z uporabniki našega znanja. Crni casi za našo stroko so torej za nami. So, ampak še dlje za nami so ostali tudi zlati casi za geolo­gijo, ki so bili, ne nakljucno, tudi zlati casi za dr užbo in za njen ekonomski razvoj. Zato moramo vztra­jati pri povezovanju in prebujanju geološke stroke in prebudili bomo tudi družbo, da se bo ta zacela še bolj zavedati njenega pomena. Ce kje, se ravno v naši stroki zavedamo, da v naravi ni nic koncnega. Zavedamo se, da se vse spre­minja in zato bi bilo napacno razmišljati, da bi lahko z enim velikim dokoncnim korakom spremenili percepcijo naše stroke v okolju. Potrebna je množica malih korakov proti cilju. Z malimi koraki lažje obvladujemo in tudi usmerjamo spremembe na tej poti. In kaj nas na njej caka? Ob upoštevanju najno­vejših smernic stroke in znanosti je treba strniti vse znanje in izkušnje pri nikoli koncanem posoda­bljanju programa izobraževanja geologov. Z vsemi mocmi moramo podpreti prizadevanja naših kolegov za uvajanje geoloških vsebin v šolski sistem. Naši otroci nas morajo bolje razumeti kot naši sodobniki. Predvsem pa nas caka ureditev geološke zakonodaje, ki mora postaviti stroko in državo nazaj na ze­mljevid držav, ki svoj trajnostni razvoj temeljijo na odkrivanju in ne skrivanju dognanj o zgradbi in lastnostih svojega podpovršja. Brez tega ne bo šlo. Ob posodabljanju geološke zakonodaje ne smemo pozabiti na široko sodelovanje pri prizadevanjih inženirskega dela naše stroke, da si s kakovostnim de­lom in stalnim izobraževanjem zagotavlja svoje mesto na zahtevnih in visoko konkurencnih podrocjih svojega dela. Peti geološki kongres je pokazal enotnost stroke, da ribarjenja v kalnem in ustvarjanja sivin zaradi nedosegljivosti geoloških podatkov ne koristi nikomur. Potrebujemo urejenost in jasno dolocena sediš­ca na vlaku, ki potuje v eno smer, v smer urejenosti in dostopnosti sodobno interpretiranih geoloških podatkov. Trenutek je torej pravi. Nenazadnje o tem govori tudi udeležba visokih gostov na kongresu in za organizatorje presenetljivo pozitiven odziv raznovrstnih uglednih podjetij in drugih deležnikov, ki so pristopili k partnerstvu ali sponzorstvu kongresa. Tudi to je dokaz, da se dojemanje potrebe po sodelo­vanju z geološko stroko izboljšuje. Simbolicno ali ne, nakljucno ali ne, z velikim veseljem izpostavljam, da tokratna tiskana izdaja Geologije spet prihaja med nas v barvah, ki zamenjujejo sivino. Cestitam avtorjem, ki s kvalitetnimi prispevki hitro dvigujete raven naše stanovske znanstvene revije in cestitam uredništvu, ki s svojimi prizadevanji to uspešno podpira. dr. Miloš Bavec, direktor GeoZS GEOLOGIJA 61/2, 133-162, Ljubljana 2018 © Author(s) 2018. CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.010 Geostructural mapping of karstified limestones Strukturno-geološko kartiranje zakraselih apnencev Jože CAR Finžgarjeva 18, SI-5280 Idrija, Slovenija; e-mail: joze.car@siol.net Prejeto / Received 6. 7. 2018; Sprejeto / Accepted 24. 10. 2018; Objavljeno na spletu / Published online 20. 12. 2018 Key words: geostructural mapping of karstified limestones, plicative deformations, thrust– shear– deformations, fault induced deformations, structural framework, speleogenetic network, karst surface shaping Kljucne besede: strukturno-geološko kartiranje zakraselih apnencev, deformacije pri gubanju, obnarivne deformacije, prelomne in obprelomne deformacije apnencev, strukturna rešetka, speleogenetska mreža, oblikovanje kraškega površja Abstract The goal of the present paper is presentation of the structural mapping of the karstified limestones, and the relations between the surface and the underground karstification. When mapping on the large scale the frequency of the dip and strike must be increased. Possible intebeds of alien rock must be registered. Measurements of the dip make it possible to ascertain possible plicative deformations. Intercalations of non-carbonate rocks influence the underground water flow and affect the formation, shaping and location of the karst voids as well as the surface karst features. For the understanding of the karstification processes exhaustive collection of structural data, and recognition of broken, crushed and fractured zones within and parallel to fault zones, plus thrust– shear–zones are essential. As spatial organization and dimensions of the underground karst voids, as the surface karst shaping are guided by thrust parallel and fault induced deflection structures. All structural elements, which include tectonic elements as well as bedding planes, lithological changes, lithological partings, less permeable or impermeable interbeds, plus structural elements contribute to the structural framework. It directs both vertical percolation and horizontal streaming within the limestone and influence the frequency, size, spatial distribution, and shape of interconnected karst voids. The later form the speleogenetic network. Due to the permanent denudation the intersection of the Earth surface and the structural framework and speleogenetic network permanently moves downwards. New structural elements emerge while speleological structures change to less recognizable succession objects. The surface of the karst may be characterized as a dynamic, spatial, hydrogeological and speleological succession system permanently affected by the current tectonic activity. Izvlecek Pri struktur nem kartiranju zakraselih apnencev moramo povecati pogostnost mer jenja vpadov in slemenitve plasti in izrisati vse vkljucke drugih kamnin v apnencih. Meritve plasti nam omogocajo ugotoviti plikativne deformacije, vkljucki kamnin usmerjajo pretakanje vode in vplivajo na nastanek, oblikovanje in potek podzemskih prostorov in na oblikovanje kraškga površja. Pri kartiranju obnarivno in obtektonsko pretrtih apnencev, je za razumevanje procesov zakrasevanja, potrebno lociti zdrobljene porušene in razpoklinske cone. Velik vpliv na razpored in velikost podzemskih prostorov in površinsko oblikovanje kras imajo tudi litološke, obnarivne in prelomne hidrološke zadrževalno-zaporne strukture. Vsi strukturni elementi, med katere poleg tektonskih elementov štejemo tudi lezike, litološke spremembe, vložki drugih kamnin in zadrževalno-zaporne strukture gradijo strukturno rešetko. Ti vplivajo na nastanek speleogenetske mreže, ki zajema vse podzemske prostore. Zaradi denudacije se presek kraškega površja pomika navzdol po strukturni in speleogenetski mreži. Odpirajo se novi strukturni elementi, speleološki elementi pa postopno izginjajo in na površini ostajajo le bolj ali manj spoznavni nasledstveni objekti. Kraški teren lahko opredelimo kot dinamicen prostorsko hidrogeološki in speleološki-nasledstveni sistem, ki je pod stalnim vplivom aktualnih tektonskih premikanj. Introduction Physical karstology research has primarily been focussed upon “… speleogenesis, hydroge­ology, sedimentology, geochemistry, mineral­ogy, cave biology and unusual landforms. Only a smaller number of papers focus on karst sur­face landforms and among these only a few at­tempt organic and comprehensive studies of the entire assemblage of relief forms in a karst mor­pho-unit. In reality, it is evident that the surface landform complex in a karst morpho-unit has to be considered in its entirety and that only such an integrated approach to this complex entity may bring significant progress in understand­ing.” (Sauro, 2013, 5). There is no doubt that fun­damental knowledge about the surface forms stems from an understanding of the geological background. Geological investigation generally focusses upon the study of large limestone-covered areas, in lithostratigraphical as well as structural con­texts. Nevertheless, on the local level, studies of limestone terrains that contribute significantly to the understanding of the organization of the karst surface are relatively scarce (Car, 2015). The following text presents a general discus­sion about the results of detailed lithological, structural, and geomorphological mapping, sup­ported by examples of recent outcomes. The re­sults of the mapping make it easier to understand the determination of the relationships between the structure and various structural-lithological settings of karst surface phenomena, the inter­pretation of the areal location and distribution of surface karst phenomena, and interpretation of their sizes and shapes, as well as their inter-re­lationships (Car, 1986, 2001). Further considera­tions lead to deeper understanding of the dynam­ics of karst surface development, the links with the subsurface, and relationships to remnants of former speleological objects that are now ex­posed at the surface. Karst is a complex geological, hydrological, speleological, and geomorphic system. Con­sequently, mapping of karstified terrains is a challenging task. In order to ensure a reliable interpretation of the actual karst surface shap­ing a detailed knowledge of the local geological situation (lithology and structure, not forgetting details of the regional tectonic development) is vital. Knowledge of the local speleological situa­tion is necessary to help explain any denudation-al artefacts comprising the remains of previous cave objects that are important elements of the present karst surface (Car, 2015). Development of a methodology for mapping karstified limestones, and the most relevant outcomes These procedures for detailed structural mapping originate from the author’s long-term experience gained in the Idrija (Slovenia) mer­cury mine, where all of the mine workings were mapped at scales of 1: 500 or 1: 1000. Added to this experience was the insight provided by a longstanding interest in the karst. There was an inevitable curiosity to investigate whether the techniques applied in the mine could be applied to the mapping of karstified limestones. Hence, step by step, a methodology for structural map­ping of karstified limestone was developed, as synthesized the present paper. The approach desceibed for the structural mapping of karstified limestone evolved predom­inantly in the karst close to Idrja and the Karst of Notranjska (basin of the Ljubljanica river), in western and central Slovenia. Most of the infor­mation provided in the present text stems from these ter rains; nevertheless an identical approach has also tested and implemented successfully in several other areas of Slovenia. To the author’s knowledge there is no descrip­tion of a comparably detailed approach to the structural mapping of karstified limestones that is documented within the karstological litera­ture. The genetic relationships between karst phe­nomena and the thrust-front in the Idrija region were first recognized in 1974 (Car, 1974). Specif­ic geological and hydrogeological conditions ap­pear along the thrust margin, thus inducing the formation of vertical shafts beneath the dolomite block where it is thrust over limestone - sub-thrust karst. The “subthrast karst” phenomenon I first described (Car, 1974) under the term “cov­ered karst” (zakriti kras). It transpired that a profound knowledge of the structural-lithological setting, which can be re­vealed only by detailed geological mapping, is re­quired for a reliable interpretation of the surface to be produced. Further, a methodology for the detailed litho­logical and structural mapping, including regis­tration of all surface karst objects and phenom­ena, as well as of other outstanding geomorphic entities, has been evolving during the mapping of the wider fringes of Planinsko polje (Car, 1982). The outflow border of the Planinsko polje is lo­cated in a wide, shattered, area of the Idrija fault. Consequently, various carbonate rocks have un­dergone significant tectonic alteration. Three different intensities of tectonic change of the rock were distinguished by Car (1982): crushed zone, broken zone, and fissured zone, whereas the more general term fractured zone was used to label zones of tectonically injured rocks with­out implying more-precise detail. Placer (1982) described crushed zone characteristics in de­tail. The other two categories, together with the general term fractured rock, were introduced by the present author (Car, 1982). Later, the concept presented above was extended slightly (Car & Pišljar, 1993). The main fi nding of extensive, detailed, struc­tural, lithological and geomor phological mapping in the areas between Grcarevec, Unec, Postojna, Strmica/Planina, and the Banjšce plateau, Grgar basin, and the Crni Vrh–Zadlog plateau is the fact that different fractured zone properties may change from one pattern to another in horizontal as well as vertical directions (Car, 1986). The hy­drological conditions having remained constant, changes of the fractured zones in the horizontal direction result in the formation of different sur­face karst depressions and linear-but-sinuous elevations between them that are aligned paral­lel to the zones. Due to the steady denudational lowering of the terrain and changes in the frac­ture zones in a vertical direction different types of karst depressions may appear, guided by the same vertical structures during some longer time span (Car, 1986). On the basis of the statements above and the mapping of approximately 4000 solution dolines, 8 different doline types, occur­ring in a variety of lithological and structural situations have been distinguished (Car, 2001). The methodology of mapping limestone ter­rains has gradually been complemented by estab­lishing the dynamic and kinematic properties of the Postojna and Idrija areas. Such models per­mit a deeper insight into the formation of various types of karstic depressions and reveal the rela­tionships between the location of cave entranc­es and specific types of local faulting and other structures (Car & Šebela, 1997; Car & Zagoda, 2005). Specifics of the karst surface shaping and the hydrological conditions along the overthrust fronts of dolomite upon limestone have been studied in the Idrija area (Car, 1974; Zagoda, 2004; Car & Zagoda, 2005) and in the vicinity of Predjama (Car & Šebela, 2001). Structural mapping was carried out in the hinterland of the Lijak spring in the Vipava val­ley (Car & Gospodaric, 1988), at Kajža in the Avšcek valley (Janež & Car, 1990), at Možnica (Car & Janež, l992) and at the Divje jezero spring (Car, 1996). T he str uctural conditions of the karst hinterland of large springs at the foot of the Trno­vski gozd plateau and adjacent areas of elevated relief were discussed in 1997 (Janež et al., 1997). The mapping procedure that was developed on the surface of the limestone massifs has also been implemented successfully when mapping under­ground karst (Šebela & Car, 1991; Šebela, 1991). It has revealed a fair degree of inter-relationship between the location and shaping of the cave pas­sages, lithology, and structural elements distin­guishable underground. Positive correlation was established between the better expressed surface features, structural elements and the locations of certain types of cave passages. On the other hand, it is generally seen that direct inter-relationships between the surface-distinguishable structural elements and the location of cave tunnels is rel­atively weak (Šebela & Car, 1991; Šebela, 1991, 1992, 1994, 1998). Important roles played by bed­ding planes, zones of bedding-plane slip and any connecting fissures, generating an effective po­rosity during the early period of speleogenesis, have been identi fied (Car & Šebela, 1998). Mihevc (2001) discussed the complex processes of spele­ogenesis in the Divaca karst, and the great im­pact of the former epiphreatic underground karst upon the arrangement of the recent karst surface in terms of the detailed study of unroofed caves. Šušteršic (1998) studied a similar topic in the context of the completely phreatic, denuded, cave system at Logaški Ravnik. Alternating sets of physical properties related to fracture patterns within deflector fault zones impose a strong influence upon speleogenesis, producing effective hydrological barriers deep in the interior of the karst. Poorly permeable or impermeable fault-zones guide the general di­rection of groundwater flow and influence the arrangement of complex active cave systems. On the overlying karst surface, strings of collapse dolines of different ages commonly indicate their subjacent locations (Šušteršic et al., 2001; Šušteršic, 2006; Žvab Rožic, et al., 2015). So far, the published results of the detailed lithological and structural mapping mentioned above have been based on mapping the karstified limestone, mainly of Jurassic–Cretaceous age, at the scale of 1: 5000; partly in the Idrija region, on the border of the Trnovski gozd plateau, and partly in the area between Logatec, Postojna and Cerknica. On the regional scale, the tecton­ic structure of the areas of western Slovenia re­ferred to has been studied in depth (M lakar, 1969; Placer, 1973, 1981, 1999, 2008, 2015; Gospodaric, 1986; Poljak, 2007; Vrabec et al., 2009; Mlakar & Car, 2009; Jurkovšek, 2010). Local structur­al conditions in the limestone, which directly affect surface shaping and the arrangement of the hydrological background have been studied by Gams (1966), Car (1982), Habic (1984); Car & Gospodaric (1984, 1988); Janež & Car (1990), Janež et al. (1997) and Car & Šebela, (1997). Mapping karstified limestone areas The method of mapping limestone areas stems essentially from more-generally applied geolog­ical mapping procedures, upgraded by making more measurements of dip and strike, and in­cluding more abundant, exact, registration of the structural elements. In parallel, geomorphologi­cal examination of the characteristic karst ele­vations and depressions, and recording of other, possibly recent, geomorphic details must be per­formed (Car, 1982, 1986). All identified geologi­cal information and other karstological data are recorded. Annotation of base maps at scales of 1: 10000 and 1: 5000 (exceptionally, at larger scales) is carried out “on the spot”. During field work in limestone terrains two main problems may arise. On nearly completely bare limestone the “abundance” of exposed rock commonly threatens to obscure the distinction between relevant and irrelevant information, especially when mapping highly variable fissure systems. Of course, one should record as much information as the base maps allow. After the field work has been done, facing of the adjacent terrains reveals repetitive, important, structural trends, and changes in the fracture density. Else­ where, opposed or contrasting difficulties may arise. Due to the soil layer, such as covers arable land and extensive meadows, original bare rock exposures may have been covered, or even elim­inated intentionally, and original information is not accessible directly. In such cases, mapping of all available exposures is the only possible ap­proach. Information acquired from adjacent ar­eas, beyond the borders of the covered terrain, generally suffices as the basis for a reliable inter­polation and interpretation of the situation in the unexposed or poorly exposed area. Karstologists have identified a number of more or less characteristic geomorphic features on bare karst surfaces (Gams, 1973; Habic, 1986). Suitably dense (1 m × 1 m grid, presently avail­able) LIDAR-derived surface elevation data have facilitated efficient interpretation of the spatial distribution of solution dolines and other surface features of the same order of size (fig. 1, A1-the result of terrestrial mapping). Additionally, these data have facilitated a significantly more accu­rate interpretation of the geological conditions. If the recording is not based upon LIDAR-gener­ated data one must make use of pre-existing data Figs. 1. A and B: Interpretation of the geostructural mapping of the Magdalena gora near Postojna A1 - Areal distribution of (solution) dolines – the result of terrestrial mapping A2 - Outstanding elevations and general terrain lowerings B3 - Lithological and stratigraphical information, including the dip angles, plus records of fold axes and stronger faults B4 - Structural map of the terrain: dip angles and fold axe, faults and fractured zones plus terrain lowerings are superimposed on the rudimentary terrain shaping. The map reveals an important accordance with medium scale karst surface entities and general relief lowerings. 1. Light grey, bedded or unbedded organogenic limestone with transitions to organogenic breccia 2. Grey to light-grey, thinly bedded limestone with rudistacea shells sections. 3. Grey to dark-grey, bedded or unbedded, organogenic limestone with inclusions of organogenic breccia 4. Gradual change in lithology 5. Dip and strike of the strata 6. Tensional fissured system 7. Fault, and dip of the fault plane 8. Crushed zone, tectonic breccia 9. Broken zone and the dip 10. Very dense fissured zone and the dip 11. Dense and less closely laminated fissured zone and the dip 12. The anticlinale axis with the direction of setting 13. (Solution) doline. 14. (Solution) doline with close-to-perpendicular slopes 15. General terrain depression 16. Elevation with height code 17. Entrance to a cave or pothole A B Figs. 1. A and B (usually large-scale topographical maps). Espe­cially in forested areas most such basic infor­ mation is insufficiently detailed. At some stage, surface karst entities, and essential structural elements, must be recorded during the general mapping procedure. Solution dolines are ubiquitous and charac­teristic karst surface features (Ford & Williams, 2007). As was stated many years ago (Car, 2001), their spatial distribution, interrelationships, shape and depth are related intimately to the geo-structural setting; therefore it is self-evident that particular attention should be paid to them. With dolines it is intuitive to outline the planar form of their perimeters on the map, and to meas­ure the direction of the regolith-filled central part of the doline floor (the direction of the longer axis), which generally reveal trends of different fracture zones (Car, 2001). In the case of adjacent dolines the interconnections (relatively lowered surfaces in the contact areas) must be recorded, if they exist. In most cases it is desirable to sketch two approximately mutually perpendicular pro­files across the doline. These reveal fundamental types of slopes (catenae) and relationships to the geological succession and structure. At the same time, the doline depth should be estimated (Car, 2001). As well as solution dolines, other relevant karst features must also be recorded, especial­ly collapse dolines and ponors, is including cave and pothole entrances. If appropriate, local high points, linear depressions, fault-zone side walls and general terrain lowerings, plus other prom­inent closed depressions, may also be recorded (fig. 1, A2). Attention should be paid to the re­mains of various denuded, earlier, speleological objects, such as unroofed caves and phantoms of collapse dolines (Šušteršic, 2000), etc. “Unclear or equivocal” cases must be noted, ideally to be studied in greater detail later. Bedding and lithology Intra-stratal structural and textural pecu­liarities of limestone, which can be commonly studied only under a microscope, are particu­larly critical to gaining an understanding of the earliest stages of karstification. Much has been published about this topic all around the world. In Slovenia, only a few publications, directly in­fluencing the present paper, can be mentioned (Šušteršic, 1994b, 1999; Brencic, 1996; Knez, 1996; Lowe & Gunn, 1997; Car & Šebela, 1998). Stratification bedding and lithological chang­es in the limestone are of primary importance to the understanding of surface and underground karstification, on local and regional levels (K nez, 1996; Car & Šebela, 1998). Different lithologi­cal partings and bedding planes provide notable influences upon the general permeability of the limestone and the orientation and morphology of karst phenomena. Clearly, one must trace and re­cord various partings and lithological changes in the limestone during structural geological map­ping, as well as making numerous measurements of dip and strike. Stratification As with surface karstification the role of stratigraphical bedding (bedding planes) is im­portant for speleogenesis, i.e. the organization of cave passages was recognized and appreciated quite early (see literature in Knez, 1996). With respect to speleogenesis in the phreatic zone, master (leading) bedding planes (inception ho­rizons) are particularly important (Knez, 1996; Šušteršic, 1998; Mihevc, 2001). Stratification ( bedding) planes are usually high ly per meable and have a signi ficant in fluence upon the organization of karst channel patterns. For the purposes of karstological studies in lime­ stone Car (2001) distinguished: A: thinly bedded (from 1 to 10 cm); B: medium bedded (10 cm and Fig. 2. Interbeds of early-diagenetic dolomites within Lower-Createcous limestone, and position of Najdena jama close to northwestern border of Planinsko polje. Lithologically complex dolomite beds guided the general directions of groundwater flow. They guided the speleogenesis and spatial distribution of the Najdena jama passages (see text!). 1. Light grey to grey bedded organogenic limestone 2. Coarse to block grained limestone conglomerate 3. Bedded, bituminous, dark-grey limestone with interbeds of early-diagenetic dolomites 4. Erosional surface 5. Fault, and dip of the fault plane 6. Dip and strike of the strata 7. The Najdena jama ground plan 8. Larger collapse dolines Fig. 2. more); and C: unbedded (massive) limestones. To a great extent the thickness of the strata deter­ mines the mechan ical proper ties of the limestone; however, the spatial orientation of the layers is equally important. Both of these factors also affect the arrangement of the surface. Regard­less of the potential subjective feeling that both spatial elements either do not change or change only insignificantly, measuring the dip and strike wherever possible is indispensable. This is the only way to ensure a solid starting point that will help to determine the impact of the bedding planes upon the course of karstification and also to obtain an insight into the potential fold defor­mations, which might be expressed in the form of large and barely detectible open folds. Folded strata may influence the formation and the shap­ing of the surface significantly. Lithology In the presence of appropriate hydrological and climatic conditions changes in lithology help to direct underground water streaming, and also guide the shape and positioning of minute surface karst phenomena; in some cases the ar­eal position of larger karst depressions, such as solution dolines, can also be affected. Two types of lithological changes in limestone influence the development of surface kartstification and spe­leogenesis on local, possibly even regional, lev­els. The fi rst type are linked to the stratification and comprise less permeable or impermeable in­terbeds in the form of thin stratified or laminar bodies of clay-enriched limestones, marlstones or claystones. Specific lithological changes general­ly encompass extensive, possibly-ancient, ero­sional surfaces, and unconformities with paleo­sols accompanied by other paleokarstic features. Most such interbeds are of local importance. Exceptionally their influence extends to greater distances and they act as hydrological barriers, guiding the arrangement and direction of the system drains. Mineral composition of interbeds can also affect the chemical composition of the karst water and, consequently, enhance karstifi­cation processes (Pezdic et al., 1998). The other group of changes encompasses all other modifications anywhere in the limestone. It includes the presence of various, general­ly less-permeable, non-fractured biostromes, lumachelles, and calcirudites or limestone brec­cias with micritic or clayey cement within the other wise uniform limestone sequence. Com­monly they stand proud of the surrounding rocks. Un modi fied biostromes and lumachelles are basi­cally brittle. If cut by intense laminations they disintegrate into blocks and produce a relatively subdued surface topography (fig. 1, B3). Due to their faster rate of mechanical dis­integration, dolomite terrains set into broader limestone surroundings are relatively smooth with virtually no larger blocks protruding from the ground. In the case of early-diagenetic do­lomites the relatively flattened surfaces extend along strike, whereas late-diagenetic ones tend to be irregular. Considering that, compared to most limestones, the permeability of dolomites is relative low, the downward washing of insoluble weathering products is impeded. Consequently, the dolomite “oases” are covered by layers of soil or loam of different thicknesses. Interbeds of early-diagenetic dolomites can be of local or regional importance, depending upon their thickness and areal extents. From the hy­drological viewpoint they are less permeable and therefore they represent potential hydrological barriers within the limestone. They can guide the general directions of groundwater flow and influence the spatial distribution of speleological objects (fig. 2). Late-diagenetic dolomites play a similar role, and other late-diagenetic changes of local or regional dimensions can be imposed. Hydrologically and geomechanically, even lime­stones that are only partially dolomitized may behave quite differently from purer limestones. On the surface, dolomitic interbeds and beds of dolomitized limestone weather faster than do pure limestones, and thus influence the shaping of the landscape (Šušteršic, 1998, 2013). When poorly permeable or impermeable rocks lie at the base of, or on top of, the karsti­fied limestone they induce specific hydrological conditions at the contact. Distinctive karst phe­nomena, bound to the contact zones, and their in­terrelationships, can be deciphered only with the help of detailed mapping. Structural mapping Since the early days of karst studies the role of faulting has been appreciated as an important influence upon karstification and the develop­ment of a number of specific phenomena, both on the surface and in the underground. This applies in the Dinaric karst of Slovenia as well as in oth­er karst areas throughout the world. The most prolific authors are Cvijic (1924), Bahun (1969), Gams (1974, 2003), Car (1974, 1982), Gospodaric (1976), Habic (1982, 1986), Šebela (1991, 1994), Car & Šebela (1997, 2001), Calic, (2009). Earlier researchers took faults into account mainly as a general phenomenon, considered simply as indi­vidual discontinuities in the rock, or as undiffer­entiated fracture zones. Such an approach (Plac­ er, 1972; Šebela & Car, 1991; Šebela, 1992, 1998) is perhaps adequate for the study of regional situations on the karst surface and in the under­ground karst. Nevertheless, it is inadequate for a full understanding of individual local relation­ships. Only a detailed consideration of different degrees of fracturing (Car, 1982, 2001; Bauer et al., 2016) can yield sufficient information to en­able interpretations of the dimensions and shap­ing of particular phenomena, their dependence upon structural controls (especially the degree of fracturing) and the history of their genesis. Thus far, it is clear from the literature that, when interpreting the development of karst phe­nomena, faulting (in its widest sense) has been considered seriously, whereas relationships due to fold-related deformations have been studied more rarely (Davies, 1960; Aubert, 1966; Cucchi, et al., 1976; Car & Zagoda, 2005). Overthrusting, which also imposes special conditions for the karstification of limestone and impacts signifi­cantly upon the formation of surface karst, has been tackled only in exceptional cases (Car, 1974, 1982, 2001; Herak, 1986; Car & Šebela, 2001; Za­goda, 2004). Deformation along folds overthrusts and a variety of faults in limestone does not differ es­sentially from the general pattern of deformation related to plicative and disjunctive tectonic pro­cesses (T wiss & Moores, 1992; Woodcock & Schu­bert, 1994). Nevertheless, common deviations from the theoretical geometrical distribution of structural elements are not negligible. Predom­inantly they can be explained by changes in li­thology along the fault zones, by varying lengths of slips along individual faults, or by movement and changing related to multi-stage fracturing along tectonized zones. When describing and in­terpreting the actual situation observed on the terrain, it is necessary to take into account the impact of all the stages of tectonic movement that have so far been recognized (Gospodaric, 1976; Habic, 1982; Šebela, 1998; Placer, 2008, 2015). Folds and related deformatios Initial folds (i.e. structures imposed by the effects of early compression before the develop­ment of any subsequent overthrust units) can encompass extensive structural blocks that were created during the pre-thrusting period (Mlakar, 1969; Placer, 1973; Car, 2010). At the time of thrusting, less-pronounced folded deformations with gently inclined limbs form within the under-thrust block, whereas deformations are far more pronounced in the overthrust blocks. Particular­ly well-marked folds are formed parallel to the thrust fronts (Car & Gospodaric, 1988). Tightly folded strata and minor folds are observed pre­dominantly along strike-slips and normal faults (Twiss & Moores, 1992). Their impact upon karst morphology and the resultant karst objects can be both important and specific (Davies, 1960; Aubert, 1966; Cucchi, et al., 1976; Car & Zagoda, 2005). Zones of bedding-plane slip and any con­necting fissures are characteristic features (Car & Šebela, 1998). Generally, major regional folds are not readi­ly recognizable directly in limestone successions. Nevertheless, such folds may be revealed by tak­ing abundant measurements of the dip and strike (fig. 1 B3). Fold deformations and their – possibly strong – impact upon the geomorphic and karstic shaping of the limestone surface are easier to detect at locations where they have not suffered secondary distortion by later tectonic effects. Fissure systems with a fan-like distribution of more or less well-pronounced tension cracks in anticlinal structures, and pressure fractures in synclinal folds, which are generally sub-parallel to their axial planes, are of crucial importance to karst-surface shaping (Aubert, 1966; Cucchi, et al., 1976; Car & Zagoda, 2005), (figs. 1 B3 and B4). Thrust-shear-zone karst Fracture deformations related to compression, and with dip angles less than 45°, are general­ly termed thrust structures. Dip angles of thrust planes commonly vary between 15° and 35°, yet some may be closer to horizontal (Mlakar, 1969; Placer, 1973; Herak, 1977, 1986, Twiss & Moor­es, 1992). In most cases, more or less distinctive, secondary, thrust planes of various dimensions are observed within the over-thrust and un­der-thrust blocks (fig. 3, A1, A2). Dependent upon the local lithologies and the mechanical properties of the rocks that are in contact along the thrust planes, and also upon the energy released during thrusting, complicat­ed zones of thrust-shear-zone karst can appear. In consequence these zones are sub-horizontal and more or less parallel to the main thrust plane (fig. 3, A1, A2). In cases of the thrust contact of two mechanically different rocks, for instance do­lomite and limestone, the thrust-shear-zones are well expressed, and readily identified, whereas some contacts between two limestone blocks re­main hardly visible and thus barely recognizable. Crushed, broken and fissured rocks, similar to the tectonically fractured zones (Car, 1982), also appear along thrust planes. They develop in the under-thrust as well as in the over-thrust blocks. Thrust-generated crushed zones consist of cataclastic rocks, possibly secondar ily re-ce­mented to various degrees. Their thickness var­ies widely. Generally they are significantly more extensive in over-thrust limestone blocks than Fig. 3. Parallel to thrust structural and karst features. A Section of parallel-to-thrust generated fractu red zone. Being far less per meable than the adjacent intact rock they fu nction as hydrological barriers. It resulted in the formation of reproduced dolines (A-a) and covered karst (A-b). Succession objects appear on the thrust border area (A-c and A-d). Explanation in the text. B Position of the thrust–shear–plane between the Lower-Cretaceous limestone and Upper-Triassic dolomite at Rupe (by Idrija). Delineated are broken to crushed zones. 1. Grey, thinly bedded, Norian –Rhaetian dolomite (Hauptdolomit) fractured close to the thrust plane 2. Bedded, bituminous, dark-grey, bituminous, bedded Lower-Creataceous limestone fractured in the thrust plane vicinity 3. Clayey weathering products 4. Crushed zone in dolomite (overthrusted block); clay-rich tectonic rock-flour and breccia 5. Broken to crushed zone in limestone; chaotically arranged limestone blocks 6. Broken zones 7. Fissured zone 8. Groundplane of the crushed to broken zone in the thrust–shear–zone vicinity 9. Dip and strike of the fault plane 10. Thrust border and dip of the thrust plane 11. Secondary, more or less distinctive, thrust planes of different dimensions within the over-thrusted and under-thrusted blocks 12. A section of the border between thrust–shear zone and fractured rocks in the base (A). 13. A groundplane of the border between thrust–shear zone and fractured rocks in the base(B). 14. Dip and strike of the strata 15. Solution doline and the direction of the central part dip 16. Collapse doline 17. Covered karst – a vertical shaft generated beneath the over-thrusted dolomite 18. The over-thrusted block 19. The under-thrusted block Fig. 4. Characteristically chaotic arranged limesto­ne boulders and cobbles in the broken zone. a. Close to thrust-plane broken zone at Kodrov rovt near Idrija. b. Close to thrust-plane broken zone at Za Pšenkom near Idrija. in the under-thrust blocks (fig. 3, A1, A2). In the latter case compact tectonic breccias just a few metres thick appear. As a rule they are cemented by clay-rich tectonic rock-flour. Eventually, they become far less permeable than the adjacent in­tact rock and they function as hydrological bar­riers. In cases where such zones are dissected by younger faults, specific hydrological conditions develop, bringing about the formation of thrust­ shear-zone karst (fig. 3A). Thrust-shear-zones can develop to a wide va­riety of thicknesses, depending upon the general conditions at the time of thrusting. Most of them are several tens of metres thick; in the Idrija re­gion this might reach 100 or more metres. In the broken zones more-brittle limestones are disinte­grated into boulders and cobbles (block tectonites), (fig. 4 a, b), with the largest clasts several tens of metres in diameter. Primary bedding and dip can be preserved in the larger blocks, but such blocks were rotated, and the apparent dip differs from the true dip in the adjacent undeformed rocks. Thrust-shear-zones comprise rock that is traversed by numerous, closely spaced, less well-expressed thrust planes. Generally they are cut by sets of connecting fault planes that may penetrate far into the under-thrust and over-thrust blocks (fig. 3A). As distance from the main thrust plane increases, related deformations be­come scarcer and less extensive in both blocks. The previously discussed zones of bed-ding-plane slip (Car & Šebela, 1998) have a genet­ic connection with the thrust-plane-parallel slip zones. Bedding-plane slip zones appear within susceptible strata, approximately parallel to the main thrust plane or splaying from it at shallow angles. Their degree of expression and frequency depend upon the position of the affected stratum within the over-thrust or under-thrust blocks. Bedding-plane slip structures might have an im­portant role in speleogenesis, as they also do in surface shaping (Car, 1974, 1982; Knez, 1996; Car & Šebela, 1998, 2001; Mihevc, 2001). Thrust zones have been researched only poor­ly in the structural-karstological context. Thus far, the existing studies have revealed that zones of minor or severe shearing can play an impor­tant role in karst surface shaping (Car, 1974, 1982, 2001; Car & Gospodaric, 1984; Herak, 1986; Car & Šebela, 2001; Zagoda, 2004; Calic, 2009). Fault-related deformations In Slovenian literature the concepts of fissure and fault are defined only with a short general tag (Pavšic, 2006, 225, 236). Thus, it is necessary to reference foreign literature (Twiss & Moores, 1992). The distinction between fissures and faults is necessarily consensual because, in Nature, the transition from one to the other is continuous. By definition, fissures are mechanical discontinu­ities in the rocks where cracking has occurred. Small displacements may have occurred, per­pendicular to the fissure surfaces, or along them; they might, however, be completely absent. For the reasons mentioned above they do not affect the over-riding tectonic grain of the territory. In practice this means that the strike remains es­sentially continuous, and the dip doesn’t change. W here the strati fication has been displaced along mechanical discontinuities and the dip and strike angles are at least partially changed, mi­nor faulting must be suspected. For the purposes of karst-surface studies it is perfectly reasona­ble to consider rock discontinuities that can be traced for at least some tens of metres as faults. All the rest, i.e. the shorter discontinuities, are fissures (joints). According to the nature of the prevailing stress field, normal and reverse faults occur, as well as strike-slips. As mentioned above in the context of thrust zones, sub-horizontal deforma­ tions appear along reverse faults. With normal faults, tension fissures and fault zones of ten­sional character develop, whereas closed fissures are characteristic of compression zones. Internal structures differ between the two types of fault zone. To a great extent the different internal structures influence the general geomorphic sit­uation, the course of weathering, and the extent of karstification along the zones. Therefore it is important to scrutinize whether the fault zone is of compressional or tensional character. Initially Gladkov (1967) and Placer (1982) differentiated an internal zone and an external zone. Based on a case study in the Idrija Mine he (Placer, 1982) progressed the then knowledge about the structure and composition of the re­spective zones in dolomitic rocks. In limestone the internal structure of strike-slip faults is generally well-defined and readily observable (fig. 5a). At their outer margins they are delimited by boundary fault planes, where­as shear-planes mainly occur within the zones themselves (Placer, 1982) (fig. 5a, present text). The internal zones are filled with a variety of cataclastic rock material. Usually they comprise different-sized rock lenses mutually separated by internal fault planes. There are normally two external zones. They are built up differently ac­cording to the way the rock has fractured. As is to be expected, their thicknesses are also varia­ble. In some cases an outer zone is developed just on one side. On the other side only a zone of weak, parallel, fissuring is observable (fig. 5a, right). Generally the external zones pass gradually into unaffected rock (figs. 5, a, b) or into an adjacent fault zone. Only exceptionally they might be de­limited from the outside by shorter fault planes. The width of the fault zones depends upon the properties of the rocks that they cut and the ex­tent of the strike-slip movement. Tectonically affected rocks within fault zones are generally termed fractured rocks. As in thrust zones, crushed, broken and fissured zones are identified, depending upon the severity of fracturing (Car, 1982, 1986, 2001) (fig. 5b, present text). In the case of an idealized fault zone the crushed zone passes longitudinally into the bro­ken zone, and then into the narrow but closely laminated fissured zone, beyond where it either vanishes or reverts to a wide or narrow crushed zone (fig. 5b). Similar transitions are also pos­sible laterally across the fault zone, except that the fractured zones are significantly narrower (fig. 5a). Sequences of the different broken zones along stronger and longer faults can change re­peatedly across relatively short distances, ac­cording to local conditions. Some systems of fis­sures can also remain isolated, without passing into adjacent fractured zones. These represent the initial state in the formation of a fault zone. Given the general hydrological conditions, throughput of drainage along the fault zones changes in horizontal and vertical directions in parallel with the alternating properties of the fractured zones (Car, 1986) (fig. 6, present text). For this reason different surface karst phenom­ena can arise along just one single fault (Car, 2001). It transpires that a general knowledge of fault lines is insufficient. Instead, the degree of Fig. 5. Drawings a and b: Characteristics of fault zones. a. Drawing of two characteristic horizontal sections of the faults with the fault zones, main fault planes and characteristic arrangement of the fractured zones. b. Ground plane and section of a fault; indicated are changes of the fractured zones along the fault direction 1. Section of tectonically fractured rocks 2. Bedded limestone 3. Tectonic silt 4. Tectonic breccia 5. Broken zone 6. Dense fissured zone 7. Infrequently fissured zone 8. Fault 9. Direction of a block displacement 10. Transect A-B (drawing b) prepustno obmocje permeable zone neprepustno obmocje unpermeable zone prepustno obmocje permeable zone zunanja prelomna cona outside fault zone neprepustno obmocje unpermeable zone 1 2 3 4 5 6 7 8 Ni v merilu! Not to scale! zunanja prelomna cona outside fault zone notranja prelomna conainternally fault zone Fig. 6. Changes of the rock fracturation in the fault zone, in the vertical and horizontal direction. 1. Bedded limestone 2. Intersection of a fault-plane 3. Tectonic silt 4. Tectonic breccia fracturation of the rock must be sub-divided and recorded in detail, with special regard to rec­ ognizing and recording specific details of the crushed, broken and fissured zones (figs 5a, b). Crushed zones Placer (1982) investigated the structure of crushed zones, specifically in dolomitic rocks. He noted that the inter nal zone can be fi lled with tectonic clay ( fault gouge), mylonitic (cataclas­tic) rock-flour, mylonitic (cataclastic) silt, tec­ 5. Broken zone 6. Dense fissured zone 7. Infrequently fissured zone 8. Individual limestone blocks within the broken zone tonic breccia (fault breccia), and also “floating” blocks of rock of different sizes. On the basis of general estimates Bauer et al. (2016, 1152-1153) ranged the degree of tectonic fracturing of car­bonate rocks into 4 classes: weakly fractured rock, moderately fractured rock, intensely frac­tured rock, and very intensely fractured rock. They (Bauer et al., 2016) noted that the zones in question are filled with four types of cataclas­tic breccias that can range from highly permea­ble to impermeable. The two aspects of faults in limestones are generally better defined than in dolomites, and the inner zones are more simply built up (Car, 1982). Individual mechanical prop­erties of the infi lling material vary from case to case, but they change within a smaller range. The relatively thin tectonic clay coating and more- or less-well-cemented zones of tectonic silt and rock-flour are restricted predominantly to the in­ner fault-zone (Placer, 1982; Car, 1982; Bauer et al., 2016) (figs. 6 and 7, present text). In most cases tectonic breccias of different grain-size prevail (fig. 7). Properties of the crushed rocks within the ‘left’ and ‘right’ external fault zones pass grad­ ually from one to the other, in either direction; they appear in the form of differently-sized lenses separated by minor, internal, fractures (fig. 5a). Depending upon the petrology of the parent rocks and the physico-chemical conditions during and after formation, the crushed rocks are more or less indurated, with a predominantly reddish, clayey, cement (fig. 7). As well as the thickness­es of the crushed zones themselves varying, the dimensions of clasts of different crushed rocks within the zones (figs. 5 and 6) also vary. Locally, in the more-extensive crushed zones and in frac­ture inflection zones, plastic deformation occurs, leading to the development of folded cataclastic rocks. In cases where the cataclastic rocks of the in­ternal fault-zones are well cemented, especially within the pressure zones of strike-slip faults, they may protrude at the surface as long, narrow, crests. Where cementation is weak or otherwise poorly developed, the surface is marked by elon­gated, trench-like depressions (bogazes) (fig. 5b). Underground in the karst, primarily crushed, subsequently well-cemented rocks within the internal zones of strike-slip faults function as impermeable, or weakly permeable, hydrological bar riers. Broken zones The fundamental characteristic of broken zones in limestone sequences is the disintegra­tion of the intact bedrock into angular blocks of various sizes that may be more or less rotat­ed. Generally the original bedding becomes no longer detectible (Car, 1982) or can barely be de­duced (fig. 8). The size of blocks ranges between comminuted rock debris, held within a matrix of finely ground rock flour, and large cobbles, depending upon the lithological and sedimentological characteris­tics of the original limestone and the stress con­ditions. Broken zone thickness varies within a Fig. 7. Tectonic breccia cemented with terra rossa. Crushed zone of the Laze fault internal zone (Laze at Planinsko polje). broad range, possibly even reaching several tens of metres. Within the tensional stress-field link­ing broken zones between two strike-slip faults they can exceed several tens of metres or even more. Mostly they are developed on both sides of the inner fault zones, filled with broken rocks. Broken zones occur commonly on the external sides of fault zones. With less well-defi ned faults, they appear as lateral transitions on one or both sides of the internal fault zones. In many cases they are developed within the continuation of the crushed zones. However, they may also appear as isolated broken zones (figs. 5 a, b; fig. 6). Fissured zones Fissures (= joints; Car, 1982) are the most common mechanical deformations of limestones, but they are the most difficult to deal with us­ing standard geological mapping techniques. Fissures of various trends are commonly inter­woven. They impose a grid-like structure, and they can influence the form of the surface terrain strongly (figs. 9 and 10). The terminology of joints is complex and as yet it has not been unified (Twiss & Moores, 1992). Researchers must adapt appropriate terminolog y to match the actual field conditions. Most commonly joints are classified according to their dominant mode of genesis (dy­ namic-kinematic classification) and according to their spatial geometry. A number of faults of different intensity, ac­companied by swarms of secondary fissure sys­tems, cut through western Slovenia in a north­west–southeast direction (the Dinaric trend). Related to the fault strike direction, shear joints may appear more or less parallel to the north­west–southeast master faults. Conjugate joints on the Dinaric trend are normally absent. How­ever, if they do occur it is hard to detect them due to the extreme fracturing of the parent rock. Depending upon the degree of stratification and lithological variations, fissure directions may readily adapt and change their direction, thus curving according to micro-local conditions. Ac­cording to the present author’s field experience, the maximum angle of deviation from the master direction varies up to 35°. If observed deviation angles exceed this value the fissures in question belong to a different fault system. A number of minor, tensional, accommodation faults may ap­pear between two better-expressed faults. In most cases they form wide swarms of tension joints (longitudinal splitting), in the north–south direction, mainly with some degree of sinistral strike-slip. Adjacent to the two major faults the fissures are commonly contorted due to the pri­marily dextral strike-slip of individual blocks. Closed pressure-joints with small horizontal/ longitudinal displacements of blocks, possibly with a minor vertical component, can appear along strike-slip faults. Tension (relaxation) con­ditions give rise to joints with small horizontal displacements, and minor differential lowering of blocks between individual joints. In the context of individual swar ms of fissures within any specific fissured zone (compression­al or tensional) the types of fissures mentioned above can join into strings, and subsequently into clusters. They may be several tens or several hun­dred metres in length. If the fractures belong to differently directed fault-sets they may combine or intersect at different angles. Such dissected areas are designated as fissure zones (Twiss & Moores, 1992). Most of them are clearly delimited laterally. They either pass over into areas of mac­roscopically unfractured rock or they are delim­ited by short, poorly expressed fault planes. Lon­gitudinally they may pass into a more-fractured, crushed, zone or gradually become less numerous and eventually vanish (figs. 5a, b and 6). To help understand the course of karstification and the formation of karst phenomena at the local level, identification of fissured zones is sufficient. Distinguishing individual swarms of joint-fis­sures within the fissured zones is less important for the interpretation and understanding of karst surface shaping. However, because the degree of jointing influences the intensity of karstification and the nature of terrain shaping, the density of jointing within crushed zones is virtually cru­cial. Depending upon the type of problem to be solved and the accuracy required, in some cases it becomes desirable to subdivide fissured zones into rare, dense, and very dense categories (fig. 9 and 10). There are no clear-cut and widely useful criteria for helping to distinguish joint density and specific details of fracturing with certainty. Simply counting the fissures in a particular area does not produce useful results. Only compara­tive estimates of fracture density are reliable. Within each individual fracture cluster the joint density may change signi ficantly across relatively small distances. One must also consider the lith­ological and sedimentological changes of rocks, which can bring about insurmountable compli­cations. So far, it is best to estimate the relative density on the basis of a comparison of adjacent fissured zones. Bauer and colleagues (2016) came to similar conclusions. On the basis of subjective estimates, they have suggested “fracture class 1 (FC1) and fracture class 2 (FC2)”. In general these correspond to the present author’s classification of fi ssured zones (Car, 1982). If fissured systems of different intensities are mutually interrelat­ed in either a longitudinal or a lateral way they can readily be distinguished on the spot by sim­ply assessing the density of fracturing within the zones. Extremely closely fissured systems consist of dense, short, fractures of decimetre to metre lengths that are approximately mutually paral­lel. Fractures that are several metres long are rare in this context (fig. 9). Fig. 9. Dense fissured zone (Suha grapa by Idrija). Extremely dense fissure systems commonly represent inter mediate, longitudinal, continua­tions of crushed zones. Alternatively, they may extend in narrow stripes parallel to them. Tran­sitions are generally continuous and gradual (fig. 5b). In such cases, the logical boundary between the fissured and the crushed zones can be set where stratification becomes observable (fig. 10). If the rock is not stratified attention must be paid to sedimentological and other early, structural, phenomena. Detailed mapping always confirms that one fracture direction is dominant. Obvious­ly this one must be recorded. Deflecting structures (temporary hydrological barriers) Temporary hydrological barriers are impor­tant structural elements in the karst. According to their relationships to various structural ele­ments one may distinguish lithologically condi­tioned hydrological barriers, thrust-parallel hy­drological barriers, and deflector faults (Šušteršic et al., 2001; Šušteršic, 2006). Bahun (1979) point­ed out the importance of the guiding role of types of rupture that induce essential changes in karst water-table levels. Unfortunately, he did not characterize such ruptures in more-general geological terms. Bauer et al. (2016) tackled the hydrological role of faults with poorly permeable cataclastic cores. Deflecting structures are not only paramount factors in determining the ar­rangement of the karst surface, but they have an important, in many cases even decisive, influence on the underground hydrological situation, and on the course of speleogenesis. They can be de­tected by more-precise, conventional, geological, mapping of both the karst surface and of cave systems. In general they do not present absolute hydrological barriers. Rather than being abso­lutely impermeable “dam-barrages”, they man­ifest as less permeable tracts within the other­wise highly permeable limestone mass. At times of lower discharge they (normally) do not im­ pede underground flow at all. Under conditions of higher discharge, however, their transmission capability is restricted and they limit the maxi­ mum th rough-flow to a speci fic volume (Šušteršic et al., 2001; Bauer et al., 2016). Their hydrological role is not constant and varies depending upon the internal structures of the barriers, as well as upon the amount of water being transmitted. During times of extreme inflow they deflect any excess water flow and direct the surplus along more-permeable fissured zones and oth­er high-conductivity structures, predominant­ly along broken zones, fissured zones, and bed-ding-plane partings. Such a role of the deflector structures induces conditions that are appro­priate for the development of cave sub-systems parallel to the master fault (Šušteršic et al., 2001; Žvab Rožic, Car & Rožic, 2015). Lithological barrier strata Less permeable intercalations within high­ly permeable limestones behave as lithological, hydrological, barriers (fig. 2). In most cases they are intra-formational lenses of early-diagenet­ic or late-diagenetic dolomite, or beds of marly limestone. Less common are disconformity or unconformity planes characterized by crusts of palaeo-regolith (palaeosols) or basal carbonate sand-conglomerate bedrock. Each of these rocks can exert an effective influence upon the un­derground karst and act as water-tight or poor­ly-permeable lithological, mineralogical barriers. Due to the effects of diagenetic processes most of the dolomite beds in otherwise limestone-dom­inated lithological sequences are not completely uniform (Zogovic, 1966). Within early-diagenet­ic dolomite developments, lenses of limestone, dolomitized limestone, and transitional litholo­gies can appear where late-stage dissolution of primary gypsum creates a honeycomb-like tex­ture within early-diagenetic dolomite intervals. Similar rocks may also appear in late-diagenetic dolomite. Rocks of the lithologies listed above, occurring on the margins of dolomite lenses are significantly more permeable than the pure do­lomite or “standard limestone” occurring in the wider area around the lenses. This is why the lithologically heterogeneous dolomite lenses – so called because the dolomite predominates – play such a markedly dual role hydrologically. On the one hand “pure” dolomite blocks interfere with and deflect the water flow. However, the highly permeable intercalations within dolomite lenses enhance the through-flow and guide the outflow. In this way cave channels can form along and within dolomite lenses (Šušteršic, 1994b; fig. 2, present text). An example of such a composite lithological sequence and its influence upon the local karst phenomena, is the approximately 30 m-thick dolo­mite layer within the Early Cretaceous limestone at the northeastern margin of the Planinsko polje (Car, 1982; Gospodaric, 1982; Šušteršic, 1982; fig. 2, present text). The dolomite surface is relative­ly smooth and free of karren. Solution dolines are less abundant (Šušteršic, 1987) and less pro­nounced than on the limestone in the neighbour­ing terrain. Most of the presently known passages in Najdena jama have been formed on its upper and lower contacts, and partly within this lens (Šušteršic, 1994b). Cave passages developed even in the more transmissive layers within the dolo­ mite lenses (Gospodaric, 1982; Šušteršic, 2002). The main barrier is the transition zone be­tween the syn-sedimentary erosion surface over­lain by a coarse, basal, partly dolomitic conglom­erate with clayey cement (Gospodaric, 1982). Thrust-parallel hydrological barriers The process of karsti fication and its inter me­diate geomor phic effects upon the impermeable or poorly permeable, sub-horizontal, crushed zones along thrust planes have brought about the for mation of a specific type of limestone karst along the thrust front. Each combination of underthrust and overthrust rocks brings about particular hydrological conditions. They induce a specific development of karstification and specific shaping of the karst surface. So far such cases have been examined only along the zone where Norian–Rhaetian dolomite (Cek­ovnik thrust slice - Mlakar, 1969) is thrust over limestones of the Koševnik thrust slice (Mlakar, 1969) in west-central Slovenia (the Idrija re­gion and in the wider area of Planinsko and Cerkniško poljes) (Car, 1974; Car, 2001; Car & Šebela, 2001; Zagoda, 2004; fig. 3, present text). Any anticipated comparable effects of such a style of karstification on other locations of sim­ilar type have not yet been studied in adequate detail. Within the range of the thrust contact be­tween two limestone blocks the crushed zones in both the overthrust and the underthrust blocks are characterized by the occurrence of compact, tectonic, re-cemented limestone breccias, which assume the appearance of solid limestone. Gener­ally a barely noticeable thrust plane, which may readily be overlooked, is present in the middle of the brecciated mass. Compact breccias are signif­icantly less permeable than the adjacent unbrec­ciated rock, and generally they function as bar­riers. Meteoric water can penetrate the breccia layers only via various fault structures and joints, bringing about the formation of corrosional ex­cavations, overhangs and minor caves. Details of how thrust planes between limestone-upon-lime­stone appear underground are yet to be studied. Comparable contacts between limestones and mechanically weaker rocks (figs. 3 A and B) are essentially better expressed (Car, 1974, 1982; Herak, 1986; Mihevc, 1994; Car & Zagoda, 2005; Mlakar & Car, 2009). Extensive planation sur­faces appear on the overthrust contacts of Late Triassic, Norian–Rhaetian, dolomite upon lime­stones of various ages (Car, 1982; Car & Šebela, 2001; Zagoda, 2004). Thick crushed zones within the overthrust dolomite are permeable only along younger, post-thrusting faults cutting through the zone (fig. 3 A). Numerous poorly developed dolines (Car, 1974; Car, 2001; Zagoda, 2004) and proto-dolines (Sauro, 1995) appear next to the faults. Generally a crushed zone is absent in the underthrust limestone block. Along a narrow band in the immediate vicinity of the thrust con­tact the surface topography is relative flat and subdued, covered with dolomite weathering de­bris that extends into the thrust-parallel broken zone (figs. 3 A,B and 4 a and b). At a greater dis­tance from the thrust front the land surface takes on a characteristically karstic appearance, with solution dolines and minor potholes (Zagoda, 2004; Car & Zagoda, 2005; fig. 3 B, present text). In cases where relatively more compact lime­ stone is th rust over dolomite or flysch, water tight crushed zones form within the less-resistant underthrust rock. In appropriate hydrological conditions overhangs and minor caves will de­velop along the thrust plane. The thrust-paral­lel crushed zones are exceptionally transmissive. Fissured zones increase the permeability of the limestone significantly, and influence the direc­tion of the drainage (Zagoda, 2004). Deflector faults Early ideas about the hydrological aspects of deflecting fault structures in the karst were put forward by Jenko (1959). He felt that karst water-streaming simply crosses the main faults and predominantly follows “…all kinds of paral­lel fractures (viz. to the main fault) in order to avoid the master faults where there is a greater possibility of ongoing blockages caused by the breakdown and collapse of the tectonically dam­aged rock…” (Jenko, 1959, 158). Gams (1966) not­ed the presence of collector channels in the out­ flow system of Cerkniško polje. Important ideas about the role of neotectonic displacements in the karst were advanced by Bahun (1979). He felt that zones of reduced permeability related to the active faults are the reason that local step-like disruptions of the upper surface of the water ta­ ble are present. The issue of deflecting structures and thus the concept of deflector faults were considered in greater detail by Šušteršic and co-workers (2001) based upon study of the sample cases of the underground Pivka river (Postojns­ ka jama), the outflow system of Cerkniško polje (Karlovica Cave), and Logarcek Cave (one of the Planinsko polje drains). The latter authors clar­ified the hydrological significance of the deflect­ing structures, and pointed out their role in the development of cave systems. Related ideas were developed further by Šušteršic (2002, 2006). More recently the hydrological role of the Risnik de­flector fault (Kacna jama – extension of the Škoc­janske jame system) guiding the flow direction of the underground Reka river was discussed by Žvab Rožic et al., (2015). The per meability of spe­cific cataclastic rocks was established by Bauer and co-workers (2016), who presented meticulous descriptions of various cataclastic rocks within the central parts of selected fault zones in the Northern Limestone Alps (Austria). Generally, deflector faults are better-ex­pressed fractures or sections of sub-regional faults with well-developed internal ruptures i.e. crushed zones (Šušteršic et al., 2001; Žvab Rožic et al., 2015; figs 5a and 6, present text). The latter are fi lled with re-cemented cataclastic rocks in the form of compact tectonic breccias of various grain sizes. The cement may comprise tectonic clay or silt (fig. 6). Strongly cemented crushed zones take on the role of sub-vertical barrier zones, which may be totally imper meable, or nearly so (fig. 6). Just as with other lithological barriers they might leak small quantities of wa­ter during periods of low discharge. In cases of increased discharge, however, they partly de­flect and redirect the sur plus water flow paral­lel to the fault, along the crushed and fissured zones. Intricate cave channel systems, winding all along the fault zone, form within the feed­ er block (Šušteršic et al., 2001; Žvab Rožic et al., 2015). As a reflection of the var ying severity of fracturing within the fault zone, the under­ground water eventually encounters more per­ meable locations within the zone (fig. 6) and it turns squarely across the fault in the direction of the gradient into whichever adjacent block has a lower watertable. Just as in the karst of Slove­ nia, deflector faults are common and important structures within the entire Dinaric Karst (Ba­hun, 1979). The fundamental characteristic of deflector faults is their variability. Highly permeable, me­chanically unstable locally, and totally re-ce­mented segments alternate, both horizontally and vertically, at an approximate scale of several tens of metres or more (fig. 6). Considering that the fault planes are vertical or sub-vertical they may be recognized on the surface either as shal­low bogazes, as linear ridges, or as small scarps due to minor vertical component of movement, protruding above general ground-level, but dif­fering from the general “karren crest” morphol­ogy. Their role can be observed fully only where hydrological conditions are favourable. A large-scale example is provided by the (sur­face) intersection of the deflecting structure of the Idrija fault zone and the flat floor of Planinsko polje (figs. 11 A and B). At times of low water-lev­el the Unica river disappears almost entirely into numerous swallow-holes in the extreme south­eastern corner of the Planinsko polje basin, in the areas known as Milavcevi kljuci and Ribce (Car, 1982). Swallow holes have formed within intensive broken and fissured zones in the south­eastern marginal area of the Idrija fault zone (figs. 11 A and B). At higher water-levels, because the capacity of the ponors is limited due to the wide inner crushed zone of the Idrija fault, the main water body rebounds along the fault, head­ing northwestwards (figs. 11 A and B). The Unica River meanders across the flat floor of the Planin­sko polje between the Idrija and Zala faults and sinks into a number of swallow holes within the wider area of the fracture-zone of the Idrija fault (Car, 1982). On the northwestern side of the polje the Idrija fault zone becomes wider. The Unica crosses it and fi nally sinks at Podstene and Šk­ofji Lom. The deflecting role of the Idrija fault of­fers a convincing explanation of the hydrological situation in the Planinsko polje, as revealed by water-tracing experiments (Gospodaric & Habic, 1976). Hydrological development in the polje is, thus, comparable to situations encountered in the karst underground, such as in Kacna jama (Žvab Rožic et al., 2015). Structural framework and speleogenetic network Ignoring the properties of the rock itself, the basic structural elements, distributed in 3-D space, remain time stable. In the case of karsti­fied limestone they are bedding planes, litholog­ical changes and partings of other rocks, plus structural elements, including deflecting struc­tures. The listed structural elements pervade the limestone and extend through it continuously, yet they gradually change their properties. In order to explain karstological issues it suffices to fo­cus research upon a specified, well-defined block with a uniform structure that is large enough to enable recognition and understanding of all relevant structural elements. The structure re­vealed by such a spatially-limited limestone re­search-block is termed the structural framework (defi ned in the present paper). Variations of the structural elements in horizontal and vertical di­rections induce specific hydrological conditions within different parts of the structural frame­work and thus establish different conditions for karstification. Speleogenesis is permanently in progress within limestone massifs, conditioned by the general hydrological conditions, especially the base level and hydraulic gradient. Depending upon the actual structural conditions locally various initial corrosional widenings can de­velop into a plethora of different cavities, active and abandoned water channels, and other acces­sible or inaccessible speleological objects (Gams, 2003). All speleological objects and other karst phenomena of all types and sizes within a stud­ied block (speleogenetic space, -Šušteršic, 1991, 1999) form the (spatial) speleogenetic network (defi ned in the present paper). Development within it is also in fluenced by aspects of local­ly and regionally active tectonics. During the course of karstological research it is necessary 1. Dark-grey, bedded, limestone 2. Coarse grained, white, dolomite and limestone; micritic and oolitic limestone. 3. Different limestones and bituminous, coarse grained, dolomites 4. Grey grained and stromatolitic dolomite 5. Dip and strike of the dolomite beds 6. Fault and dip and strike of the fault plane 7. Thrust border 8. Crushed zone; tectonic silt and breccia 9. Broken zone 10. Densely fissured zone 11. Infrequently fissured zone 12. Solution doline and the direction of the central part dip 13. Collapse doline 14. Swallow-hole area 15. Underground stream direction Fundamentals of the karst surface arrangement to take into account the constantly changing str uctural conditions within the framework that Certainly, the most studied and the most dis-result from ongoing geological evolution, espe-cussed aspect of the karst phenomenon, world­cially neotectonics. wide as well as in Slovenian publications, is For the establishment of karst in general, and the karst surface itself. Gams (2003) presented particularly for the development of karst phe-a wide-ranging and thorough review (with ex­nomena in any limestone block, the structural tensive comments) of the earlier literature about framework is of fundamental importance. Struc-different surface karst forms and phenomena, tural elements, encompassed within the struc-as well as various aspects of the surface karsti­tural framework, direct both vertical percolation fication in Slovenia. Progress in understanding and horizontal streaming within the limestone, the role of remnants of speleological objects on and influence the spatial distribution and fre-the karst surface (Mihevc, 1996; Šušteršic, 1999), quency, as well as the size and shape of karst and its implications for the formation of specif­voids. ic landforms was far slower (Gospodaric, 1976; Habic, 1982; Car, 1982; 1986; Car & Šebela, 1997; Car & Zagoda, 2005). Whereas it appears obvious that ongoing denudation must have brought “in­herited” speleological objects to the karst sur­face, it was not until 1996 that Mihevc published his ground-breaking paper (Mihevc, 1996). Later, Šušteršic (1998, 1999), Šebela & Car (2000), and Mihevc (2001, 2007) expanded the ideas in sever­al ways, thus casting more light upon the signifi­cance of unroofed caves in the architecture of the karst surface. Habic (1986) was the first to draw attention to the complexity of the limestone karst surface in Slovenia, and he proposed the first, non-fluvial classification of karst surface entities. I n addition to the more obvious, larger-scale karst phenome­ na he identified and named a number of specific, small-scale geomorphic features. Unfortunately, he did not pursue their possible relationships to particular aspects of the background geology. By considering the roles of geological elements, subsequent studies of the karst relief (Šušteršic, 1987, 1994a, 1998, 2006; Mihevc, 1996, 2001, 2007; Car, 2001) extended and enriched Habic’s ideas. Recognition of the effects of continuously-ongo­ing surface denudation led to the inclusion and adaptation of unroofed caves and other relict karst voids within the accepted scope of surface relief entities. Consequently, in parallel with the general geological approach, detailed study of in­herited underground features became unavoida­ble (Mihevc, 1996, 2001; Šušteršic, 1998). As a re­sult of the steady mass-removal the karst surface migrates steadily downwards, thus intersecting elements of both the structural framework and the speleogenetic network. Gams (1966) estimated an overall lowering rate of 65 metres per million years for the karst surface in the hinterland of the Ljubljanica river. Northen Mediterranean limestone lowering rates measured in the Classical Karst (18 m/ Ma) and Istrian Karst (9 m/Ma (Furlani et al., 2009). De­tailed research in the region between the Idrijca and Vipava rivers (Habic, 1964) and the present author’s direct observations in the Idrija region suggest even greater surface lowering rates. Sub­ sequent geological mapping (Janež, et al., 1997) revealed similar figures. In this context, new ge­netic and functional connections were revealed between the structural framework and vari­ous karst phenomena, in both longitudinal and vertical directions. Providing other influences (hydrological and climatic conditions) remain constant, lateral and vertical changes of the frac­tured zones properties are the essential cause of the variability of surface karst phenomena (Car, 1986, 2001). Along with the fractured and thrust-paral­lel-zones, the main influences upon karstifica­tion are stratification and changes in lithology, especially interbeds or partings of other rock types. Surface karst structures associated with elements of the structural framework are gen­erally related to different evolutionary phases (Car, 1986). Denudational lowering of the karst surface induces changes to the speleogenetic net­work itself. Šušteršic (1999) noted that ongoing denudation brings underground karst features to the surface. Eventually, speleological objects forming integral parts of the speleogenetic net­work are simply destroyed. New surface karst features related to the structural framework are constantly evolving in parallel with the anni­hilation of the earlier ones. Or, in other words, cave voids constantly appear to migrate upwards within speleogentic space (Šušteršic, 1999). The same author (Šušteršic, 1998, 1999) characteri zed the disintegration of speleological objects close to, or at, the karst surface as the ultimate stage of speleogenesis (speleothanatosis). The same topic has also been tackled by several other Slovene researchers (Knez & Šebela, 1994; Geršl et al., Fig. 12. A section of the manuscript lithological and structural map of the area north of Laze at Planinsko polje. 1. Bedded, bituminous, limestone with thinly bedded, grained, dolomite inlays 2. Dip and strike of the dolomite beds 3. Fault and dip and strike of the fault plane 4. Crushed zone and tectonic breccia 5. Broken zone 6. Fissured zone 7. Solution doline 8. Solution doline and the direction of the central part dip 9. Recognized succession objects: U, V – collapse doline, j – unroofed cave 10. Individual limestone blocks in the broken zone 11. Weak spring in the weathered rock 0 100 200 300 400 500 Fig. 12. 1999; Šebela, 1999; Knez & Slabe, 1999). In his 1996 paper Mihevc concluded that the remains of former caverns (unroofed caves) are no longer speleological objects but have become surface entities. Many former speleological objects have been removed completely, others remain identifi­able and it is possible to deduce “what they used to be” (Šušteršic, 1999) All speleological relics are important contributors to the actual surface shaping (Šušteršic, 1999; Knez & Slabe, 1999; Mihevc, 2001). These were referred to as succes­sion objects by Car (2015; fig. 12, present text). Generally, succession objects are the still-identi­fiable remains of unroofed caves exhibiting var­ious degrees of disintegration, filled-in potholes (Šušteršic, 1978, 1999; Knez & Slabe, 1999; Šebe­la, 1999; Mihevc, 2001, 2007), collapse dolines (Šebela & Car, 2000), steep-slope (originally: broken) dolines (Car, 2001), and other indicators of former speleological objects, including rem­nant speleothem and clastic cave-sediment de­ posits (Mihevc, 2001, 2007; Šušteršic, 2004, 2017; Stepišnik & Mihevc, 2008). At present the criteria for determining dif­ferent types of genuine surface karst phenome­na, either in the formative phase, or in the phase of decay (Summerfield, 1991), remain vague. In contrast, the consecutive phases of unroofed cave disintegration, and their immediate conse­quences, were studied, at least in general terms, by Šušteršic (1998, 2004). Essentially the under­ground and surface karst objects are geological structures that have been reworked in a “karstic” way. Considering that they can be observed in different stages of (de-)formation it is of great im­portance to record as much field data as possible according to the methods presented in the initial paragraphs of the present paper (fig. 12). General recognition of consequent stages of surface karst phenomena development and unambiguous iden­tification of the succession objects is of course also important. It yields an insight into the “fourth di­mension” of the karst surface, i.e. into the part of the structural framework and speleogenetic network that has disappeared. It is also impor­tant to consider that the guidance of particular morphological objects may switch between dif­ferent (sub-) vertical features as they follow the most advantageous combinations of structures (Car, 1985). On the same essentially vertical route it might have come across a fissured zone and formed a characteristic fissure doline (Car, 2001, fig. 1B). At a lower level it might have encountered a local fault and its volume adopted the shape of a near-fault doline (Car, 2001). Or, virtually the opposite, if the crushed zone was re-cemented, a crushed-zone ridge could appear. Of course, dur­ing longer periods, different karst voids (elements of the speleogenetic network) might have ap­peared along the same vertical trend, adapting on the way to different elements of the pre-existing structural framework. Great skill and experience are needed to decipher details of the various ob­ject(s) that may possibly accumulate (emerge) in succession at the surface. Topographically-closed depressions of differ­ent dimensions, and their complementary, stand­alone, mounds or hillocks that exist in karst ter­rains, cannot be explained simply as a result of the intersection of the structural framework with the speleogenetic network, followed by the ef­fects of surface mass removal. Such geomorphic features are generally tied to the effects of neo­tectonics, which are studied with the help of dy­namic-kinematic models based upon the results of detailed structural mapping (Car, 1982; Car & Šebela, 1997; Car & Zagoda, 2005; Žvab-Rožic, Car & Rožic, 2015). Conclusions 1. Lithological and structural mapping can help to unravel details of the interaction between geological and speleogenetic features, including the effects of denudation. Regard must be paid to: (1) mass is being removed in solution; (2) the transport of denuded material is gravity-driven and ultimately vertical; and (3) accumulation of residual sediment is negligible (Šušteršic, 1982). 2. When mapping karstified limestones spe­cial attention must be paid to making numerous measurements of dip and strike angles, deter­mination of the spatial position of interbeds and partings of different lithologies, and other more subtle changes in the rock properties. Exhaustive collection of structural data and recognition of broken, crushed and fractured zones within and parallel to fault zones is essential. 3. Details of fracturing within fault zones vary both horizontally and vertically. For this reason the same degree (or style) of tectonic injury can­not be assumed to persist at points horizontally or vertically distant from a sample location. 4. Hydrological deflecting structures in the limestone karst – lithological barriers, thrust barriers and deflector faults – are of crucial im­portance to the underground hydrological situa­tion and, consequently, also to speleogenesis. 5. All structural elements within any specific limestone block contribute to a structural frame­work that is the starting point for the creation of the speleogenetic network. Speleogenetic net­works include all existent karst channels, wheth­ er voids or sediment-filled. They are dynamic, constantly changing systems. 6. Taking into account climatic and hydrolog­ ical in fluences, the karst surface is defined as the current intersection of the structural framework and the speleogenetic network, reworked and modified by present-day surface karstification and (possible) ongoing tectonic activity. 7. Karst terrain can be regarded as a dynamic, spatial, geological-hydrological and speleolog­ical-succession system, which is under the con­stant influence of ongoing tectonic movements. 8. Lithological and structural mapping of the karstified surface have proved to be highly pro­ductive and useful tools in deciphering both hy­drogeological and engineering-geological prob­lems in the karst. Strukturno - geološko kartiranje zakraselih apnencev Povzetek V prispevku pregledno razpravljam o dopol­njeni metodologiji in rezultatih podrobnega li­tološkega, strukturnega in geomorfološkega kartiranja zakraselih apnencevih terenov. Rezu­ltati kartiranja omogocajo ugotavljanje povezav med litološko-strukturno zgradbo in razlicni­mi kraškimi površinskimi pojavi, interpretacijo lege in razporeditve kraških površinskih pojavov v prostoru, razlago njihovih dimenzij in oblik ter medsebojnih povezav. Nadaljnji premisleki pripeljejo do globljega razumevanja dinamike razvoja kraškega površja, spoznavanja povezav s podzemljem in razlago ostankov nekdanjih spe­leoloških objektov na površju. Metodika kartiranja zakraselih apnencev slo­ni v osnovi na splošno uveljavljenih postopkih geološkega kartiranja dopolnjena s pogostejšim merjenjem vpadov in slemenitev plasti. Poleg razlicnih parametrov vrtac izrišemo tudi druge izstopajoce kraške pojave, predvsem udornice, požiralnike in vhode v jame in brezna. Po presoji izrišemo še vzpetine, tektonske brazde, prelomne stene, obliko znižanj in druge izstopajoce globe- li. Prav tako moramo biti pozorni na ostanke in sledove razlicnih nekdanjih speleoloških objek­tov. Beležimo tudi "nejasne primere", ki jim lah­ko kasneje posvetimo vecjo pozornost. Pri tem so nam v veliko pomoc LIDA R-ski posnetki. Vse ug­ otovljene geološke in druge podatke vpišemo in rišemo na terenu neposredno na karte v merilu 1: 10 000 in 1: 5000, izjemoma v vecjih merilih. Za zakrasevanja na lokalnem in regionalnem nivoju so temeljnega pomena lezike; oziroma stratifikacijska plastnatost; in litološke spre­membe v apnencih. Razlicni litološki vložki in lezike vplivajo v prvi vrsti na splošno prepust­nost apnencev ter usmerjenost in oblikovanost kraških pojavov. Ob primernih hidroloških in klimatskih po­ gojih razlicne litološke spremembe v apnencih usmerjajo pretakanje vode in vplivajo na razpo­red in obliko manjših površinskih kraških poja­ vov, vcasih tudi na velikost, obliko in prostorski razpored vecjih kraških globeli. Razlicni vložki neapnencastih kamnin, posebno še zgodnje in poznodiagenetskih dolomitov, so glede na de­belino in razprostranjenost lahko lokalnega ali regionalnega pomena. Znotraj dobro prepustnih apnencev predstavljajo hidrološke prepreke in so zato pomembni usmerjevalce pretakanja pod­zemne vode in tako vplivajo na razpored spele­oloških objektov. Tudi samo delno dolomitizira­ni apnenci se hidrološko in geomehansko precej drugace "obnašajo" kot cisti apnenci. Na površju dolomitni vložki in dolomitizirani apnenci hitre­je razpadajo kot apnenci in vplivajo na oblikova­nost površja. Deformacije ob gubah, narivih in razlicnih prelomih so tudi v apnencih soglasne s splošnimi teorijami deformacij ob plikativnih in disjunk­tivnih tektonskih deformacijah. Številne od­klone od teoreticne geometrijske razporeditve tektonskih elementov; razložimo z litološkimi spremembami vzdolž prelomnih con, z razlic­nimi dolžinami premikov ob prelomnih conah, vecfaznim premikanjem in spreminjanjem pretr­tosti vzdolž tektonskih con; oziroma energijo, ki se je ob posameznih prelomih sprostila. Pri opisu in razlagi današnjih razmer na kraških terenih je potrebno upoštevati tudi vpliv aktualnih tekton­skih premikanj. Za pravilno razlago strukture je potrebno cim pogostnejše merjenje vpadov in slemenitve plasti, kljub morebitnemu subjektivnemu obcutku, da se oba elementa v prostoru ne spreminjata ali ne­znatno spreminjata. Tako dobimo osnove za ugo­tavljanje njihovega vpliva na potek zakrasevanja in vpogled v morebitne plikativne deformacije v obliki vcasih tudi zelo velikih in blagih antikli­nalnih ali sinklinalnih upognitev plasti. Pri gu­banju se dogajajo medplastni zdrsi, pri tem na­stajajo zdrsne lezike, ki predstavljajo prednostne smeri za pretakanje vode in zakrasevanje. Locitev med razpoko in prelomom je dogovor­na, prehodi med njima so zvezni. Za preucevanje kraškega površja povsem zadostuje, ce s prelo­mom oznacimo nezveznost v kamnini, ki ji lahko sledimo vsaj nekaj deset metrov, ostale krajše ne­zveznosti pa štejemo med razpoke. V okviru pre­lomne cone, tlacne ali natezne, se isti tipi razpok združujejo v nize, ti pa v snope, ki so dolgi od nekaj deset do vec sto metrov. Razpoklinski sno­pi, ki pripadajo vec prelomnim smerem, se lahko na nekem omejenem terenu med seboj združujejo ali pod razlicnimi koti križajo. Tako razpokano obmocje oznacimo kot razpoklinsko cono. Pri razlagi velikosti in oblikovanosti kraških pojavov ter navezanost posameznih kraških ob­jektov na strukturne elemente in njihove ge­netske posebnosti; je potrebno upoštevati raz­licne stopnje pretrtosti apnencev. V prelomnih conah spremenjene (tektonsko prizadete) kam­nine v splošnem oznacimo kot pretrte kamnine. Glede na stopnjo pretrtosti locimo zdrobljene, porušene in razpoklinske cone . V odvisnosti od litologije in mehanskih last­nosti ob narivnicah stikajocih kamnin ter ener­gije, ki se je pri narivanju sprostila, so nasta­le zapleteno zgrajene obnarivne pretrte cone. So subhorizontalne in bolj ali manj vzporedne z glavno narivno ploskvijo. Razvite so tako v podrinjenem kot tudi narinjenem bloku. V ge­netski povezavi z razpoklinskimi obnarivnimi conami so obnarivne zdrsne lezike, ki imajo po­membno vlogo v speleogenezi in pri oblikovanju kraškega površja. Njihova izrazitost in pogost­nost je odvisna tudi od lege plasti v narinjenem kot tudi podrinjenem bloku. V zakraselih apnencih ponavadi opazujemo ob razlicnih prelomih dobro defi nirane prelom­ne cone. Posebno izrazite so ob zmicnih prelo­mih, kjer locimo notranjo in obicajno dve zu na nji prelomni coni. Notranje prelomne cone so zapol­njene z razlicnimi kataklasticnimi kamninami v obliko razlicno velikih lec, ki so med seboj locene z notranjimi prelomnimi ploskvami. Po notranji prelomni coni, ki je navzven najveckrat omejena z mejnimi prelomnimi ploskvami, po­teka tudi glavna prelomna ploskev. Soglasno s spreminjanjem pretrtih con v vzdolžni in ver­tikalni smeri se ob danih hidroloških pogojih spreminja tudi prepustnost ob prelomih v verti­kalni in horizontalni smeri. Zaradi tega nasta­nejo na površju vzdolž istega preloma razlicni kraški pojavi. Pomembni strukturni elementi na krasu so hidrološke zadrževalno-zaporne strukture. Gle­de na njihovo navezanost na razlicne litološke in tektonske elemente locimo litološke, obnarivne in prelomne hidrološke zadrževalno-zaporne strukture. Naštete strukture niso neprepustne preg rade, pac pa slabše prepustna obmocja sredi dobro prepustnih apnencev, ki vodi ob doloce­nih vodostajih le zapirajo pot in otežujejo pretok skozi strukturno obmocje. Njihova hidrološka vloga je dinamicna in se spreminja v odvisnosti od notranje zgradbe zapor in kolicine vode. Za­d rževalno-zapor ne str u ktu re ob n i zki h vodosta­jih vodo ponavadi v celoti prepušcajo, ob visokih in poplavnih razmerah jo zaradi premajhne pre­ pustnosti zadržujejo in ‚odbijajo‘. Usmerjajo jo po prepustnejših conah vzdolž struktur in sicer po porušenih in razpoklinskih conah, lezikah ter poroznih-satastih kamninah. Opisana vloga zadrževalno-zapornih struktur ustvarja pogoje za usmerjeni potek speleogeneze in nastajanje tudi velikih zapletenih jamskih sistemov. Ce v zakraselih apnencih odmislimo ap­nencevo kamnino, ostanejo le prostorsko raz­porejeni strukturni elementi in sicer lezike, litološke spremembe, vložki drugih kamnin, tektonske deformacije in hidrološko zadrže­valne strukture. Našteti strukturni elementi prepredajo apnenceve kamnine in gradijo pre­žemajoco prostorsko mrežo. Ker se struktur­ni elementi spreminjajo in razprostirajo »v ne­skoncnost«, ponavadi reševanje krasoslovnih problemov omejimo le na dolocen raziskovalni blok, ki mora biti tako velik, da lahko doloci­mo in razumemo vse strukturne elemente, ki v njem nastopajo. V takem, prostorsko omejenem raziskovalnem apnencevem bloku, govorimo o strukturni rešetki. Spreminjanje strukturnih elementov v horizontali in vertikali ustvarja v razlicnih delih strukturne rešetke svojske hi­drološke pogoje in s tem spreminjajoce pogoje zakrasevanja. Podzemne speleološke objekte in pojave vseh oblik in velikosti v nekem raziskovanem bloku (speleogenetski prostor) združimo v prostorsko speleogenetsko mrežo. Na dogajanje v njej vpliva­ta tudi aktivna lokalna in regionalna tektonika. Z zniževanjem kraškega površja se dogajajo spremembe v strukturni in speleogenetski re­šetki. Medtem, ko v okviru strukturne rešetke zaradi zniževanja terena poleg izginjanja sta­rejših nastajajo ob socasnem zakrasevanju tudi novi površinski kraški objekti, se odvija v okvi­ru speleogenetske rešetke le postopno izginjanje speleoloških objektov. Ostanki nekdanjih pod­zemskih jam seveda niso vec speleološki objekt pac pa površinski objekti. Veliko nekdanjih spe­leoloških objektov je že povsem izginilo, drugi so še razpoznavni in lahko ugotovimo, kaj so ne­ koc bili. Vsi speleološki relikti, ali bolje receno speleološki objekti v zadnji fazi speleogeneze, pomembno sooblikujejo kraško površje. Imenu­jemo jih nasledstveni objekti. K njim prišteva­ mo razlicno spoznavne ostanke brezstropih jam in zasutih brezen, udornic in por ušnih vrtac in druge sledove nekdanjih speleoloških objektov ter tudi ostanke jamskih sedimentov. Na podlagi povedanega lahko kraški ter­en opredelimo kot aktualen presek struktur ne rešetke in speleogenetske mreže. V pogledu pro­cesov pa je kraško površje dinamicen prostor­sko hidrogeološki in speleološki-nasledstveni sistem, ki se spreminja pod stalnim vplivom aktualnih tektonskih premikanj in klimatskih razmer. Za zakljucek naj omenim, da smo idrijski ge­ologi metodiko podrobnega strukturnega karti­ranja uspešno uporabljali tudi pri reševanju hidrogeoloških in inženirsko-geoloških prob­lemov v najrazlicnejših kamninah na številnih lokacijah po Sloveniji. Acknowledgements I thank my friends Dr. France Šušteršic and Jože Janež for accurate reading of the manuscript and for their substantive comments and suggestions, which were important to improving the present text. Thanks also to the former for his punctilious translation of the Slovene manuscript into English. Special thanks to Dr. David Lowe, who not only smoothed the transla­ted draft and suggested improvements to the geologi­cal terminology, but also contributed to the scientific discussion. 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CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.011 Nahajališca zemeljskega plina na naftno-plinskem polju Petišovci Natural gas reservoirs on the oil-gas field Petišovci Jernej KERCMAR Petrol Geo, proizvodnja ogljikovodikov d.o.o., Mlinska ulica 5D, SI-9220 Lendava, Slovenija; e-mail: jernej.kercmar@petrol.si Prejeto / Received 11. 7. 2018; Sprejeto / Accepted 22. 10. 2018; Objavljeno na spletu / Published online 20. 12. 2018 Kljucne besede: ogljikovodiki, naftno-plinsko polje Petišovci, razvoj nahajališca Key words: hydrocarbons, oil-gas field Petišovci, reservoir development Izvlecek Za nastanek nahajališc z ogljikovodiki so potrebni trije pogoji in sicer; maticna kamnina, v kateri ogljikovodiki nastanejo (podlaga ali talnina), kolektorska porozna kamnina, v katero se ogljikovodiki ujamejo in zgornja neprepustna kamnina (krovnina). Poleg geološke strukture so potrebni še primerna temperatura, tlak in cas, da organska snov pri redukcijskih pogojih preide faze diageneze in generira ogljikovodike, kot jih poznamo danes. Vsako nahajališce ogljikovodikov, ki se odkrije in ima ekonomsko pomembne zaloge za proizvodnjo, gre skozi pet stopenj razvoja polja. Najprej se izvedejo geološke, geofi zikalne, petrofi zikalne, rezervoarske raziskave, katerih rezultati se nato razložijo in ovrednotijo z 2-D in predvsem s sodobnimi 3-D geološkimi modeli. Sledi razvoj celotnega polja, v okviru katerega se ovrednotijo geološke in bilancne zaloge vseh nahajališc. Sledi faza proizvodnje in na koncu faza sanacije polja. V Sloveniji smo najvec zemeljskega plina proizvedli iz nahajališc »Petišovci globoko« in sicer od leta 1963 do leta 2017 skupaj vec kot 341 milijonov Sm3. V zadnjih letih se polje dodatno razvija z obdelavo perspektivnih nahajališc zemeljskega plina v tako imenovani seriji 'K' (»Petišovci globoko«). Od leta 2017 poteka proizvodnja plina iz vrtin Pg-10 in Pg-11A. Abstract Three conditions are required for the existence of hydrocarbon reservoirs: source rock (usually basement or footwall), collector (porous rock in which the hydrocarbons are caught), and upper impermeable rock (hanging wall). In addition to a geological structure, temperature, pressure and time are needed for the organic matter to pass through the diagenesis phase into hydrocarbons, as we know them today. Every hydrocarbon deposit found and having economical reserves for production passes five stages of the life cycle of the reservoir. First, geological, geophysical, petrophysical and reservoir exploration is carried out, and then results of these explorations are evaluated by 2D and 3D geological models. Next stage is evaluation of entire field potential (in-place) and proved reserves of all hydrocarbons-bearing reservoir strata (reservoirs). Afterwards, the most important stage is production and the end phase with the remediation of the field. In Slovenia, most of the natural gas was produced from the “Petišovci globoko” reservoirs in the years between 1963 and 2017, totaling to more than 341 million Sm3. In recent years, the field has been further developed by processing prospective natural gas reservoirs in so-called ‘K’ series (“Petišovci globoko”). Since 2017, the production of gas from two new wells, Pg-10 and Pg-11A, takes place. Uvod Eden izmed kriterijev stabilnega gospodar­stva vsake države je cim manjša energetska od­visnost. Kljub temu, da se svet vse bolj usmerja v iskanje in razvoj alternativnih in obnovljivih virov energije, je trenutno še vedno najcenejša in najcistejša fosilna energija zemeljski plin. V preskrbi s primarno energijo razvitih dežel za­vzema zemeljski plin okoli 25 odstotni delež (za nafto in pred premogom), pri nas pa razmeroma nizkega, le okoli 12 % (Nerad, 2012). S pojmom ogljikovodiki opredeljujemo fosil­ne energetske vire, kot so surova nafta, zemeljski plin in plinski kondenzat. V nadaljevanju jih skrajšano imenujemo nafta, plin in kondenzat. Prvotno so nastali v maticni kamnini, v kateri je bila organska snov rastlinskega in živalskega porekla odložena v redukcijskih pogojih, ohra­njena v sedimentih, šla skozi procese diageneze in zorenja ter nastanka naftnih in/ali plinastih snovi. Tem procesom je sledila manjša ali vecja migracija ogljikovodikov v zbirne ali kolektorske plasti. V Sloveniji imamo v Panonskem bazenu zna­no le eno gospodarsko pomembno obmocje naha­jališc nafte in zemeljskega plina. To je obmocje Doline in Petišovcev nekoliko jugovzhodno od Lendave, znano tudi kot naftno-plinsko polje Dolina-Petišovci, obratujoce od leta 1943 dalje. Nahajališca omenjenega polja, ki so neogenske starosti, delimo na plitka nahajališca v globinah od 1000 m do 2000 m in na globoka nahajališca v globinah od 2000 m navzdol do predterciar ne podlage. Slednja so danes ekonomsko bolj per­spektivna kot plitka. Nosilec rudarske pravice za izkorišcanje mi­neralnih surovin – ogljikovodikov na podrocju Murske depresije je družba Geoenergo d.o.o. Ang­leška družba z registrirano podružnico v Slove­niji Ascent Slovenia Limited, je glavna investitor­ka na podrocju pridobivanja zemeljskega plina na naftno-plinskem polju Petišovci-Dolina, uprav­ljavec rudarske infrastrukture za pridobivanje ogljikovodikov je Petrol Geo, proizvodnja oglji­kovodikov d.o.o. Ker je proizvodnja nafte danes prakticno zanemarljiva, bo tematika tega clanka poudarjeno obravnavala le plinska nahajališca. Razvoj nahajališca in proizvodnja zemeljskega plina Ko zaslišimo besedi nafta ali pa zemeljski plin, pogosto pomislimo na pokrajino, posejano z vrtalnimi stolpi in prepredeno z naftovodi in plinovodi. Kot na vseh podrocjih je tudi na naf­tnem podrocju tehnologija zelo napredovala, saj nam ta omogoca manjšo degradacijo okolja tako v casu vrtanja kot tudi v casu proizvodnje. Po koncani proizvodnji je treba vrtine sanirati, ure­diti okolje v primerno stanje, cim bolj podobno pr votnemu, in vzpostaviti držav ni monitoring naftno-plinskega polja (opazovalne vrtine). Osnovni pojmi Za lažje razumevanje spodnjega besedila bomo na kratko opisali nekaj osnovnih pojmov, ki se nanašajo na naftno in plinsko industr ijo (Ci­ keš, 2013): -Ogljikovodik (angl. hydrocarbon) je or­ganska spojina, ki jo sestavljata izkljucno ogljik in vodik. Vecino ogljikovodikov na Zemlji najdemo v surovi nafti in zemel­jskem plinu. -Surova nafta (angl. crude oil) je tekocina, ki jo najdemo v Zemlji in je sestavljena iz ogljikovodikov, organskih spojin in majh­nih (slednih) kolicin kovinskih elementov. -Plin v plinski kapi (angl. gas cap) je plin v strukturni pasti in se nahaja nad nafto. -Naftni plin (angl. associated gas) je zemel­jski plin, ki je v zgornjem delu nahajališca in je v kontaktu z nafto (plin v plinski kapi) imenovan kot prosti zemeljski plin (angl. gas cap) ali raztopljen zemeljski plin (angl. solution gas) v nafti. -Zemeljski plin (angl. natural gas) je plin, sestavljen predvsem iz metana, ki pa lahko vsebuje tudi majhne kolicine dr ugih ogljik­ovodikov: etana, propana, butana, pentana in heksana, ki jih imenujemo s kratico "C1 ­C6" plini. -Plinski kondenzat (angl. condensate) je ze­meljski plin, ki je v nahajališcnih pogojih v plinastem agregatnem stanju, pri proiz­vodnji pa se plin kondenzira in se ga prido­bi v tekocem stanju. -Nahajališce (angl. reservoir), imenovano tudi kolektor, kolektorska plast ali kole­ktorski sloj je kamnina, v kateri so v po­rah (medzrnskih ali razpoklinskih) ujeti akumulirani ogljikovodiki. Najpogostejša nahajališca so v klasticnih in karbonatnih kamninah, lahko pa tudi v magmatskih in metamorfnih. Ime za nahajališce je tudi ležišce, ki pa se v novejšem casu opušca (Pavšic, 2013). -Naftno in/ali plinsko polje (angl. oil and/or gas field) je doloceno obmocje na površini, kjer poteka pridobivanje ogljikovodikov in je po naši rudarski zakonodaji omejeno kot pridobivalni prostor. -Naftna geologija (angl. oil geology) je veja geologije, ki temeljno in uporabno razisku­ je nahajališca ogljikovodikov in ocenjuje ter vrednoti njihove vire in zaloge. Pri tem upošteva izsledke sorodnih in dopolnjujo­cih ved: stratigrafije, geofizike, petrologije in petrofizike, rezervoarskega inženirstva, kemije in fizike ogljikovodikov itd. Proces od raziskovanja do proizvodnje oglji­kovodikov zajema pet razvojnih stopenj, od od­krivanja ogljikovodikov do sanacije naftnega in/ali plinskega polja ter monitoringa. V nadalje­vanju je opisana vsaka stopnja glede na dejavnosti, delovna mesta, stroške in casovne okvire. Stopnje razvoja polja Raziskovanje Raziskovanje nafte in plina je metoda, ki jo uporabljajo naftni geologi in geofiziki za iska­nje ogljikovodikov na obmocjih celin (angl. on­-shore), ali izven njih (angl. off-shore) – v morjih. Sestavljena je iz iskanja virov in zalog nafte in/ ali plina z uporabo primarnih tehnologij, zlasti geofi zikalnih globokih seizmicnih raziskav in raziskovalnih vrtin (sl. 1a). Raziskovanje je dra­ga in tvegana operacija, ker se z njim povezani odhodki obicajno vrednotijo v milijonih evrov in pri tem v povprecju saka druga vrtina od treh (Cikeš, 2013) ne vsebuje sledi ogljikovodikov. Zato je na potencialnem obmocju potrebno izvrtati vecje število vrtin, preden se lahko ugotovi pra­vo velikost naftnega in/ali plinskega nahajališca, kar pa lahko traja vec let ali celo desetletij. Med raziskovalnim vrtanjem se pridobivajo pomembni podatki na podlagi vzorcev kamnin (izpirkov navrtanega materiala), vzorcev fluidov (nafta in plinski kondenzat), vzorcev plina (ze­meljski plin) in karotažnih meritev (dolocitev lastnosti kamnin – tip kamnine, poroznost, na­sicenost z ogljikovodiki itd.) z namenom, da se lahko dolocijo (Jahn et al., 2003): -perspektivnost nahajališca, -tipi surove nafte in zemeljskega plina v na­ hajališcu, -prostor nina nahajališca (korelacija vec vrtin). Za vsako delo, ki zahteva fi zicni napor (seiz­micne raziskave, vrtanje, vzorcenje itd.), se mo­rajo upoštevati visoki standardi glede var nosti in zdravja ljudi pri delu, ki ga narekujejo zakonoda­ja in pravilniki. Sl. 1. Stopnje razvoja naftno-plinskega polja (Tanoh, 2016), a - raziskovanje in pridobivanje podatkov, b - obdelava podatkov in izdelava 3D geoloških modelov, c - upravljanje proizvodnje naftno-plinskega polja, d - vzdrževanje proizvodnje na naftno­plinskem polju. Fig. 1. Stages of oil and gas field development, a - Research and data acquisition, b - Data processing and preparation of 3D geological models, c - Oil and gas field production, d - Maintenance of production on oil and gas field. Ocenjevanje Ko podjetje uspešno opravi raziskovalno vrta­nje in odkrije nafto ali plin, je naslednja stopnja ocenjevanje razvojnega cikla nahajališca. Glavni namen te faze je zmanjšati negotovost ali mož­nost izgube zacetnih investicij glede perspektiv­nosti in velikosti naftnega in/ali plinskega polja. Med ocenjevanjem se poleg vrtin za raziskovanje izvrta tudi vec vrtin za zbiranje informacij, kot so na primer jedra v dolocenih inter valih nahaja­lišc in podrobnejše raziskave na njih (geomehan­ske znacilnosti, struktura in tekstura kamnin, poroznost itd). Druga seizmicna raziskava se po­novi, ce je potrebno, da bi z njo dobili boljšo po­dobo nahajališca. Te dejavnosti trajajo še nekaj let in stanejo desetine do stotine milijonov evrov, kar zavisi od velikosti polja (Jahn et al., 2003). Vec seizmicnih raziskav in raziskovalnih vrtin pomaga naftnim geologom, geofizikom in rezer­voarskim inženirjem razumeti nahajališca (sl. 1b). Na primer, kako se spreminjajo lastnosti ko­lektorskih kamnin in s tem posledicno razpore­jenost nafte in plina v prostoru, koliko nafte ali plina je v nahajališcu in kako hitro se bosta nafta in/ali plin gibala (migrirala) skozi nahajališce v casu proizvodnje. Po uspešni stopnji ocenjevanja se podjetje odloci, ali se naftno ali plinsko polje lahko dejansko razvije ali ne. Nastanek polja Faza nastanka naftno-plinskega polja se poja­vi ob uspešni oceni in pred zacetno proizvodnjo. Glavne dejavnosti so (Saridja, 1985): -Oblikovanje nacrta za razvoj naftnega ali plinskega polja z vkljucitvijo zadostne­ ga števila vrtin, potrebnih za proizvodnjo nafte in/ali plina. Nacrt pripravijo geologi, geofi ziki in rezervoarski inženirji. -Odlocitev o uporabi tehnologije vrtanja za proizvodne vrtine, ki jo utemeljijo geoteh­nologi, strokovnjaki za vrtanje, rudarski strojniki. -Odlocitev o velikosti proizvodne zmoglji­vosti polja (ocena proizvodne zmogljivosti polja skozi casovno obdobje) narekuje pot­rebe po objektih za obdelavo nafte ali plina (rafinerije, plinske postaje itd.), ki jo ute­meljijo inženirji za procesno tehniko. -Odlocitev glede transporta nafte in plina, ki jo opredelijo inženirji logistike. Razvojni nacrt se zakljuci z v pr vi fazi izvrta­nimi proizvodnimi vrtinami in zgrajenimi vse­mi potrebnimi objekti za procesiranje ogljiko­ vodikov. V razvojni nacrt so vkljuceni inženirji s podrocja geotehnologije, logistike in procesne tehnike, ki ustvarijo pogoje za proizvodnjo oglji­kovodikov iz nahajališc (sl.1c). Pri tem se ustvar­jajo številne možnosti zaposlovanja, kjer ljudje lahko sodelujejo pri izgradnji proizvodnih objek­tov. Najpomembnejša prednostna naloga pri tem je varnost. Tveganje za nesreco je v tej fazi naj­višje zaradi števila ljudi, ki se ukvarjajo s pri­ pravo delovišca in samim vrtanjem (Jahn et al., 2003). Razvoj naftnega polja lahko stane vec milijard evrov in obicajno traja 5-10 let, odvisno od lokaci­je, velikosti in kompleksnosti objektov ter števila potrebnih vrtin. Razvoj na kopnem je razmeroma veliko cenejši od razvoja na morju. Naftna in plinska podjetja naredijo na tej sto­pnji razvoja polja dokumentacijo o racionalnih pricakovanjih uspešnosti pridobivanja ogljikovo­dikov z analizo stroškov raziskovanja, stroškov razvoja ter dobicka pri prodaji ogljikovodikov. Ra­zvojni cikel se izvede, ce so izpolnjeni vsi pogoji po ustrezni rudarski in okoljevarstveni zakonodaji. Sl. 2. Vrtalni stolp na plinski vrtini Pg-3 in površinska crpalka na naftni vrtini Pt-1 (vir: Petrol Geo, 2018). Fig. 2. Drilling rig on the gas well Pg-3 and surface pump on the oil well Pt-1 (source: Petrol Geo, 2018). Proizvodnja Proizvodnja je zadnja faza, v kateri se pridobi­vajo ogljikovodiki iz naftnega in/ali plinskega po­lja ter prvi prihodek iz prodaje nafte in/ali plina. Po tem, ko prihodki presežejo zacetno naložbo in fiksne stroške podjetja, se zacne ustvarjati dobi­cek. Proizvodnja na naftno-plinskem polju lahko traja vec let, do okoli 40 let, odvisno od velikosti, oblike in tipa kamnin (pešcenjaki, skrilavci, kar­bonati in druge kamnine) v nahajališcu (sl. 1d). Operaterji delajo v izmenah za nemoteno pro­izvodnjo. Inženirji skrbijo za pravilno delovanje proizvodnega procesa (nadgrajevanje, izboljševa­nje), rezervoarski inženirji pa spremljajo stanje zalog v nahajališcih in išcejo nova perspektivna nahajališca (Jahn et al., 2003). Sanacija Sanacija je izraz, ki se uporablja za opis vzpo­stavitve degradiranega okolja zaradi izkorišcanja nafte in/ali plina v stanje, ki bo cim podrobnejše pr votnemu stanju in prijazno okolju brez škodlji­vih vplivov na zdravje ljudi in živali. Prvotnega stanja sicer ni mogoce nikoli povsem povrniti, zato pa se upoštevajo najvišji standardi za izved­bo sanacije, in sicer (Jahn et al., 2003): -cementiranje proizvodnih intervalov v vr­ tinah, -postavitev cementacijskih cepov v vrtinah, -odstranitev ustij vrtin in pritrditev slepih prirobnic, -odstranitev naftovodov in plinovodov, -odstranitev vseh ostalih objektov (plinskih postaj, rafinerij itd.), -nekaj vrtin se preuredi za monitoring na­ hajališc, ki ga izvaja državni monitoring. Odkritje naftno-plinskega polja Petišovci-Dolina Naftno-plinsko polje Petišovci sodi po naf­tno-geološki prostorski opredelitvi v Mursko de­presijo (Plenicar, 1954; Mioc & Markovic, 1998). Zacetki raziskav nahajališc ogljikovodikov na obmocju Murske depresije segajo v sredino 19. stoletja, ko so na Hrvaškem v neposredni bliži­ni meje s Slovenijo v vaseh Peklenica in Selnica zaceli pridobivati nafto na površinskih izvirih. Raziskave nahajališc ogljikovodikov so se od tod postopno razširile tudi proti severu v Prekmurje oziroma slovenski del Murske depresije. Na za­cetku 2. svetovne vojne so bile po obsežnih po­vršinskih geoloških raziskavah širšega obmocja Sl. 3. Prikaz lokacije naftno-plinskega polja Petišovci-Dolina v pridobivalnem prostoru Murske depresije (vir: Petrol Geo, 2018). Fig. 3. Location map of the oil and gas fields Petišovci-Dolina within the exploitation area of the Mura depression (source: Petrol Geo, 2018). Murske depresije izvedene gravimetricne meritve (Plenicar, 1954). Na osnovi pridobljenih podatkov je bila leta 1942 najprej dolocena lokacija in nato izvrtana vrtina Dolina 1 (D1) do globine okrog 1460 m in leta 1943 vrtina Petišovci-1 (Pt-1) do globine okrog 1750 m. Crpalko na naftni vrtini Pt-1 kaže slika 2. Tako sta bili odkriti naftno-plinski polji Do­lina in Petišovci (sl. 3). Kmalu je bilo ugotovlje­no, da je naftno-plinsko polje Dolina sestavni del velikega madžarskega polja Lovászi in da je naftno-plinsko polje Petišovci samostojna antik­linalna struktura, ki se nahaja na severnem delu Ormoško-selniške antiklinale (antiforme). Po odkritju naftno-plinskega polja Petišovci z raziskovalno vrtino Pt-1 se je še v casu 2. svetovne vojne nadaljevalo z izgradnjo razdelovalnih vrtin Pt-2 in Pt-3 in po 2. svetovni vojni do leta 1958 z izgradnjo še 107-ih proizvodno-razdelovalnih vrtin. Z dodatnimi seizmicnimi meritvami v letu 1960 je bilo ugotovljeno, da se na obmocju naftno­-plinskega polja Petišovci, pod zgornjemiocen­skimi sedimenti, nahaja perspektivna struktura srednje in spodnjemiocenskih sedimentov (Bokor, 1986). Leta 1961 je sledila izgradnja prve globo­ke raziskovalne vrtine Pg-1 do globine približno 2970 m, s katero so bila odkrita globoka plinska nahajališca, tako imenovana nahajališca »Pe­tišovci globoko«. V obdobju od leta 1961 do leta 1990 je bilo skupno izvrtanih 9 vrtin, ki so vse ra­zen ene (ki ni bila dokoncana) navrtale slabo pre­pustna plinska nahajališca »Petišovci globoko« (sl. 2 - primer plinske vrtine Pg-3). Po izvedbi in interpretaciji 3D seizmicnih meritev sta bili leta 2011 izdelani še dve globoki vr tini (Pg-10 in Pg-11A), ki sta bili leta 2017 vkljuceni v proizvodnjo. Geološka zgradba naftno-plinskega polja Petišovci Za nastanek nahajališc ogljikovodikov morajo biti izpolnjeni trije pogoji (sl. 4). Obstajati morajo (Nedeljkovic, 1963): -maticne kamnine, -porozne in prepustne rezervoarske kam­nine, v katerih se ogljikovodiki akumuli­rajo, -neprepustna krovnina nahajališca (angl. cap rock) ali drugi mehanizmi, ki pre­ precujejo uhajanje ogljikovodikov. Naftno-plinsko polje Petišovci delimo v osno­vi po vertikali v 5 glavnih nahajališc ogljikovo­dikov, ki si sledijo od vrha navzdol po naslednjem vrstnem redu (od površine terena): -Paka, serija naftnih nahajališc (1080­ 1200 m), -Ratka, serija naftnih nahajališc (1300­ 1400 m), -Lovaszi, serija plinskih nahajališc (1550­ 1600 m), -Petišovci, serija naftnih nahajališc (1650­ 1700 m), -»Petišovci globoko«, serija plinskih naha­jališc (od 2000 m navzdol – terciarna pod­laga). V primeru Petišovcev so mnogoštevilni pli­nonosni in/ali naftonosni sloji bolj ali manj po­rozni miocenski neogenski pešcenjaki z vmesni­mi tankimi plastmi laporjev. Naftonosne in/ali plinonosne plasti so debele od nekaj metrov do nekaj deset metrov in približno enako debele so tudi vmesne neprepustne (izolacijske) plasti lapo­rovcev. Sl. 4. Poenostavljen geološki prerez skozi antiformno nahajališce ogljikovodikov (Internet 1). Fig. 4. Generalized geological cross-section through an antiform hydrocarbon reservoir (Internet 1). Nahajališca zemeljskega plina na naftno-plinskem polju Petišovci Sl. 5. Struktura naftnih nahajališc Petišovci in plinskih nahajališc “Petišovci globoko” (Kercmar, 2014). Fig. 5. Structure of oil reservoirs Petišovci and gas reservoirs “Petišovci globoko” (Kercmar, 2014). Znotraj naftno-plinskega polja Petišovci je trenutno najbolj perspektivno plinsko nahajali­šce »Petišovci globoko«, ki je predmet natancnej­še razlage v nadaljevanju clanka. Nahajališca »Petišovci globoko« Strukturno-tektonska zgradba Najstarejše ogljikovodikonosne karpatijske in badenijske plasti tvorijo na obravnavanem ob­ mocju kompleksno antiformno strukturo z nekaj maksimumi, ki predstavljajo »strukturne pasti« za akumulacijo oziroma »ujetje« ogljikovodikov v njih. Omenjena antiforma (sl. 5) v precnodinar­ski smeri SW-NE je v geološki literaturi (Mioc & Markovic, 1998) imenovana kot Ormoško­selniška antiklinala. Interpretacije v 1980-ih le­tih (Djurasek, 1988) so pokazale, da je omenje­na antiforma dvignjena (iztisnjena) ob dveh re­verznih prelomih, Ljutomerskem in Donackem prelomu. Antiformo sekajo precni prelomi, ki jo delijo v vec blokov (Mioc & Markovic, 1998). Gre za pet glavnih blokov z znacilno strukturo hor­stov in vmesnih grabnov. Vsak blok zase predsta­vlja posebno hidrodinamsko enoto. Litostratigrafske razmere Stratigrafija plasti polja Petišovci je na osnovi velikega števila litoloških in paleontoloških pre­iskav vzorcev izvrtanih kamnin ter korelacij z geofi zikalnimi elektrokarotažnimi (EK) diagra­mi potrjena kot kronostratigrafska in litostra­tigrafska zgornjeterciarna (neogenska) starost plasti, znacilna za Mursko depresijo. Terciarni sedimenti so razvršceni v tri formacije. Najsta­rejša je Mursko-soboška formacija, ki se po no­vem deli na Haloško in Špiljsko formacijo (Jelen & Rifelj, 2011), nad njo je v nor malnem zaporedju Lendavska formacija in nato najmlajša Murska formacija (sl. 6). Murskosoboška formacija (Špiljska in Haloška formacija) zajema v stratig rafskem zaporedju ob­dobja karpatija, badenija, sarmatija in spodnjega panonija. Karpatijske, badenijske in sarmatijske plasti sestavljajo trdo vezani drobno- do srednje­zrnati kremenovi pešcenjaki s sljudo, meljevci in trdi do srednje trdi meljasti laporji. Spodnje­panonijske plasti pa sestavljajo srednje vezani drobno-do srednjezrnati kremenovi pešcenjaki s sljudo, lapornati pešcenjaki, meljevci in srednje trdi laporji (Bokor, 1986; Lisjak, 1988). Sl. 6. Presek naftno-plinskega polja Petišovci-Dolina z litološkim stolpcem (vir: Ascent Resources, Geomega, 2012). Fig. 6. Cross-section through the Petisovci-Dolina oil and gas field with lithological column (source: Ascent Resources, Geomega 2012). Lendavska formacija je zgornjepanonijske do spodnjepontijske starosti. Zgornjepanonijske plasti sestavljajo srednje vezani drobno- do sre­dnjezrnati kremenovi pešcenjaki s sljudo in srednje trdi laporji, spodnjepontijske plasti pa sestavljajo slabo do srednje vezani kremenovi pešcenjaki s sljudo in srednje trdi laporji. Murska formacija je zgornjepontijske starosti in jo sestavljajo slabo vezani pešcenjaki, peski in prod ter pešcene in lapornate gline z vložki lig­nitnega do rjavega premoga (Markic et al., 2011). Kvartar sestavljajo gline, peski, prod in hu­mus. Serija pešcenjakov »Petišovci globoko« na naftno-plinskem polju Petišovci je s podrobno korelacijo EK-diagramov, jeder in podatkov, do­bljenih z geološko spremljavo vrtin, izdvojena v badenijskih in karpatijskih plasteh in sicer (od spodaj navzgor): serija F, serija E z nahajališci E4, E, E in E, serija D z nahajališci D in D, serija 32121 C, serija B z nahajališci B3, B2 in B1 ter serija A z nahajališci A4, A3, A2 in A1. Na osnovi korelacije EK-diagramov je ugoto­vljeno, da so serije F, C, B in A nasicene z vodo, oziroma vsebujejo le manjše kolicine plina. Se­rija E z nahajališci E, E, Ein Eje ugotovlje­ 432 1 na na celotnem polju. Nahajališci E3 in E2 sta zavodnjeni oziroma nasiceni z manjšimi koli­cinami plina. Dotok plina iz nahajališca E4 je bil ugotovljen samo v jugozahodnem delu polja v bloku 1 iz vrtin Pg-3 in Pg-6. Glavno nahaja­ lišce plina je E1, ki je najproduktivnejše v bloku 1 in v bloku 2. Serija D z nahajališci D1 in D2 se nahaja nad serijo E. Dotok plina iz nahajališca D1 je potrjen na vseh vrtinah. Najvecje kolicine plina iz nahajališca D so dobljene iz 2. bloka. Z dvema novima vrtinama, Pg-10 in Pg-11A pa se je izkazalo, da so perspektivna nahajališca še globlja od serije nahajališc F, to je vse do naha­jališc Q. Nahajališca K, L, M, N, O, P in Q (sl. 6) so vkljucena v proizvodnjo z vrtinama Pg-10 in Pg­-11A. V vrtini Pg-10 sta bili razkriti in mehan­sko obdelani nahajališci F in L, v vrtini Pg-11A pa M/N, O in P. Vsa našteta nahajališca so bila vkljucena v testno proizvodnjo leta 2011, v redno proizvodnjo pa so stopila leta 2017. Vsa nahajališca plina "Petišovci globoko" so slabo prepustni pešcenjaki miocenske starosti. Zaradi majhne primarne prepustnosti oziroma nizke permeabilnosti so bili omenjeni pešcenjaki v fazi proizvodne razdelave polja obdelani z me­hansko stimulacijo, ki je za polje Petišovci stan­dardni postopek za spodbujeno pridobivanje pli­na že vec kot šest desetletij (vir: Arhiv Petrol Geo). Fizikalne lastnosti kolektorskih kamnin nahajališc Izracun fizikalnih lastnosti kolektorskih ka­mnin nahajališc je bil narejen na podlagi podat­kov o poroznostih posameznih nahajališc (oglji­kovodikonosnih slojev), pridobljenih z analizo EK diagramov s programom EPILOG. Vrednosti glede nasicenja z vodo (Sw) zaradi vrste in last­nosti kamnin niso povsem zanesljive, kajti do­ bljene vrednosti so vecje od realnih. Laboratorijske vrednosti poroznosti in pre­pustnosti so bile izmerjene na sedmih odvzetih jedrih (Lisjak, 1988), na podlagi katerih se lahko poda verodostojno oceno kolektorskih parame­ trov. V tabeli 1 so prikazane vrednosti (povprecje med laboratorijskimi meritvami in vrednostmi, pridobljenimi iz EK diagramov) za poroznost, prepustnost in zasicenost s fluidi za nahajališca od D1 do E4. Fizikalne lastnosti za trenutno nova proizvodna nahajališca serije‚ 'K' (K-Q) navrta­ne na vrtini Pg-10 in Pg-11A niso podane zaradi zaupnosti podatkov, ki si jih pridržuje investitor. Klasifikacija in kategorizacija plinskega nahajališca Raziskovanje in izkorišcanje mineralnih suro­vin v R Sloveniji opredeljuje Zakon o rudarstvu (Uradni list RS, št. 14/2014). Po Pravilniku o kla­ sifikaciji in kategorizaciji zalog in virov nafte, kondenzata in naravnih plinov (Uradni list RS, št. 61/10), ki ga doloca Rudarski zakon, se morajo nahajališca v casu testiranja oziroma na zacet­ku redne proizvodnje ovrednotiti z elaboratom o zalogah. Šele na podlagi izdelanega elaborata se skupaj z rudarskim projektom za izkorišcanje mineralnih surovin na dolocenem pridobivalnem prostoru za doloceno obdobje dodeli koncesija s strani države Republike Slovenije. S klasifikacijo nahajališc opredelimo, ali gre za vire ali za zaloge, s stopnjo raziskanosti pa jih ovrednotimo v kategorije. Glede na ekonomsko terminologijo se zaloge nafte in plina delijo v tri skupine in sicer (Internet 2): -Geološke zaloge: so skupne ugotovljene ali ocenjene zaloge mineralnih surovin znotraj nahajališca ali rudnega telesa brez upošte­vanja odkopnih in industrijskih izgub. -Bilancne zaloge: so zaloge, ki se lahko pri obstojeci stopnji znanosti, tehnike, teh­nologije in ekonomike gospodarno izko­ rišcajo. -Izvenbilancne zaloge: so zaloge, ki se ne morejo po obstojeci stopnji znanosti in teh­nike ekonomicno izkorišcati. Tabela 1. Povprecne vrednosti za poroznost, prepustnost in nasicenost s fluidi v nahajališcih “Petišovci globoko” (po Lisjak, 1988). Table 1. Average values for porosity (.) water saturation (Sw), gas saturation (Sg) and permeability (k) of the »Petišovci globo­ ko« D and E reservoirs as analysed in the Pg wells (after Lisjak, 1988). Nahajališce / Reservoir POROZNOST / POROSITY NASICENOST S FLUIDI / FLUID SATURATION PREPUSTNOST / PERMEABILITY Vrtina / Well . Vrtina / Well Sw (voda) / Sw (water) Sg (plin) / Sg (gas) Vrtina / Well k (10-3 µm2) D1 Pg-2,5,6 0,081 Pg-5,6 0,40 0,60 Pg-5 0,38 D2 Pg-5,6 0,079 Pg-5,6 0,35 0,65 E1 Pg-2,3,5,6 0,091 Pg-5,6 0,35 0,65 Pg-3 8,6 E2 Pg-5,6 0,054 Pg-5,6 0,45 0,55 E3 Pg-3,5,6 0,065 Pg-5,6 0,45 0,55 Pg-5 0,27 E4 Pg-5,6 0,048 Pg-5,6 0,38 0,62 GEOLOŠKE ZALOGE / GEOLOGICAL RESERVES UGOTOVLJENE ZALOGE / IDENTIFIED RESERVES VIRI / SOURCES kategorije / categories kategorije / categories A B C(1) C(2) D(1) D(2) dokazane / raziskane / premalo raziskane / perspektivni / pricakovani / predpostavljeni / proven explored underexplored perspective expected assumed razredi / classes bilancne / balance izvenbilancne / off balance v izcrpanih ali opušcenih neizkoristljive v nahajališcih, v nahajališcih brez nahajališcih / kjer so bilancne zaloge / proizvodnje / in depleted or nonexploitable in production in production sites without abandoned production sites with balance reserves production sites Sl. 7. Klasifikacija in kategorizacija zalog in virov nafte, kondenzatov in naravnih plinov v Sloveniji (vir: Internet 3). Fig. 7. Classification and categorisation of reserves and resources of oil, condensates and natural gas as in use Slovenia (source: Internet 3). Racunsko se bilancne zaloge ovrednotijo po naslednji enacbi: BILA NCNE ZALOGE = GEOLOŠKE ZALOGE -IZVENBILANCNE ZALOGE Razvršcanje zalog in virov mineralnih suro­vin v ustrezne kategorije je pogojeno s stopnjo poznavanja (Inter net 2): -prostorska razporejenost kolektorja, -fizikalne lastnosti kolektorja, -fizikalne in kemicne lastnosti fluidov, -razmerja PVT fluidov, -proizvodne znacilnosti kolektorja. Ugotovljene in razvršcene zaloge ter viri mi­neralnih surovin (sl. 7) izražajo stopnjo njihove raziskanosti in pripravljenosti za nadaljnje izko­ rišcanje. Delijo se v (Internet 2): -A zaloge, ki se razvršcajo v nahajališcu ali delu nahajališca, ugotovljene z vrtinami z dotokom fluidov, dobljenim z osvajanjem vr­tin, ki so predvidene za proizvodnjo. Pri tem se ugotovi tudi: geološka sestava, oblika in velikost nahajališca ali njegovega dela, kol­ektorske lastnosti, položaj nahajališca ter fi zikalno-kemicne znacilnosti fluidov. -B zaloge, ki se razvršcajo v nahajališcu ali delu nahajališca, ugotovljene z nekaj vr­tinami, iz katerih je dobljen dotok fluidov z osvajanjem in potrjen s hidrodinamicni­mi meritvami ali s poskusno proizvodnjo. V drugih vrtinah je prisotnost fluidov ug­otovljena s karotažnimi meritvami, jeman­jem vzorcev jedra ali testiranjem med vr­tinami. Ugotovljena mora biti geološka sestava, oblika in velikost nahajališca ali njegovega dela, kolektorske lastnosti, raz­merja ter fi zikalne in kemijske znacilnosti fluidov. -C(1) zaloge, ki se razvršcajo v nahajališcu ali delu nahajališca, ki so odkrite z razisk­ovalnimi vrtinami. Dotok fluidov se doseže z osvajanjem in hidrodinamicnimi raziska­vami najmanj na eni raziskovalni vrtini. Meje nahajališca so dolocene na podlagi podatkov geološko-geofizikalnih raziskav in vr tanja. -C(2) vire, katerih prisotnost se pred­postavlja na podlagi podrobnih ge­ološko-geofizikalnih raziskav (razvoj strukturno-tektonske enote nahajališca). -D(1) vire, ki jih je mogoce pricakovati na podlagi rezultatov regionalnih geoloških in geofizikalnih raziskav (prisotnost nara­vnega rezervoarja, njegova strukturna ob­lika, prisotnost ogljikovodikov). -D(2) vire, ki jih je mogoce oceniti na pod­lagi temeljnih geoloških in geofi zikalnih raziskav. Za izracun zalog mineralnih surovin kategorij A, B in C(1) se uporabljajo naslednje metode: 1. prostorninska metoda, 2. metoda materialnega ravnovesja, 3. statisticna metoda, 4. metoda matematicnega modeliranja. Viri mineralnih surovin kategorije C(2) in D(1) se izracunavajo s prostorninsko metodo, viri ka­tegorije D(2) se izracunavajo po metodi geološke analogije. Pri elaboratu iz leta 1986 (Bokor et al, 1986) in leta 1988 (Lisjak et al., 1988) za izracun zacetnih geološki zalog in virov nafte, plina in kondenza­ ta na obmocju naftno-plinskega polja Petišovci- Dolina se je uporabila prostorninska metoda. Za­ loge in viri so bili izracunani po naslednji enacbi (sl. 8): A*h................ * Ø * ........................ ................ = ........................ -Gi - zacetne geološke rezerve (Sm3) / initial geological reserves (Sm3), -A - površina nahajališca (m2) / reservoir area (m2), -hef -povprecna efektivna debelina nahajal­išca (m) / average effective thickness of a reservoir (m), Sl. 8. Primer volumenskega preseka posameznega nahajališca „Petišovci globoko“ (Kercmar, 2014). Fig. 8. An example of a volumetric cross-section of a reservoir from “Petišovci globoko” (Kercmar, 2014). -ø - povprecna poroznost (v delih enote, ne %) / average porosity (in parts of the unit, not %), -Sgi - povprecno zacetno nasicenje s plinom (1-Swi) (v delih enote, ne %) / average initial gas saturation (1-Swi) (in parts of the unit, not %), -Bgi - zacetni prostorninski koeficient plina (m3/m3) / initial gas volume factor (m3/m3). Stopnja izkorišcenosti geoloških zalog (med­narodno znanih kot in-situ zalog) znaša za plin­ska nahajališca serije A-F »Petišovci globoko« 45 – 60 % (Bokor, 1986). Trenutno se v svetu za izracun zalog uporab­lja statisticna metoda, imenovana metoda Monte Carlo. Z omenjeno metodo se uporabijo vrednos­ti velikega številka meritev posameznih para­metrov (debelina plasti, poroznost, nasicenost z ogljikovodiki itd.), ki se nato prikažejo v verje­tnostni porazdelitveni frekvencni krivulji. Te se nato prevedejo v kumulativno krivuljo in nato odcitajo vrednosti P90, P50, P10 in mediana. Te vrednosti verjetnosti se potem uporabijo za izra­cun zalog s pomocjo površinske metode. V pri­meru ocene virov in zalog plina na obmocju Peti­šovcev z Monte-Carlo metodo je v smisel našega pravilnika o zalogah prevedel Markic (2014), kar je bilo predstavljeno tudi komisiji Komisiji za ugotavljanje zalog in virov mineralnih surovin januarja 2014. Proizvodnja plina iz nahajališc »Petišovci globoko« S Pg-vrtinami so bila raziskana plinska naha­jališc »Petišovci globoko«, iz katerih se crpata ze­meljski plin in plinski kondenzat vse od leta 1963 do danes. V casu raziskav in poizkusne proizvo­dnje je bilo ugotovljeno, da so plinska nahajališca Sl. 9. Proizvodnja plina in plinskega kondenzata po letih iz nahajališc »Petišovci globoko« serije A-F (vir: Petrol Geo, 2018). Fig. 9. Annual production of a gas and gas condensate from reservoirs »Petišovci globoko« series A-F (source: Petrol Geo, 2018). D, D, E, E, E in F proizvodna pod pogojem, 12134 da se poveca naravna propustnost z mehansko stimulacijo. Po izvedbi mehanske stimulacije je bila dalec najboljša proizvodnja dosežena iz na­hajališca E1. Takoj po stimulaciji nahajališc se vidi trend povecanja proizvodnje in sicer najvecja letna pro­izvodnja se je zgodila leta 1989, kjer so kolicine presegale 33 milijonov Sm3 in 2.000 m3 konden­zata. Skozi proizvodno obdobje nahajališca serije A-F je bilo narejenih 17 mehanski stimulacij od leta 1973 do 1994. Pet stimulacij je bilo narejeni leta 2011 na vrtini Pg-10 in Pg-11A za nahajali­šca serije‚ 'K' (K-Q). Skupno je bilo na naftno-plinskem polju Pe­tišovci iz plinskih nahajališc od zacetka proi­zvodnje leta 1963 do konca leta 2017 pridobljeno 341.754.115 Sm3 zemeljskega plina in 21.803 m3 kondenzata (Kraljic, 2015). Letne proizvodnje zemeljskega plina in kon­denzata od leta 1963 do 2017 iz nahajališc »Pe­tišovci globoko« serije A-F (D, D, E, E, E in 12134 F) so prikazane na sliki 9. Proizvodnja iz novih nahajališc serije K-Q na tej sliki še ni prikazana. Zakljucek Kljub temu, da se zdi proizvodnja zemeljske­ga plina pogosto samoumevna in enostavna, gre za celovit razvoj naftno-plinskega polja, se pra­vi vse od raziskav, nastanka, proizvodnje in na koncu tudi sanacije polja, kjer je vkljucena cela vrsta strokovnjakov, ki pokrivajo razlicne stro­ke za to dejavnost. V zadnjih letih so v Sloveniji dela potekala na perspektivnih nahajališcih ze­meljskega plina (»Petišovci-globoko«) na podla­gi najnovejših 3-D seizmicnih meritev. Uspešni rezultati se kažejo v proizvodnji plina iz seri­je‚'K' iz vrtin Pg-10 in Pg-11A. Pospešeno pa se proucujejo tudi možnosti pridobivanja ogljiko­vodikov, predvsem plina tudi v obmocjih drugih vrtin z možnostjo njihove poglobitve in iskanja naknadnih perspektivnih globokih nahajališcih. Dejstvo namrec je, da se z vecanjem globin raz­iskovanja in morebitnega pridobivanja plina vse bolj približujemo obmocju maticnih kamnin. S tem je pricakovati tudi vecjo vsebnost ogljikovo­dikov, predvsem plinonosnost kolektorskih ka­mnin obravnavanega obmocja. Zahvala Za dovoljenje in uporabo podatkov se zahvaljujem podjetju Ascent Resources plc. - Podružnica Lendava, za popravke in usmeritve pri pisanju clanka pa re­cenzentu dr. Milošu Markicu z Geološkega zavoda Slovenije. Literatura Bokor, N., Sacer, D., Bauk, A. & Secen, J. 1986: Elaborat o rezervama plina Petišovci­globoko, INA-Nafta Lendava: TOZD RNPN, OE Raziskave, Lendava. Cikeš, M. 2013: Proizvodnja nafte i plina. Rudar­ sko-geološko-naftni fakultet. Zagreb: 346 p. Djurasek, S. 1988: Pregledna karta podloge terci­jara sa odkrivenim naftnim i plinskim objek­tima. Nafta Lendava. Jahn, F., Cook, M. & Graham, M. 2003: Hydrocarbon Exploration and Production. Development in Petroleum Science 46. United Kingdom: 388 p. Jelen, B. & Rifelj, H. 2011: Površinska litostrati­g rafska in tektonska str uktur na kar ta obmo­cja T-JAM projekta, severovzhodna Slovenija = Surface lithostratigraphic and tectonic map of the T-JAM project area, northeastern Slovenia, 1: 100.000. Geološki zavod Slovenije, Ljubljana. Kercmar, J. 2014: Vtiskovanje slojne vode v Pt ležišca, Idejni projekt. Petrol Geoterm. Kraljic, M., Kercmar, J., Horn, B. & Lugomer-Pohajda, R. 2015: Rudarski projekt za izko­rišcanje nafte in plina na pridobivalnem pro­storu Petišovci-Dolina, št. proj.: RPZI, 02/15, PETROL GEOT ERM d.o.o., Lendava. Kraljic, M., Lisjak, L., Sovilj-Legcevic, J., Zag, J. & Levacic, N. 1997: Tehno-ekonomska ana­liza nadaljnje proizvodnje ogljikovodikov na naftno-plinskih poljih Petišovci in Dolina. Nafta Lendava. Sektor RPNP. Lendava: 39 p. Lisjak, L., Sovilj-Legcevic, J. & Bokor, N. 1988: Naftno-plinsko polje Petišovci, Elaborat o re­zervama nafte i plina, INA-Nafta Lendava: TOZD RNPN, OE Raziskave, Lendava. Markic, M. 2014: Ocena stanja zalog plina v peskih "A" do "Q" naftno-plinskega polja Petišovci na stanje 31. 12. 2012. Geološki zavod Slovenije, 20 p., dok.grad. 1-7. Markic, M., Turk, V., Kruk, B. & Šolar. V. S. 2011: Premog v Murski formaciji (pontij) med Lendavo in Murskim Središcem ter v širšem prostoru SV Slovenije. Geologija, 54/1:, 97­ 120. https://doi.org/10.5474/geologija.2011.008 Nerad, J. 2012: Energija v Sloveniji 2012. Republika Slovenija, Ministrstvo za infra­strukturo, Direktorat za energijo, Sektor za energetiko in rudarstvo: 54 p. Mioc, P. & Markovic, S. 1998: Osnovna geolo­ška karta. Tolmac za list Cakovec L 33-57. Inštitut za geologijo, geotehniko in geofiziko. Ljubljana, Inštitut za geološka istraživanja. Zagreb: 84 p. Nedeljkovic, V. 1963: Eksploatacija naftnih i gas­nih ležišta. Prvi deo. Tehnologija ležišta i proizvodnje. Novi Sad: 286 p. Pavšic, J. 2013: Geološki terminološki slovar. Založba ZRC, Ljubljana: 331 p. Plenicar, M. 1954: Obmurska naftna nahajališca. Geologija, 2: 36-93. Tanoh, A. D. 2016: The Exploration and Production Life cycle of oil and gas. http:// www. reportingoilandgas.org/the-explora­tion-a nd-production-l i fe -cycle -of-oi l-a nd­-gas/ (15.06.2018). Internetni viri: Internet 1: https://www.britannica.com/science/ gas-reser voir (15.06.2018). 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CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.012 Engineering-geological conditions of landslides above the settlement of Koroška Bela (NW Slovenia) Inženirskogeološke znacilnosti plazov v zaledju naselja Koroška Bela (SZ Slovenija) Tina PETERNEL, Jernej JEŽ, Blaž MILANIC, Anže MARKELJ & Mateja JEMEC AUFLIC Geološki zavod Slovenije, Dimiceva ulica 14, SI–1000 Ljubljana, Slovenija; e-mails: tina.peternel@geo-zs.si, jernej. jez@geo-zs.si, blaz.milanic@geo-zs.si, anze.markelj@geo-zs.si, mateja.jemec-auflic@geo-zs.si Prejeto / Received 10. 9. 2018; Sprejeto / Accepted 12. 12. 2018; Objavljeno na spletu / Published online 20. 12. 2018 Key words: landslide, debris flow, engineering-geological mapping, geotechnical monitoring, Urbas, Cikla, Bela stream, Koroška Bela Kljucne besede: plaz, drobirski tok, inženirskogeološko kartiranje, geotehnicni sistem za opazovanje, Urbas, Cikla, potok Bela, Koroška Bela Abstract This paper focuses on the studying of landslides in the hinterland area of the Koroška Bela settlement, NW Slovenia. Research has shown that these landslides have the potential to mobilize the material into a debris flow. The area of interest is located on the Karavanke mountain ridge, above the settlement of Koroška Bela, which lies on the outskirts of the town of Jesenice. In order to recognize and understand the kinematics of landslides and their triggering mechanisms, a multidisciplinary approach using engineering-geological and geotechnical investigations was applied. Thus, landslide source areas were determined based on engineering-geological mapping. Furthermore, landslide boundaries, types of landslides and sediments that are involved in processes of sliding were mapped in detail. Geotechnical monitoring is beneficial in evaluating rates of movement and failures in the ground under real conditions in the field. Current investigations as well as historical evidence and previous research prove that the hinterland of Koroška Bela is prone to various types of landslides that together form a source area that has the potential to mobilize into larger debris flow. Izvlecek Clanek se osredotoca na proucevanje plazov v zaledju naselja Koroška Bela v severozahodni Sloveniji, ki na podlagi dosedanjih raziskav predstavlja potencialno izvorno obmocje za nastanek drobirskih tokov. Obravnavano obmocje se nahaja v Zahodnih Karavankah nad vasjo Koroška Bela v bližini Jesenic. Za prepoznavanje in razumevanje kinematike plazov in njihovih sprožilnih dejavnikov smo aplicirali interdisciplinarni pristop, ki je obsegal inženirskogeološke in geotehnicne raziskave. Na podlagi inženirskogeološkega kartiranja smo dolocili izvorna obmocja plazov in njihov obseg, vrsto plazov in vrsto sedimenta, ki sestavlja plazeci material. Geotehnicni sistem za opazovanje je pripomogel k oceni velikosti premikov v samem telesu plazov pri realnih pogojih. Obsežne raziskave zaledja potoka Bela nad Koroško Belo so poleg zgodovinskih virov in preteklih raziskav potrdile domneve o dovzetnosti tega obmocja za nastajanje mastnih (drobirskih) tokov, kakor tudi zemeljskih plazov in skalnih podorov. Introduction The fact that Slovenia is highly susceptible to landslides underlines the need for the intensive study and monitoring of landslides in Slovenia, with the aim of defi ning prevention measures and mitigation measures in order to reduce the haz­ards associated with landslides. The past decade has seen four large landslides (Stože, Slano Blato, Strug and Kosec) with volumes of approximate­ly 1x106 m3 (Jemec Auflic et al., 2017). In the case of the Stože landslide that occurred in Novem­ ber 2000 above the village of Log pod Mangar­ tom in NW Slovenia and caused seven casualties and destroyed farm and residential buildings, the monitoring system consisted of 13 geodetic object points, 8 inclinometers for monitoring absolute displacements and streamflow measurements (Majes, 2001; Mikoš et al., 2006a; Cetina et al., 2006; Mikoš, 2011). In the same period, reactiva­tion of the Slano Blato landslide occurred above the village of Lokavec. The landslide was investi­gated using geophysical methods, geomechanical boreholes and engineering-geological mapping of the wider area (Majes et al., 2002; Ribicic & Kocevar, 2002; Logar et al., 2005; Fifer Bizjak & Zupancic, 2009; Mikoš et al., 2009; Macek et al., 2016). One year later, in 2001, the Strug landslide occurred above the village of Kosec. In that in­stance, the monitoring system consisted of peri­odical engineering-geological mapping, precipi­tation measurements, terrestrial laser scanning, geotechnical (inclinometers) and hydrological (piezometers) monitoring (Mikoš et al., 2005; Mikoš et al., 2006b; Mikoš et al., 2006c). This paper summarizes observation of the landslides above the settlement of Koroška Bela (NW Slovenia) using engineering-geological and geotechnical monitoring. Based on the previous investigation and given geological conditions and field surveys, the area of interest reflects num­ber of source areas that have the potential to mo­bilize the material there into a debris flow. The most active and characteristic are the Urbas and Cikla landslides (Jež et al., 2008; Peternel, 2017; Sodnik et al., 2017; Peternel et al., 2017a). Historical sources describe the broader area of Koroška Bela as known to have experienced several debris-flow events in the recent geologi­cal past. The most recent of these events occurred back in the 18th century and caused the partial or total destruction of more than 40 buildings and cultivated areas in a Koroška Bela village located in the area of the debris fan deposits (Lavtižar, 1897; Zupan, 1937). The first investigation and research of the Koroška Bela alluvial fan and its hinterland be­gan in 2006 within the Target Research Project (TRP): “Debris flow risk assessment in Slovenia”. Within the TRP project, the following activities were applied: geological mapping of the hinter­land of Koroška Bela (at scale 1: 5,000); and an investigation of alluvial fan deposits and debris flow modelling using the Flo-2D model. The thrust of the investigations indicated that the al­luvial fan is composed of a sequence of diamicton layers and related subaeric sediments that had been deposited by several debris flow events in the past (Mikoš et al., 2008; Jež et al., 2008). The first monitoring was established at the Urbas landslide using InSAR and GNSS technol­ogies. InSAR and GNSS results showed relative­ly large (up to 32 mm horizontal and up to 15 mm vertical) displacements over the course of the monitoring period of six months (feb.–aug./2011), indicating a displacement of the central-upper and south-eastern parts of the landslide body (Komac et al., 2012a; Komac et al., 2012b; Ko­mac et al., 2014). In order to evaluate the kinematics of Urbas landslide and also to understand the specifics of a sliding processes, to assess the sur ficial displace­ment rates and changes in the surface topography a periodical monitoring using tachymetric mea­surements, UAV photogrammetry, and terrestrial laser scanning (TLS) was applied (Peternel et al., 2017b; Peternel, 2017). Presently, some 2,200 inhabitants live in the area of the alluvial fan of past debris flows. With this risk potential in mind, monitoring the slid­ing mass and assessing the displaced material volumes is crucial, and more important than the purely scientific value of any assessment efforts (Peternel et al., 2017b). In this regard, the Koroška Bela hinterland was investigated using a combination of detailed engineering-geological mapping, together with geotechnical, geophysical and geodetic methods. With this paper we present the results obtained from the engineering-geological mapping and the geotechnical monitoring system using incli­nometer measurements for the Urbas and Cikla landslides. Site-specific geotechnical data is essential in evaluating movements and failures in the ground under real field conditions, and for the design and implementation of a monitoring system and ear­ly warning system for this large landslide. That data provides important information related to the characterization and strength of the geologi­cal structures involved and the kinematics of the unstable areas there. The most common geotechnical instrumenta­tion installed to monitor landslides consists in piezometers to measure groundwater levels and instruments like inclinometers to measure dis­placements. Slope inclinometers have been used to deter­mine the magnitude, rate, direction, depth, and type of landslide movement (Stark & Choi, 2008). This information is essential to understanding the cause and behaviour of landslides (Stark & Choi, 2008). Geological settings The broad area of the hinterland of Koroš­ka Bela exhibits fairly complex geological and tectonic conditions (fig. 1). Geological units of the study site are mainly represented by Upper Carboniferous and Permian sedimentary clas­tic rocks – Permian carbonates and Triassic to Lower Jurassic carbonate rocks (Jež et al. 2008). The main slope instabilities are related to tecton­ic contacts between the Upper Carboniferous to Fig. 1. Geological map and cross section of the hinterland of Koroška Bela. Permian clastic rocks (claystone, siltstone, sand­stone and conglomerate) and different Permian and Triassic carbonate and clastic rocks. The contact is represented by several reverse faults dipping approximately 70° to the NE (Jež et al., 2008). In terms of tectonics, the area is part of the Košuta fault zone and is dissected by numer­ous NW-SE faults linking two major fault zones (the Sava and Periadriatic fault zones) (Jež et al., 2008). Due to active tectonics the Upper Carbon­iferous and Permian clastic rocks are heavily de­formed, and, consequently, very prone to fast and deep weathering. Carbonate rocks in the upper­most parts of the Karavanke ridge are also sub­ject to physical and chemical weathering, result­ing in large quantities of talus and scree material covering the part lying below the clastic rocks. These landslide events are largely related to soft fi ne-g rained and tectonically defor med clas­tic rocks, most of which are covered with large quantities of carbonate scree material. Landslides descriptions The territory of interest is located in the Kar­avanke mountain ridge in north-western Slove­nia (46.26° N, 14.8° W), above the settlement of Koroška Bela that lies on the outskirts of the town Jesenice. The study area extends between an elevation of 600 m at the surface of the alluvial fan and 2100 m at the summit of peak Belšcica. The area is characterized by medium- to high-slope gradients ranging from 30° to 70°. It covers an area of approximately 6 km2 . The Karavanke mountain ridge is character­ised by an annual average precipitation of about 2600–3200 mm, distributed over 70–100 days. The study area has two precipitation peaks, with the main peak falling in autumn, and the second precipitation peak in spring. The lowest precipi­tation rate is recorded in summer (Internet). Due to its lithological and structural con­ditions and precipitation rates the area of the Koroška Bela hinterland is highly prone to land­ Fig. 2. Failure features on the surface: (a) Hummocky terrain with curved trees (b) Longitudinal tension cracks (c) Ponds on the surface (d) Subsidence of road slides. The upper part of the Urbas landslide at the main scarp and the part below are dominat­ed by rockslides and runoff of the scree materi­al. The main body of both landslides is formed by heavily deformed and weathered clastic rocks and is presumed to be a rotational deep-seated slow-motion slide that has accelerated predomi­nately with the percolation of surface and ground water (Jež et al. 2008; Komac et al. 2012). At the main body of the Cikla landslide a vast structure of carbonate rocks is also included, which locally disintegrate into a form of rockfall. The morphology of the entire hinterland of Koroška Bela is characterized by irregular and hummocky terrain comprised of protrusions and depressions of various sizes. Such activity is ev­idenced by “pistol butt” trees (fig. 2a), longitu­dinal tension cracks (fig. 2b), erosion slumps and ponds on the surface (fig. 2c), as well as the com­mon deformation of local roads (fig. 2d). A greater spatial density of springs and wet­lands is evident at the contact between scree and clastic rocks, partly supplied from the in­ filtration. Two of the most significant of these are the Urbas (1275 m.a.s.l) and Cikla springs (1190 m.a.s.l.). The monitoring sites are located at the Urbas and Cikla landslides, which are cur rently consid­ered to be the most active parts of the Bela stream hinterland based on previous investigations and field observations. The Urbas landslide is crossed by the Bela stream; meanwhile, the Cikla land­slide is crossed by the Cikla torrent, which is a tributary of the Bela stream. Both landslides have a gully-type morphology. The sliding mass is composed of tectonically deformed and weath­ered Upper Carboniferous and Permian clastic rocks covered with a large amount of talus mate­rial, which is prone to slope instability. Addition­ally, the Bela stream and its Cikla tributar y cause significant erosion and increase the possibility of the sliding mass mobilizing downstream. The ac­tive parts of the Urbas and Cikla landslides are characterized by bare ground with fallen trees, rugged surfaces, strong gully erosion and flank ridges. Methods In order to recognize and understand the landslides and their dynamics it is crucial to ap­ply an engineering-geological approach. It is also essential to set up a flexible and reliable monitor­ing system to monitor changes through time and space. Changes on the surface and observation of absolute displacements can be monitored using various surveying techniques. The Koroška Bela hinterland has been inves­tigated by combining detailed engineering-geo­logical mapping, geotechnical, geophysical and geodetic methods. This paper reports the results of engineering-geological mapping and geo­technical monitoring using inclinometer meas­urements. Hydrogeological investigations are represented in Janža et al., 2018. The spatial dis­tribution of all applied methods is shown in fig. 3. Fig. 3. Spatial distribution of applied methods (Peternel et al., 2017a). Landslide identification and mapping The field sur vey and the analyses of a 1-m grid digital elevation model (DEM) derived from lidar data were used for engineering-geological and geomor phological mapping. The entire hinterland of the Bela stream was geologically mapped at scale 1: 5,000, while se­lected important landslides were mapped at scale 1: 1,000. In the frame of detailed engineering-geolog­ical mapping the following features were deter­mined: landslide boundaries at the ground sur­face and landslide failure features on the surface (main and secondary scarps, shear zones, tension cracks, ponds, curved trees, deformation of local roads). Additionally, monitoring locations and related techniques (type of monitoring, data ac­quisition and locations) and geomechanical bore-holes were also defined. Geotechnical investigation An important part of the investigation of the Urbas and Cikla landslides involved the core drilling and core logging of 7 boreholes that was undertaken in September 2017. The locations for the boreholes were determined based on a field survey and logistical factors (accessibility of area) (fig. 3). Using the information provided by core log­ging allowed us to identify the main lithological units in the study area. Subsurface conditions, absolute displacement rates and measurements of ground water levels were interpreted on the basis of 4 boreholes equipped with inclinometers or piezometers (Table 1). Table 1. List of boreholes. Boreholes PP-4/17, PP-5/17 and CK-2/17 were equipped with inclinometers. Inclinometer mea­surements at PP-4/17 and PP-5/17 were taken using a Digitilt inclinometer probe with a mea­surement interval of 0.5 m. The full equipment consisted of the probe, a heavy-duty control ca­ble wound on a slip-ring reel, the DataMate II readout and DigiPro2 software. The PVC incli­nometer casings have longitudinal grooves in two perpendicular directions A and B (in which case direction A has to be determined south­ward) to ensure the probe remains oriented in the desired direction. The grooves of the guide casings were oriented in the expected direction of movement of the Urbas and Cikla landslides. The main purpose of employing inclinometer measurements was to determine absolute and displacement rates. The results are presented as displacement profiles (fig. 8), which are used to determine magnitude, depth, direction and rate of ground movement. Results Engineering-geological maps Based on engineering-geological mapping of the Bela stream hinterland at scale 1: 5,000, the most extensive and active landslides are the Ur­bas and Cikla landslides. In order to reconstruct the extension and kinematics, detailed mapping at scale 1: 1,000 was applied for both landslides. As a result, the Urbas and Cikla landslides were divided according to landslide prone areas (figs. 4, 5): Borehole Location GKX GKY Depth (m) Groundwater level * (m) Type of observation wall 1 PP-1/17 Urbas 433762 143830 40,0 7,80 none 2 PP-2/17 Urbas 433818 143766 29,0 11,2 none 3 PP-3/17 Urbas 433834 143692 31,0 21,30 none 4 PP-4/17 Urbas 433675 143735 33,0 3,70 Inclinometer PP-4 -Ppl/17 Urbas 433676 143737 15,0 3,1 Piezometer PP-4-Pgl/17 Urbas 433675 143736 6,0 3,2 Piezometer 5 PP-5/17 Urbas 433689 143717 40,0 8,8 Inclinometer (13 m) -destroyed 6 CK-1/17 Cikla 433059 144207 40,0 31,1 Piezometer 7 CK-2/17 Cikla 433027 144191 39,0 8,5 Inclinometer *groundwater level data were set after the drilling. Table 1 also shows data about groundwater level for each borehole. Groundwater level measurements were taken manually after the drilling. All information about hydrogeological investigations and groundwater dynamics are represented in Janža et al., 2018. -stable areas without clear landslide fea­tures, -potentially unstable areas with some land­slide and geomorphological features that indicate persisting sliding in the past or consist of soft sediments, -active areas that are characterized by nu­merous features that are the result of active landslide (e.g. bare ground, open cracks, tilted trees, etc.). The active part of the Urbas landslide (fig. 4) extends over an area measuring some 320 × 420 m and covers an area of approximately 85,320 m2 . The entire landslide including potentially unsta­ble areas measures up to 460 × 560 m. In the case of the Cikla landslide (fig. 5), the active area covers an area of 105 × 130 m, and is actively progressing toward NE, with a surface area extending over an area of approximately 8,000 m2 . Core logging The results of the core logging for the Urbas landslide are shown in figure 6. In borehole PP-1/17 a core was drilled up to 40.0 m. According to the detailed core logging of PP-1/17 three main lithological units were recog­nized. The uppermost layer (0 –7.8 m) is represent­ed by Quaternary Unit (Q) debris deposits that are composed of scree material (GW) and scree materi­al with clayey or/and silty binder (GC/GM). A low­ er depth (7.8–13.2 m), the silty and clay debris (ML, CL) prevail over talus debris. At a depth of 13.2 m the bedrock appears as grey, heavily deformed Up­per Carboniferous and Permian clastic rock. Three slip surfaces are presented in boreholes PP-1/17 at depths of 11.2, 13.2 and 15.0 m. The determined slip surfaces are related to wet segments, to con­tacts between soil and soft rock, and to a segment inside highly tectonized PC-siltstone. In borehole PP-2/17, the core was drilled down to 29.0 m. The upper layer (0–2.7 m) of PP-2/17 is represented by scree material containing silt and clay par ticles (GW/(CL/(GC)). This layer g radual­ly becomes a silt section with individual layers of silty gravel and silty sand (2.7–8.3 m). At a depth of 8.3 m, the section of grey, heavily-deformed Upper Carboniferous and Permian carbonate and clastic rock appears. Between 8.3 and 13.0 m the section is represented by limestone, sandstone and sandy marlstone. Fur ther dow n (13.0 –19.0 m) PP-2/17 is represented by a section of limestone that at a depth of 19 m becomes limestone brec­cia. In borehole PP-2/17 two slip surfaces were recognized at depths of 3.5 and 8.3 m. The first is related to a wet core segment, while the second represent the contact between soil and soft rock immediately above the bedrock. In the third borehole of PP-3/17, the total length of the core is 31.0 m. In the upper part it starts with a 3.9 m layer of Quaternary Unit (Q) debris deposits (GW). At a depth of 3.9 m the grey, completely weathered Upper Carboniferous and Permian clastic rock appears. From engineer­ing-geological point of view this layer can be classified as the residual soil (silt) of weathered PC siltstone without any recognizable structure. Three slip surfaces are presented at depths of 7.7, 12.5 and 15.7 m. The determined slip surfaces are related to segments inside completely weath­ered PC siltstone. In borehole PP-4/17, the core was drilled down to 33.0 m and was equipped with an inclinome­ter. The uppermost layer (0–3.80 m) is represent­ed by Quaternary Unit (Q) debris deposits that are composed of scree material (GW) and scree material with clay matrix. From 3.8 to 13.75 m Fig.6. Geotechnical borehole logs of the Urbas landslide. The locations of the boreholes are shown in fig. 3. the carbonate scree is mixed with clay debris (CL). At a depth of 13.75 m the bedrock appears as grey, heavily-deformed Upper Carboniferous and Permian clastic rock. In borehole PP-4/17 two slip surfaces were recognized at depths of 14.0 and 25.2 m. The first was recognized based on inclinometer measurements, while the second is related to a segment inside well-weathered PC-siltstone and a wet zone. In the fifth borehole of PP-5/17, the core was drilled to 40.0 m. The upper layer (0–16.0 m) of PP-5/17 is represented by alternating scree ma­terial (GW), scree material with silty binder (GM) and sand (SM), clay (CL) or silty (ML) de­bris. The bedrock appears at a depth of 16.0 m as a grey, heavily-deformed Upper Carboniferous and Permian clastic rock. Two slip surfaces are presented in PP-5/17 at depths of 15.0 and 25.4 m. The determined slip surfaces are related to wet segments, to contacts between soil and soft rock, and to a segment inside highly-weathered PC-siltstone. The area of the Cikla landslide was investi­gated through 2 boreholes. Borehole CK-1/17 was equipped with a piezometer, while CK-2/17 was equipped with an inclinometer. Both boreholes were drilled in area that was considered as po­tentially unstable areas in the immediate hinter­land of the currently active landslide (fig. 5). The results of core logging for the Cikla landslide are shown in figure 7. In borehole CK-1/17, the core was drilled down to 40.0 m and was equipped with a piezometer. Hydraulic conductivity of borehole sections and groundwater level fluctuations in CK-1/17 are presented in Janža et al., 2018. According to de­tailed core logging of CK-1/17, three main lith­ological units were recognized. The uppermost layer (0–29.5 m) is represented by Quaternary Unit (Q) debris deposits that are the consequence of fossil alluvial events. Deposits are composed of scree material (GW) with limestone blocks and scree material with silty binder. At a depth of 29.5 m the residual soil is composed of completely tec­tonized and weathered Upper Carboniferous and Lower Permian siltstone, with lenses of marlstone that gradually transit into massive siltstone. In the second borehole of CK-2/17, the total length of the core is 39.0 m. The uppermost lay­er (0– 4.9 m) some 4.9 m thick is composed of silty Fig. 7. Geotechnical borehole logs of the Cikla landslide. The locations of the boreholes are shown in fig. 3. clay (CL) and clayey gravel (GC) with a transition into silty sand (SM) and clay (CH). At a depth of 4.9 m to 8.9 m a layer of dolomite gravel and grav­el with clay matrix appears, followed by a section (8.9–11.8 m) of alternating layers (ML, CH, SM, GC). At a depth of 11.8 m a section (11.8–24.0 m) of completely tectonized and weathered Upper Carboniferous and Permian clastic rock appears. This layer is composed of alternation of gravel and clayey gravel with alternating layers (SM, CH, ML) followed by silty sand with gravel. At a depth of 24.0 m a grey, completely deformed Upper Car­boniferous and Lower Permian siltstone appears. Due to drilling, primary sedimentary structures of the rocks are largely unrecognizable in the core. Inclinometer measurements PP-4/17 and CK-2/17 were equipped with two inclinometers that reached down to significant depths (between 39 and 40 m) beyond the expect­ed slip surface (Table 1). The grooves of the incli­nometer (Aos, Bos) were oriented in the direction of the expected movement. Inclinometer monitor­ing was performed between September 2017 and May 2018. Until now, data has been collected for 3 observation periods for inclinometer PP-4/17, and for 2 observation periods for CK-2/17 (Table 2). The zero measurement at the inclinometer borehole PP-4/17 was taken on 28 September 2017. The zero measurement (for borehole CK­2/17) and the first reading (for borehole PP-4/17) Table 2. Observation periods of inclinometer monitoring. Observation period Date Length of observation period Inclinometer 1st 28 September – 12 October 2017 2 weeks PP-4/17 2nd 12 October – 27 October 2017 2 weeks PP-4 /17 +CK-2/17 3rd 27 October 2018 – 23 May 2018 7 months PP-4 /17 +CK-2/17 Fig. 8. Displacement measured by the incli­nometers installed at PP-4/17 (Urbas lands­ lide) and CK-2/17 (Cikla landslide). were performed on 12 October 2017. Follow-up measurements were performed on 27 October 2017, with the last on 24 May 2018 (Table 2). As the dates indicate, monitoring covered a period of 8 months. The displacement vertical profi les of the 2 inclinometer measurements at PP-4/17 and CK­2/17 are shown in figure 8. The inclinometer in­stalled in borehole PP-4/17 shows cumulative ab­solute displacements in the slope face direction of some 24 mm between October 2017 and May 2018 down to a depth of 14 m. Based on core logging the slip surface is related to heavily deformed Upper Carboniferous and Permian clastic rocks. The last measurement showed that the inclinom­eter installed in borehole PP-4/17 was cut at a depth of 14 m (fig. 8). Although that borehole CK-2/17 was locat­ed in the area that was considered as potential unstable area (approx. 15 m behind the crown crack of active landslide), inclinometer installed in borehole CK-2/17 showed significant displace­ments at a depth of 24 m. The measurements de­tect absolute cumulative displacements near 12 m over a period of 1 year (fig. 8). As in PP-4/17, the slip surface is related to heavily deformed Upper Carboniferous and Permian clastic rocks. Discussion This research focuses on the observation of large landslides that represent a direct risk to the settlement of Koroška Bela below. With this risk in mind a multidisciplinary monitoring approach was applied – specifically, slope mass instabili­ties were identified and investigated through detailed field investigations, including engineer­ing-geological mapping, geophysical investiga­tions and core logging of 7 boreholes (figs. 3, 6, 7). Applied surveys show that spatial distribution of the slope material and the relationships between lithological units are closely related to mass movement processes that have occurred in the past. The sliding mass is composed of tectonical­ly deformed and weathered Upper Carboniferous and Permian clastic rocks covered with a large amount of talus material that is prone to slope instability. The Urbas landslide spreads out over an area of nearly 90,000 m2 and was estimated to include up to 1 million m3 of sliding material. Sliding is expected to progress towards the north. The Cikla landslide, however, covers a significant­ly smaller area, but inclinometers indicate the sliding surface near the 25 m point. Additionally, in April 2017 a part of the Cikla landslide was transformed to debris-flow, which came to a halt about 500 m down from the Cikla stream. Addi­tionally, the Bela and Cikla streams causes sig­nificant erosion and contributes significantly to the mobilization of the sliding mass downstream. After Varnes (1978) classification and based on the determined depth of slip surfaces, both land­slides are understood to be deep-seated rotation­al slides. Additionally, two boreholes were equipped with pressure probes with recorders to observe fluctuations in groundwater levels. These obser­vations, which involved hydraulic tests, show complex and heterogeneous hydrogeological con­ditions predisposed by geological and tectonic settings and active mass movements that cannot be uniformly described (Janža et al., 2018). Conclusions In this study, the landslides above the settle­ment of Koroška Bela (NW Slovenia) were ob­served using engineering-geological mapping and through geotechnical investigations. By combining inclinometer data with core logging and engineering-geological surveys, the exten­sion and kinematics of relevant active move­ments were reconstructed. The presented study reveals that the Urbas and Cikla landslides are deep-seated landslides such as Macesnik land­slide (Pulko et al., 2014) and Rebernice landslide (Popit et al., 2017). Based on engineering-geolog­ical mapping and previous investigations the Ur­bas and Cikla landslides represent the most ac­tive landslides of the Bela stream hinterland. The Urbas landslide covers an area of approximately 85,320 m2, while the Cikla landslide extends over an area of approximately 8,000 m2 . Due to the geological and tectonic conditions of the study area, both landslides are prone to different land­slides: rockslides and runoff of scree material, deep-seated landsliding at the main body, and debris flow. Based on inclinometer readings, the Urbas landslide is moving at a maximum rate of down to a maximum depth of 14 m, while at the Cikla landslide significant displacements were registered at a depth of 22.5 m. This research finds and proves that mecha­nisms of landslides in the hinterland of the Koroš­ka Bela settlement are related to: (1) geological and tectonic conditions affecting rocks that are heavily deformed, and, consequently, ver y prone to fast and deep weathering, (2) surface and un­derground water circulation in the wider land­slides area and weak geomechanical properties of the lithological units of the study area. In the future, integration of the geomorpho­logical, geotechnical and geophysical informa­tion obtained, together with the monitoring data provided by the inclinometers installed there will provide particularly relevant information for a better understanding of the behaviour and kinematics of the studied instabilities. Further­more, this data represents input data that can be used in the 3D modelling of sliding surfaces and volume assessment, and in the planning of miti­gation measures and risk management strategies. In order to estimate the real effect of the tec­tonic, geological and meteorological conditions (e.g. amount of precipitation, snow melt, etc.) on the kinematics of landslides further, upgraded application of established monitoring (e.g. rain gauges, geotechnical sensors, etc.) is recommend­ed. 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Internet source: Internet: http://meteo.arso.gov.si/uploads/probase/ w w w/cli mate/image/sl/ by_var iable/precip­it at ion/mea n-a n nu a l-mea su r ed-pre cipit a­tion_81-10.png (15. 5. 2018) GEOLOGIJA 61/2, 191-203, Ljubljana 2018 © Author(s) 2018. CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.013 Hydrogeological investigation of landslides Urbas and Cikla above the settlement of Koroška Bela (NW Slovenia) Hidrogeološke raziskave plazov Urbas in Cikla nad naseljem Koroška Bela (SZ Slovenija) Mitja JANŽA, Luka SERIANZ, Dejan ŠRAM & Matjaž KLASINC Geološki zavod Slovenije, Dimiceva ulica 14, SI–1000 Ljubljana, Slovenija; e-mails: mitja.janza@geo-zs.si, luka.serianz@geo-zs.si, dejan.sram@geo-zs.si, matjaz.klasinc@geo-zs.si Prejeto / Received 15. 10. 2018; Sprejeto / Accepted 23. 11. 2018; Objavljeno na spletu / Published online 20. 12. 2018 Key words: landslide, groundwater, infiltrometer test, slug test, piezometer, Koroška Bela Kljucne besede: plaz, podzemna voda, infiltrometrski preizkus, nalivalni preizkus, opazovalna vrtina, Koroška Bela Abstract The area above the settlement of Koroška Bela is highly prone to slope mass movements and poses a high risk for the safety of the settlement. To get an insight into the hydrogeological conditions and processes which can affect mass movements in this area, hydrogeological investigations, including hydrogeological mapping, discharge measurements of springs, performance of infiltrometer and slug tests were performed. The results of these investigations show complex and heterogeneous hydrogeological conditions, predisposed by geological and tectonic setting and active mass movements which cannot be uniformly described. Observed large fluctuations in the rate of discharge of springs and groundwater level in observation wells are highly dependent on meteorological conditions. Estimated hydraulic conductivity of the soil is relatively high (2×10-4 m/s) and reflects the loose structure and high content of organic matter in the upper part of the forest soil. Hydraulic conductivity of more permeable sections of boreholes is in general higher in the upper parts, in predominantly gravel layers (in range from 2×10-3 to 1×10-5 m/s), than in the deeper clayey gravel parts (3×10-5 to 1×10-7 m/s). In the area of the Cikla landslide the average hydraulic conductivity is estimated at 8.99×10-4 m/s and is higher than in the area of the Urbas landslide (3.05×10-4 m/s). Izvlecek Na obmocju nad naseljem Koroška Bela je velika nevarnost nastanka pobocnih masnih premikov, kar predstavlja tveganje za varnost naselja. Za razumevanje hidrogeoloških pogojev in procesov, ki lahko vplivajo na masne premike na tem obmocju, so bile izvedene hidrogeološke raziskave, ki so vkljucevale hidrogeološko kartiranje, meritve pretokov izvirov ter izvedbo infiltrometrskih in nalivalnih preizkusov. Rezultati raziskav kažejo zapletene in heterogene hidrogeološke razmere, pogojene z geološkimi in tektonskimi znacilnostmi širšega obmocja ter aktivnimi masnimi premiki, ki jih ni mogoce enoznacno opisati. Opazovana velika nihanja pretokov izvirov in gladine podzemne vode v opazovalnih vrtinah so mocno odvisna od meteoroloških razmer. Ocenjeni koeficient prepustnosti tal je relativno visok (2×10-4 m/s) in odraža rahla tla z visoko vsebnostjo organske snovi, ki so znacilna za gozd. Koeficient prepustnosti bolje prepustnih odsekov vrtin je v splošnem višji v zgornjih delih, v plasteh s prevladujocim grušcem (v razponu med 2×10-3 in 1×10-5 m/s), kot v globljih delih vrtin, v zaglinjenih plasteh (med 3×10-5 in 1×10-7 m/s). Na obmocju plazu Cikla je ocenjen povprecni koeficient prepustnosti 8.99×10-4 m/s in je višji kot na obmocju plazu Urbas (3.05×10-4 m/s). Nomenclature v infiltration velocity (m/s) .V volume of infiltrated water during measuring phase when flow is close to steady-state con­ dition (m3) Ai area of inner infiltrometer ring (m2) t time (s) K hydraulic conductivity (m/s) i hydraulic gradient (-) z w saturated thickness trough which flow oc­ curs (underground depth of infiltrated water reach) (m) h hydraulic head (m) V total volume infiltrated over the entire dura­ tion of the infiltration test (m3) . volumetric water content - ratio of water vol­ume to total soil volume (-) . s saturated soil volumetric water content (-) .initial soil volumetric water content (-) .i. difference between . s and .i (-) A effective area of casing or excavation (m2) F shape factor (-) L length of effective intake or filtering zone (m) D diameter of effective intake or well point (m) Q injection rate (m3/s) m shape factor (-) r well screen radius (m) Introduction Hydrogeological conditions have an important role in the stability of slopes. Part of the rainfall that infi ltrates into the ground can contribute to the increase of pore pressures and saturation (de­crease of suction) of the ground or even to the rise of the groundwater table, all of which may ini­tiate mass movements on slopes. The changes of hydraulic conditions propagate from the ground surface into the subsoil and slope failures are more likely to take place a certain time after a rainfall event (Jemec Auflic et al., 2016; Nilsen et al., 1976). The time rate of propagation depends on the hydrogeological properties of the ground. The response of the slope material relies primar­ ily on the ground material; granular soils are more sensitive to short-duration intense rainfall events, whereas fine sediment (clay-like) materi­als are sensitive to long-duration and moderate intensity precipitation (Casagli et al., 2006). Beside the in-situ infiltration, the occurrence of groundwater that affects landslides can result from lateral flow, or ex fi ltration from the bedrock. Due to the unique groundwater flow pattern in every landslide, triggering mechanisms related to hydrogeolog y are complex ( Brönnimann, 2011). The local hydraulic field is related to the str ucture of the landslide mass, which is a result of land­slide activity, the formation of cracks, and in­creased hydraulic conductivity due to soil satura­tion. Therefore, the hydraulic conductivity of the landslide mass, which controls the groundwater flow, may be very heterogeneous (Guglielmi et al., 2002). The area of Koroška Bela settlement in NW Slovenia has experienced severe debris-flow events in the past and a big part of the settle­ment is even built on an alluvial fan of past de­bris flows (Jež et al., 2008). Due to the geological, tectonic and hydrogeological conditions, the area above the settlement is highly prone to different slope mass movements, posing a high risk for the safety of the settlement (Peternel et al., 2016). To assess the risk of mass movements and provide supportive information for the planning of safe­ty measures for the protection of the settlement, various series of geological (Jež et al., 2008), en­gineering (Peternel et al., 2018), geophysical, ge­omechanical, geomorphological, geodetic, and hydrogeological investigations were performed (Peternel et al., 2017). In this paper, hydrogeological investigations, which include hydrogeological mapping, dis­charge measurements of springs, performance of infiltrometer and slug tests in the period from 29 August to 26 October 2017 are presented. The aim of these investigations was to get an insight into the hydrogeological conditions and process­es which can affect mass movements in the area above Koroška Bela settlement. Study area The areas of the Urbas (85000 m2) and Cikla (8000 m2) landslides lie in the NW part of Slove­nia in the hinterland of the settlement Koroška Bela (figs. 1a, 1b). The areas of landslides extend from an elevation of 1150 m to 1300 m on the south to southwest oriented slope with gradient ranging generally from 30° to 70°. Average annual precipitation and temperature in this area range from 2000 mm to 2600 mm and from 3 °C to 5 °C respectively (ARSO, 2018a). The area is a part of the high east-west ex­tended mountainous ridge of Karavanke, a mountain range of the Eastern Alps. The terrain of the Karavanke Mountains consists of long and prominent ridges, whose slopes fall steep­ly to the northern and southern side. The ridges are interrupted by long, deep and narrow val­leys streams, exhibiting properties typical for high-mountain watercourses: ir regular and un­even channels with rapid flows (Brencic & Pol­tnig, 2008). Fig. 1a. Location of study areas. Regional hydrogeological setting In general, two types of aquifers characterize regional hydrogeological settings, intergranular and karst-fissured aquifers. Intergranular aqui­fers are presented by sediments formed as a con­sequence of intense slope processes typical for steeper mountain regions (slope sediments). In these sediments, groundwater may be retained, but their spatial extension is limited, and such aquifers mostly represent negligible groundwa­ter sources (Prestor et al., 2008). In some areas, groundwater can be found in sediments which were created by slowly slipping material formed by landslides, such as considered at the study area. In these cases, groundwater occurs at the contact between the above lying sloping sedi­ment and the underlying lower permeable bed- Fig. 1b. The areas of the Cikla and Urbas landslides with the locations of measurements and identified springs. rock. Within those layers, the groundwater flow is often interrupted by the presence of low per­ meable clay or mud material (Brencic & Poltnig, 2008). The karst-fissured aquifers are represented by carbonate rocks, which also for m the drain­age area of the investigated landslides. They are characterized by numerous karst springs of very diverse outflow regime. When consid­ering karst-fissured aquifers in the Karavanke Mts. area, it is necessary to also note the differ­ences in the hydrogeological characteristics of limestones and dolomites, which also influence the development of karst phenomena. The per­meability of dolomites comparing to limestone is usually lower. The hydrogeological proper­ties of dolomites depend also on the type of di­agenesis, or whether dolomites were formed as a result of primar y or secondar y dolomitization. Most karst-fissured aquifers in the Karavanke Mts. are unconfi ned, characterized by direct re­charge of in fi ltrated precipitation. In the South Karavanke Mts., springs occur at the (tectonic) contact of extensive aquifer with low permeable layers and represent the high-water overflow from this aquifer. The groundwater level with­in the karst-fissured aquifer is strongly relat­ed to precipitation and is highly variable. This is also reflected in the high discharge fluctua­tions of springs. In dry periods in summer, some springs can almost dry out, while in periods of intense rainfall they can reach discharges of a few 100 l/s (Brencic & Poltnig, 2008). Methods The field investigation in the two months pe­riod (29. 8. 2017 – 26. 10. 2017) started with the mapping of springs and other hydrogeological phenomena in the study area. Based on hydro-geological mapping locations of discharge meas­urements, new observation wells and in situ measurements of hydraulic conductivity were defined (fig. 1b). Discharges of Ui-1 and Ci-2 springs were es­timated with using bucket and a stopwatch. The flows of other springs could not be collected in a bucket; therefore discharges were only visual­ly estimated. Field measurements of pH value, electrical conductivity and temperature (Table 1) were carried out with measuring instrument pH/ Cond 340i, and measurements of ORP (Oxydation Reduction Potential) and dissolved oxygen with instrument Multi 3410 SET C, both products of the WTW company. In situ measurements of hydraulic conductivity Infiltrometer tests Infiltrometer tests enable the estimation of infiltration rate (infiltration capacity) as the maximum rate at which soil will absorb water impounded on the surface at a shallow depth, when adequate precautions are taken regarding boundary effects (Richards, 1952; Johnson, 1963). In the study area, a double ring in fi ltrometer was used which creates vertical (one-dimensional) flow of water beneath the inner ring and simpli­fies interpretation of measurements (Köhne et al. 2011) (fig. 2a). The method is based on the Darcy law of groundwater flow through intergranular porous material at steady state conditions (con­stant-head and constant infi ltration velocity). The volume of water used during each measured time interval was converted into the incremental infiltration velocity using the equation (EN ISO 22282-5-2012, 2012): .V v = At i. from Darcy law follows: v = Ki hydraulic gradient can be approximated as: zw + hii = zw saturated thickness (z w) through which flow occurs can be determined as: V zw = Ai.. where .. is difference between the saturated soil volumetric water content (.s) and the initial soil volumetric water content (.i). To assure horizontal surface and avoid surface cracks and fissures, typical for landslide mass, infiltrometer tests were performed at two loca­tions close to the boundary of the Urbas landslide (fig. 1b), which could be accessed by car and sup­plied with the required amount of water. At these locations is present a soil typical for coniferous forest which covers a large part of the study area (fig. 2b). The rings were inserted into the ground to a penetration depth of 0.05 m and a constant-head was maintained in both rings (hi=0.05 m) with the supply of water with Mariotte’s bottle (fig. 2a). The tests were performed on 26. 10. 2017, three days after a moderate rainfall event. Fig. 2a. Double ring infiltrometer with Mariotte’s bottle (photo: Zmago Bole). Falling and constant-head tests The constant and falling-head tests in the cased boreholes or trial pits are commonly-used field methods for estimating the hydraulic con­ductivity of porous material. The review of ex­isting practical engineering procedures for the performance of constant and falling-head tests was presented by Brencic (2011), while the the­oretical background can be found in literature on hydraulic tests (e.g., Batu, 1998; Butler, 1998; Bouwer & Rice, 1976; Cedergren, 1989; Kruse­man & De Ridder, 1990). Falling-head tests The widely used interpretation of falling-head tests is the Hvorslev method (Hvorslev, 1951), be­cause it provides a quick and inexpensive proce­dure for obtaining a relatively reliable estimation of hydraulic conductivity from a single well. This method is based on the interpretation of hydrau­lic head changes in time and is suitable for wells that are open in a short section at their base. Hvorslev (1951) found out that the return of the hydraulic head to the original, static hydraulic head occurs at an exponential rate with the time and is dependent on the hydraulic conductivity of the porous material. The Hvorslev method is valid for confined aquifers. However, Bouwer (1989) observed that the water table boundary in an un­confi ned aquifer has little effect on test perfor­mance results, unless the top of the well screen is positioned close to the water table. Therefore, in many cases, we may apply the Hvorslev solution for confined aquifers to approximate unconfined conditions. The basic equation for unsteady con­ditions is as follows (Hvorslev, 1951): A h1 K= ×ln tF h2 .× where the shape factor F is expressed as: 2p×L F= .2L. ln . . .D. or when the water flow is limited on ly th rough well walls: 2pL F= 2.75D .2L. ln . . .D. or when the water flow is limited only on the bottom of tube: F=2.75D Hvorslev method (Hvorslev, 1951) is valid only if the length of the well screen is more than 8 times larger than its radius (L/r >8). The tran­sient solution omits storativity of the formation and assumes a quasi-steady-state flow between the control well and the tested formation. The following assumptions should be applied to the use of the Hvorslev method: the aquifer has in­finite areal extent; the aquifer is homogeneous and of uniform thickness; the aquifer potentio­metric surface is initially horizontal; a volume of water is injected or discharged instantaneously (Hvorslev, 1951). The second method used in this investigation was proposed by Schneebeli (1987). This method shows the same results as the Hvorslev method, if small diameter wells (negligible well storage) are used. In the case of large diameter wells or objects (i.e., excavated trail pit), the results of the methods differ, since the way that the geometric shape factor in Schneebeli’s equation is deter­mined is more robust and its value is proportion­al to the geometry of the tested object. The shape factor suits the recharge with semiellipsoidal shape (Dachler, 1936; Hvorslev, 1951). Schneebeli (1987) suggested the equation as follows: . . h1 log . . h2 . . K mA 2.3 =·· · tt 1 -2 where m represents a geometric shape factor: a m= D and a is expressed as: . 2 . L L . . ln . +1. . .+ .D . . D . . . a= L . . 2 p . . D . . However, it should be noted that there are some other limitations that affect the reliability of falling-head tests in large diameter wells or objects. For example, the hydraulic conductivity of the material should not be high, or the changes of hydraulic head should be fast, and in large di­ameter wells the capacity effect can greatly slow down the reduction of hydraulic head (Mace, 1999). Constant-head test The constant-head test is based on steady state conditions, where the hydraulic head in the borehole is stabilized with a constant water in­jection. The stabilized hydraulic head reached in a borehole or other tested object in which a con­stant injection is given by the following expres­sion (Custodio & Llamas, 1983): Qh= FK where F is a shape factor of tested object and is expressed as: 2pL F= L ln r obtains the hydraulic conductivity as follows: Q L K= ln 2pLh r Application of hydraulic conductivity measurements in the field Falling-head and constant-head test were performed in three different types of hydrogeo­logical objects: trial pits, open-bottom tubes, and boreholes. In all objects, the water level was mea­sured with a pressure probe (PPI 200) with data Fig. 3. Trial pit for performing falling-head test (photo: Zmago Bole). From the test conditions and the injection rate Fig. 4. Open-bottom tubes for performing falling-head test to stabilize water level, the application directly (photo: Zmago Bole). Fig. 5. An example of falling-head test performed in the well (PP-4/17). logger (GSR 120NTG), produced by the Eltratec company. The pressure probe measures to an ac­curacy of 1 to 10 mm and in a range from 0 to 30 m of water column. Each test was carried out within specific field conditions; therefore the in­jection rate and duration were different for each individual tested object. Water level measure­ments were recorded at 5 to 10 s inter vals. Falling-head tests in trial pits were carried out in rectangular-shaped excavations made with a digger (fig. 3). Falling-head tests in open-bot­tom tubes were carried out with a tube (internal diameter of 100 mm), inserted into the ground surface or bottom of trial pit. The J-Urbas tri­al pit was 2.7 m deep. In the deepest part, it was 1.5 m long and 0.6 m wide (fig. 3). In its upper part, two shelfs were made, at the depths 2.0 and 0.6 m. On the upper shelf, an open-bottom tube test was performed (fig. 4). Tests at this location were made on 8. 9. 2017. The J-Cikla trial pit was 2.4 m deep, 1.6 m long and 0.6 m wide. Near the trial pit, two open-bottom tube tests were performed (Table 3). In both locations, the upper soil was removed, in the first location down to 0.4 m (Tube-1) and in the second location down to 0.2 m (Tube-2). Tests at this location were made on 18. 9. 2017. The borehole falling-head test was performed on more permeable sections of boreholes, which were determined on the basis of lithological bore-hole logs (Peternel et al., 2017). On these sections, drilling with a core drill was carried out after the completion of the technical column. Measure­ments were performed in 1 – 2 m open hole sec­tions. Before the test started, the occurrence of groundwater was checked. At locations where we could provide enough water, the performance of falling-head test was carried out in two steps. The second step or sec­ond injection was performed after the stabiliza­tion of the water level in previous step. Moreover, at suitable borehole sections we also performed a constant-head test. In the study area, the most permeable layers are presented in the form of several-metre-thick coarse (gravel) sediments. In most cases, the tested borehole section included different types of lithology. The common exam­ple of the falling-head test performance is shown in the fig.5. The example shows that in the up­per 0.7 m of the borehole, in the gravel layers, the drawdown is rapid, while in the lower part, in clayey material, drawdown is significantly slow­er. In such cases, two different lines were used to interpret the slope of the curve, for the purposes of the processing and estimation of the coef ficient of hydraulic conductivity. Results In the area of Urbas landslide, seven perma­nent springs were identified and one in the broad­er area of Cikla landslide, beside permanent springs several temporal springs were observed (fig. 1b). Spring Urbas (Ui-1) is captured for the water supply of nearby mountain huts Potoška planina and Valvasorjev dom pod Stolom. Dis­charge measurements during the field campaign show a large fluctuation of discharge, from up to 25 l/s shortly after rainfall, to very low or even no discharge in dry conditions (figs. 6a and 6b). Basic water parameters measured at permanent springs on 29. 8. 2018 are presented in Table 1. Fig. 6. a) Precipitation measured at meteorological station Planina pod Golico (ARSO, 2018b), b) Observed discharge at sprin­gs, c) Groundwater levels in well PP-2/17, d) Groundwater levels in wells PP-4/17 (circles) and PP-5/17 (squars). Occasional manual measurements of ground-Hydraulic conductivity of upper ground, es­water level during the field campaign were per-timated with falling-head tests in trial pit and formed in 7 boreholes (Peternel et al., 2017, fig. open-bottom tube is presented in Table 3. In the 6c). After the field campaign, continuous mea-area of landslide Urbas hydraulic conductivity of surements with a pressure probe were recorded upper silted gravel layers is in the range between in wells PP-4/17 and CK-1/17 (fig. 7). 1.65×10-5 m/s and 1.96×10-5 m/s (avg. 1.8×10-5 m/s). Results of two infiltrometer tests performed Similar values with an average of 3.24×10-5 m/s in the study area (fig. 1b) are summarized in Ta-were estimated for upper clayey sandy layers ble 2. with gravel at Cikla location. Table 1. Basic water parameters: pH, electrical conductivity (EC), temperature (T), dissolved oxygen (DO), redox potential (Eh), and discharge (Q), measured at permanent springs on 29.8.2018. Spring Elevation (m a.s.l.) pH EC (µS/cm) T (oC) DO (mg/l) Eh (mV) Q (l/s) Ui-1 1267 8.3 186 4.0 11.9 434 1.0 Ui-2 1260 8.5 240 11.1 10.1 417 0.3 Ui-4 1233 7.7 226 5.9 10.4 506 0.2 Ui-5 1242 7.8 228 6.8 10.6 469 0.1 Ui-6 1237 7.7 234 6.1 10.6 515 0.1 Ui-7 1199 7.8 255 8.0 10.4 435 0.1 Ui-9 1176 8.0 228 5.7 11.1 441 0.5 Ci-2 1027 8.2 290 6.8 11.3 393 4.0 Mean 1205 8.0 236 6.8 10.8 451 0.3 Range 240 0.8 104 7.1 1.8 122 3.9 Table 2. Results of infi ltrometer tests. Parameter INF-1 INF-2 .t (s) 1007 664 .V (m3) 0.017 0.015 .(-) 0.2 0.2 V (m3) 0.022 0.026 z w (m) 1.43 1.40 K(m/s) 2.10×10-4 2.81×10-4 Table 3. Hydraulic conductivity of upper ground, estimated with falling-head tests in trial pit and open-bottom tube. Location Soil type Classification symbol Testing object Pouring water step Unsteady K m/s -Hvorslev Unsteady K m/s -Schneebeli J-Urbas Silted gravel GM Trial pit / 1.96×10-05 Tube 1.65×10-05 / J-Cikla Clayey sandy silt with gravel ML/GC Trial pit / 2.91×10-05 Near J-Cikla Tube-1 1. 2.55×10-05 / 2. 5.74×10-05 / Tube-2 1. 2.72×10-05 / 2. 2.30×10-05 / Hydraulic conductivities of more permeable sections of boreholes CK-1/17 and PP-4/17 (fig. 8), estimated with performance of falling-head and constant-head tests in boreholes are presented in Table 4 and Table 5. Estimated hydraulic conductivities in well CK-1/17 range between 2.64×10-3 and 7.78×10 -6 m/s. The Hvorslev and Schneebeli methods give practically identical results. The average value calculated for all three tested depth using only results of Hvorslev (or Schnee­beli) and steady state method is 8.99×10-4 . In well PP-4/17 values of hydraulic conductivities ranges between 1.67×10-3 and 1.02×10 -7 m/s. The average value calculated for all five tested depth intervals using results of Hvorslev (or Schnee­beli) and steady state method is 3.05×10-4 m/s. Fig. 7. a) Precipitation measured at meteorological station Planina pod Golico (ARSO, 2018b) in comparison with b) Groundwater level fluctuation in wells PP-4/17 (solid line) and CK-1/17 (dotted line). Fig. 8. Simplified lithological profiles of piezometers CK-1/17 and PP-4/17 (segment with blue colour represents the perforated area). Table 4. Estimated hydraulic conductivity of three sections in well CK-1/17. Tested section m Soil type Classification symbol Injection step Interpreted line slope Unsteady K m/s ­Hvorslev Unsteady K m/s ­Schneebeli Steady K m/s 13.00 – 14.12 Silted gravel GW – GM 1. 2.17×10-3 2.17×10-3 9.14×10-4 2. 2.64×10-3 2.64×10-3 / 19.50 – 20.28 Clayey sandy silt with gravel GM - GW 1. 1. 7.83×10-4 7.83×10-4 / 2. 2.39×10-4 2.39×10-4 / 2. 1. 1.25×10-3 1.25×10-3 / 2. 6.20×10-5 6.21×10-5 / 28.70 – 30.25 Silted gravel GM 1. 1. 3.23×10-5 3.23×10-5 / 2. 7.47×10-6 7.46×10-6 / 2. 2.57×10-5 2.56×10-5 / Table 5. Estimated hydraulic conductivity of four sections of borehole PP-4/17. Tested section m Soil type Classification symbol Injection step Interpreted line slope Unsteady K m/s -Hvorslev Unsteady K m/s -Schneebeli Steady K m/s 1.07 - 2.52 Gravel with clay and sand in lower part GW-GC 1. 1. 3.36×10-4 3.36×10-4 5.40×10-4 2. 1.15×10-5 1.15×10-5 2. 1. 4.46×10-4 4.46×10-4 / 2. 6.68×10-6 6.68×10-6 / 2.70 - 3.87 Gravel with sand and silt CL/GC 1. 1. 1.67×10-3 1.67×10-3 5.72×10-4 2. 5.18×10-4 5.18×10-4 / 6.55 - 7.88 Gravel with gravel clay CL/GW 1. / / 3.32×10-4 2. / / 3.37×10-4 9.00 - 10.70 Clayey gravel with sand CL/GW 1. 8.10×10-6 8.09×10-6 / 12.6 - 15.17 Weathered siltstone SOFTROCK 1. 1.02×10-7 1.02×10-7 / Discussion The observed large fluctuation of discharge of springs and occasional dr y outs are highly dependent on meteorological conditions, which reflects the low storage capacity of aquifers or locally limited recharge areas of the springs. A strong relation between meteorological and groundwater conditions is reflected also in the groundwater level fluctuation, obser ved in the wells. The fast rise of groundwater level after rainfall is observed in all wells, however, the amplitudes of fluctuation differ (figs. 6 and 7). The largest amplitude (12 m) was observed in the well PP-2/17. At this location, low permeable permo-carboniferous layer overlay the aquifer which consists of marly limestone and breccia. It seems that the aquifer is a part of an aquifer system that has a large catchment and is partly drained out at the Urbas spring. Due to the low permeable upper layer, semi confi ned conditions are created. Also continuous measurements of groundwa­ ter level fluctuation in wells CK-1/17 and PP-4/17 show fast changes of groundwater level which are strongly related to precipitation (fig. 7). Ampli­tudes are higher, up to 6 m, in well CK-1/17 than in well PP-4/17, where the maximum amplitude of groundwater level is below 2 m. These differ­ences could be attributed to the higher hydraulic conductivity, larger thickness (Table 4 and Table 5), and probably also larger spatial extent of more permeable layers at location of well CK-1/17. The results of infiltrometer tests show rel­atively high hydraulic conductivity of the soil. Presumably, this reflects the loose structure and high content of organic matter in the top soil found in the forest which covers a big part of the study area (fig. 2b). The tests were performed at locations where the ground has not been de­formed by mass movement. Due to the presence of cracks and fissures, locally higher infiltration could be expected in the landslide body. The planning of the falling-head test in wells assumed that significant groundwater flow can be established only through more permeable lay­ers. Consequently, falling-head test were per­formed in more permeable gravel sections of boreholes. Therefore, calculated hydraulic con­ ductivities reflect properties of more permeable parts of the ground in the study area. In gener­al, higher hydraulic conductivity is observed in the upper parts of the boreholes. Those layers are predominantly represented by gravel and have a medium hydraulic conductivity, while the lower clayey gravel parts have a low hydraulic conduc­ tivity. In the area of Cikla landslide, values of hydraulic conductivities were estimated approx­imately half order of magnitude higher than in the Urbas landslide. The differences in hydraulic conductivities could be attributed to the litholog­ical composition of the ground, which, in general, shows a larger share of course material in upper parts of the ground and in the area of Cikla land­slide. The groundwater occurrence was identi fied in the last tested interval (28.70–30.25 m), while the first two tested intervals were in an unsatu­rated zone. In borehole PP-4/17 all tested inter­vals were in a saturated zone. Conclusions The observations and hydraulic tests per- for med in the area above Koroška Bela settlement have shown complex and heterogeneous hydro-geological conditions, predisposed by geological and tectonic setting and active mass movements. Therefore, the observed hydrogeological environ­ ment cannot be unifor mly defi ned. To adequately address such conditions, an approach is required which combines various hydrogeological meth­ods, partly already performed in the presented study. The performed investigations enabled a very rough insight into the landslide hydrogeological mechanism and provided the fi rst data on the hy­draulic conductivity of the material in the land­slide masses, the groundwater level, the infiltra­tion capacity of the ground, the occurrences of the springs and their discharges. However, still many uncertainties exist about the hydrological processes occurring in observed landslides. In order to evaluate the role of groundwater and hy­drogeological processes on landslides movements continuation of hydrogeological monitoring (groundwater level and temperature measure­ments) and additional investigations (e.g., hy­drogeochemical and isotope analysis) for better defi ning recharge mechanism and groundwater flow patterns in the landslide bodies and their catchment areas are proposed. Acknowledgements The investigations presented in this study were conducted in the frame of a project financed by the Ministry of the Environment and Spatial Planning and supported by the Slovenian Research Agency (ARRS) through research project (grant. no. J1-8153) and the research programme Groundwaters and Geochemistry (P1-0020). The authors would like to thank Zmago Bole for his contribution in the field work and two anonymous reviewers for constructive reviews. References ARSO 2018a: Environmental atlas of Slovenija. Slovenian Environment Agency. Internet: http://gis.arso.gov.si/atlasokolja (6. 11. 2018) ARSO 2018b: Archive of weather observations. Slovenian Environment Agency. Internet: http://meteo.arso.gov.si (30. 5. 2018) Batu, V. 1998. Aquifer Hydraulics: A Comprehensive Guide to Hydrogeologic Data Analysis. John & Wiley & Sons, New York: 752 p. Bouwer, H. 1989: The Bouwer and Rice Slug Test - An Update. Groundwater, 27: 304-309. 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CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.014 Comparison of the fully penetrating well drawdown in leaky aquifers between finite and infinite radius of influence under steady-state pumping conditions Primerjava znižanja gladine podzemne vode v hidravlicno popolnem vodnjaku v polzaprtem vodonosniku med koncnim in neskoncnim radijem vpliva pri stacionarnem crpanju Mihael BRENCIC Department of Geology, Natural Sciences Faculty, University of Ljubljana, Aškerceva cesta 12, SI-1000 Ljubljana; e-mail: mihael.brencic@ntf.uni-lj.si Geological Survey of Slovenia, Dimiceva ulica 14, SI-1000 Ljubljana Prejeto / Received 11. 6. 2018; Sprejeto / Accepted 28. 11. 2018; Objavljeno na spletu / Published online 20. 12. 2018 Key words: leaky aquifer, groundwater drawdown, relative difference, absolute difference, modified Bessel functions of zero order, Hantush integral Kljucne besede: polzaprt vodonosnik, znižanje podzemne vode, relativna razlika, absolutna razlika, modificirana Besselova funkcija nicelnega reda, Hantushev integral Abstract In the paper theoretical derivation of steady state groundwater well pumping from leaky aquifers with infinite and finite radius of influence are presented. Based on the extensive literature review following mainly Jacob and Hantush work equations were derived from the cylindrical Bessel partial differential equation and results expressed in the combination of modified Bessel functions of zero order of the first and the second kind (I0, K0). We have shown that equation for steady state well pumping in the infinite aquifer is infinite limit of Hantush integral. Mathematical characteristics of solutions for infinite and finite radius of well influence were combined in the way that they can be represented as relative and absolute differences of drawdowns of each model. In the case when available data do not allow us to make a decision on the type of the radius of influence of the pumping well, they can help us in the interpretation of various errors due to application of different analytical models of pumping test. Izvlecek V clanku je prikazana izpeljava enacb crpanja podzemne vode iz vodnjaka v polzaprtem vodonosniku pri stacionarnih pogojih za primer koncnega in neskoncnega radija vpliva. Na podlagi obsežnega pregleda literature, ki izhaja predvsem iz del Jacoba in Hantusha, smo iz cilindricne Besselove parcialne differencialne enacbe izpeljali izraze za znižanje podzemne vode, ki predstavljajo kombinacijo modificiranih Besselovih funkcij nicelnega reda prve in druge vrste (I0, K0). Pokazali smo, da je enacba stacionarnega crpanja iz neskoncnega vodonosnika neskoncna limita Hantushevega integrala. Matematicne znacilnosti rešitve za neskoncni in koncni radij vpliva crpalnega vodnjaka omogocajo, da izraze združimo tako, da lahko prikažemo relativne in absolutne razlike med obema rešitvama. V primeru, da zaradi pomanjkanja podatkov ne moremo sprejeti odlocitve o tem, s kakšnim radijem vpliva imamo opraviti, nam te razlike omogocajo interpretacijo razlicnih napak izbranih analiticnih modelov. Introduction aquifer water balance and groundwater chemical The most important and reliable in situ meth­ status. These are reasons why pumping tests and ods for groundwater investigations are pumping the theory which connected with them is central tests. During them water is pumped from the well to the hydrogeological science. The theory of constructed in the soil or rock and groundwater pumping test is well developed and very complex. drawdown in the surrounding of the pumping Since the very beginning when Theis published well is observed. Pumping tests are intended for fi rst mathematical model for unsteady ground- determination of aquifer physical characteristics, water flow toward the well (Theis, 1935) many conceptual and mathematical models of pump­ ing tests were developed (for the review see Batu, 1998; Lebbe, 1999; Yeh & Chang, 2013 and refer­ences there in). The appearance of water in intergranular po­rosity is conceptualized with the aquifer model which usually consists of three main elements: saturated part, unsaturated part and hydrogeo­logical barriers. Different combinations of these elements represent different hydrodynamical models of aquifers. In general, we are talking about two main hydrodynamical types of aqui­fers with transitions between them. The simplest one is confined aquifer where saturated part is confined between two impermeable hydrogeo­logical barriers. The other main aquifer type is unconfined aquifer where groundwater level fluctuates depending on the recharge. In natural conditions aquifers are complex entities consist­ing of beds with very different geometries and hydraulic characteristics. Aquifers where sever­al beds with different hydraulic characteristics and contrasts are present are often conceptual­ised as leaky aquifers. In real aquifers drawdown of groundwater level during the pumping test or full well operation is complex. The very fi rst study on leaky aquifers under steady-state groundwater flow was presented by De Glee (1930). Jacob (1946) extended the work on leaky aquifers by introducing transient effect of leakage. In his treatment the key assumption was that the vertical flow rate in the upper hy­drogeological barrier defined as an aquitard is proportional to the drawdown distribution in the same bed. Later Hantush and Jacob (1955) and Hantush (1959) derived analytical solutions for unsteady-state groundwater flow in leaky aqui­fer for fully penetrating well of infinitely small diameter. In addition, Hantush (1960, 1964) and DeWiest (1965) assumed that the piezometric head in the aquitard overlying permeable part of the aquifer does not change during water withdraw­al from the underlying pumped part. The valid­ity of the assumption that Darcian groundwater flow in the permeable pumped part of the aqui­fer is horizontal and in the overlying aquitard is vertical was tested by Neuman and Witherspoon (1969). The errors introduced by this assumption are less than 5 % if the difference in permeabili­ty between confined bed and semiconfining beds is of at least two orders of magnitude. Herrea and Figueroa (1969) and Herrea (1970) presented a correspondence principle where only the stor­age in the confi ning layers was taken into con­sideration. Sen (2000) has widened leaky aquifer hydraulic theory to non-Darcian flow and latter this analysis was extended based on volumet­ric approach by Birpinar and Sen (2004). For re­cent review on leaky aquifer hydraulic see Yeh & Chang (2013). During mathematical simulations of the drawdown the well radius of influence is very often represented as limiting factor in calcula­ tions. This parameter is difficult to determine in nature. It is also difficult to determine whether to use analytical model of finite or infinite radi­us of influence. Radius of influence is very often defi ned from empir ical formulas such as Sichardt equations (Powers et al., 2007) or it’s estimation is based on the expert judgement from the field study. From the theoretical and practical point of view it is interesting to observe differences in drawdown calculations between mathematical models which include finite or infinite radius of influence. In the paper mathematical analysis of draw-down in leaky aquifer during pumping test under steady-state conditions is presented. The analysis for the pumping tests with fully penetrating well in leaky aquifers with finite and infi nite radius of well influence is extended based on solutions of Jacob (1946) and Hantush (1960, 1964). The com­parisons are represented based on the various ra­tios between the drawdown for each of the differ­ent radius types under assumption that all other physical characteristic and pumping rate are the same. Ratios between different drawdowns are interpreted with various types of differences that can be interpreted as error analysis. Theoretical concepts are illustrated with numerical simula­tion. Finally, theoretical and numerical results are discussed. Mathematical model Conceptual model If the aquifer is not perfectly confined with upper and lower impermeable hydrogeological barrier leakage to the central water yielding unit – confined bed – may occur through the un­derlain or overlain semiconfining layer or aqui­tard. Leaky aquifers being either single or part of multi-layered aquifer systems and the degree of leakage between beds may become signifi­cant depending on the thickness and hydraulic conductivity of the confined bed which gives the main part of the aquifer yielding water. During pumping water from the aquitard water is also extracted through the confining layer. The con­ceptual model of the leaky aquifer is shown in the fig. 1. In parallel to this model several oth­er leaky aquifer conceptual models are available in the literature (Yeh & Chang, 2013) but are not taken in consideration. The leakage rates from the semiconfining lay­er – aquitard may be significant depending on hydraulic gradients around the pumping well. In the mathematical model of the pumping test from the leaky aquifer the thickness of the saturated part b‘ and vertical hydraulic conductivity of the aquitard K z p are taken into the account. It is hy­pothesised that leakage of water from the aqui­tard is strictly vertical and that no storage in this bed is present. The latter condition means that change of piezometric potential in the aquifer is simultaneous to change in the confined part of the aquifer. This part has transmissivity T that is defined as T=Kb; a product of hydraulic con­ductivity K and the thickness b of the confined part of the aquifer. Storage coefficient S of this defi nes vertical elastic properties of the aquifer. As a consequence of pumping from the aquifer the drawdown s appears on starting piezometric head h0 that is horizontal at any distance r from the well. The drawdown s at r at time t is defined as s(r,t)=h0-h(r,t). Radius of influence of ground­water pumping R is defined as the distance from the well where s(R,t)=0. Under steady-state pumping conditions at any time two models of ra­dius of influence of groundwater pumping R can be defi ned. I n the fi rst mathematical model of the leaky aquifer R is fi nite and constant; R=const. In the second mathematical model of the leaky aquifer R is infinite; R=8. Together with boundary and initial conditions already presented in the fig. 1 the following as­sumptions are applied in the mathematical model (Batu, 1998): the confined part of the aquifer is homogenous and isotropic, the extraction rate of the well Q is constant, the aquifer is horizontal, has constant thickness b and is overlain by an aquitard with constant vertical hydraulic con­ductivity K z p and constant thickness of the sat­urated part b’, the well penetrates entirely con­fined part of the aquifer, the diameter of the well is infinitesimally small with no storage and the groundwater flow in the confined part of the aq­uifer is horizontal. Governing equation Basic governing equation of the leaky aquifer in the vertical plane of the x, y, z Cartesian co­ ordinate system is defined as (for derivation see Miletic & Heinrich Miletic, 1981) Fig. 1. Schematic cross section of a leaky confined aquifer with finite and infinite radius of influence. ....".... ...."....- .... ............ + = (1) ........" ........" ...." ............ where .... =1.... ....3 6 (2) ....5 is defined as leakage factor. In the cylindrical system of the coordinates r and f the equation (1) can be rewritten as (Hantush, 1964) ....".... 1........ 1 ....".... - .... ............ + = (3) ........" ............ +...."........" ...." ............ and in the case of homogenous and isotropic aquifer according to . ....".... ........" + 1 .... ........ ........ - .... ...." = .... .... ........ ........ (4) Equation (4) can be recognized as modified Bessel equation of zero order (Lebedeev, 1970). For parameters and other symbols see fig. 1. Basic solution In the solution of governing equation (4) fol­lowing Hantush (1964) valid boundary and ini­tial conditions are defined as: ....(....,0)=0, .... =0 ....(....,....)=0, .... .8, .... =0 (5) F............ - .... lim= .... =0 D.E ........G 2........, In (5) last condition is consequence of Dar­cy law. Final solution of the governing equation (Hantush, 1964) is " P exp F-....- .... .... 4...."....G ....= ........ (6) 4........ Q K .... where u is defined as ....".... ....= (7) 4........ Integral (6) is known also as Hantush inte­gral. It is important in many fields of mathemat­ical physics and hydrology (Harris, 1997, 2001; Prodanoff et al., 2006). Detailed derivation of ba­sic solution of leaky aquifer partial differential equation is given elsewhere (Hantush 1964; Batu 1998; Lebbe, 1999). Steady state-solution in infinite leaky aquifer In real aquifers steady-state conditions are reached only after longer time t. If we suppose that t .8 than the limit of u is defined as V....".... lim....= lim=0 (8) U.P U.P 4........W and at sufficiently large time t u is small enough that u˜0. Consequently, integration bor­ders become from 0 to 8 and (6) becomes P exp F-....- ...." .... 4...."....G ....= ........ (9) 4........K .... E Based on Gradshteyn and Ryzhik (1994; equa­tion 3.471.9) P exp Z-....-.... ....\ K ........ =2....E]2^...._ (10) .... E From (9) and (10) also follows ...." ....= (11) 4...." and K0 is modified Bessel function of second kind of zero order. After short manipulation in (10) and (11) it can be shown that drawdown for the infinite leaky aquifer sI in steady-state con­ditions is .... ....` = (12)2............EZ........\ Which is the same results as de Glee (1930) defi ned initially through another derivation of equations. Steady state-solution in finite leaky aquifer General solution of modified Bessel equation of zero order (4) is (Lebedev, 1972) ....=....b....EZ........\+...."....EZ.... (13) ....\ where are C1,C2 – constants I0 – modified Bessel function of first kind of zero order. Boundary conditions are defined as (Jacob, 1946) ....(....,0)=0 ....=0 ....=0 ....(....)=0 (14) F............ - .... lim= D.E ........G 2........ Determination of C1 and C2 of (13) from (14) leads to the equation of drawdown sF in fi nite leaky aquifer. Constants are determined in the area where r = R. Elaboration of constants is not simple and straightforward, it is based on deriv­atives of s and limit properties of K0(x) and I0(x) functions. Derivation of C1 and C2 is first given in Jacob (1946) and thoroughly summarised and elaborated in Batu (1998) and Miletic and Hein­rich-Miletic (1981). Presentation of this deriva­tion is out of the paper’s scope. A fter definition of constants it follows: ....EZ.... .... ....\ ....e = 2........f....EZ........\-....EZ........\....EZ.... g (15) ....\ Comparison of the drawdown for finite and infinite radius of influence Definitions In hydrogeology we are frequently encoun­tering problem of choosing a proper aquifer con­ceptual model. Dealing with results of pumping test it is a question whether to use finite or in­fi nite model of well radius of influence. Available geological data are often not detailed enough or some information are missing for choosing the proper conceptual model. In such situation for calculations several models are used and their results are compared with the actual field mea­surements. In the engineering practice measurements and calculated values are often expressed together with certain errors, among them are relative dif­ference e r or absolute difference e a. The expres­sion of those help us to understand the reliability of predictions preformed based on measurements and differences among them in their application of the mathematical models. These concepts can be used also in the comparison between draw-down calculations in leaky aquifers with fi nite and in fi nite radius of well in fluence under steady state pumping conditions. We can define following differences and quo­tients. If x is any quatitative measure absolute difference e is defi ned as the absolute difference a between two measured values x1 and x2 ....i =|....b -...."| (16) If reference value xref is present absolute dif­ference e ’ is defined as a ....i3 =k....-....Dlmk (17) where x is any value from the model. The gen­eralized relative difference e is defined as r ....i |....b -...."| ....D = = (18) |....b +...."| |....b +...."| avg Alternatively, average relative difference e r can be defined as ino 2....i 2|....b -...."| ....D ....D = = = 2 (19) |....b +...."| |....b +...."| If the reference value xref is defi ned than rela­tive difference e ’ is r 3 k....-....Dlmk .... ....D= =p -1p (20) ....Dlm ....Dlm Sometimes e ’ is defined as r qr |vwyvx| ....D3 = = (21) stu|vw,vx| stu|vw,vx| Differences and ratios between sF and sI From mathematical point of view equations (12) and (15) are bearing some similarities. They can be easily used for the comparison between the modelled drawdown s in the aquifer with fi­nite radius of influence - sF with the aquifer with infi nite radius of influence - sI under steady state conditions and the same pumping rate Q. After short manipulation it can be shown from (12) and (15) that ....EZ........ ....e = -....EZ.... ....\ g (22) 2........f....` ....\....EZ.... ....\ From that point right hand part of the (22) in the brackets can be understood as factor which is correcting infinite aquifer drawdown sI to the finite aquifer drawdown sF. Based on this we can define correction factor cF ....EZ.... ....e =....EZ.... ....\ (23) ....\ ....EZ.... ....\ and consequently ....e = -....e] (24)2.... ........[....` cF is independent of Q and depends only on B and R which are geometrical and physical charac­teristics of the leaky aquifer. Due to aquifer physi­cal characteristics relation sI = cF is always present and due to the characteristics of modified Bessel functions K(x) and I(x) functional relation s= s 0 0 I F is always valid. Consequently, head in the leaky aquifer with the same hydraulic characteristics under the same pumping rate Q is higher in the aquifer with finite radius of influence than in the aquifer with infinite radius of influence. It can be illustrated that under some circumstance heads around the well in both cases can be nearly equal. We can further elaborate relations by dividing equation (15) with (12) and gaining ....EZ.... ....EZ.... ....e ....\ ....\ =1- (25) ....` ....EZ.... ....EZ.... ....\ ....\ or ....EZ.... ....EZ.... ....` -....e ....\ ....\ = (26) ....` ....EZ.... ....EZ.... ....\ ....\ From the properties of I0(x) and K0(x) in (25) and (26) follows sF =1, sI-sF =1, sI-sF=0 (27) sI sI From mathematical point of view equations (20) and (26) are similar. If we accept sI as a ref­erence value than (27) is relative error with sI as a reference value xref can be defined as ....EZ.... ....EZ.... ....\ ....\ ....D3(....`)= (28) ....EZ.... ....EZ.... ....\ ....\ Because sI = sF same conclusion as in (28) fol­lows from (21). Equation (28) is not just a mere mathemati­cal expression. It explains relation between two drawdown cur ves. If we have two leaky aquifers; with infinite and finite radius of influence under the same pumping rate and the same hydraulic characteristics e r’(sI) explains relative difference between both drawdown curves. Depending on r in the interval 0< e r’(sI)<1 ratio explains relative differences between both drawdown curves. If the e r’(sI) is close or equal to 1 the curves have the same spatial distribution, and if e r’(sI)= 0 d raw-down curve of sI is beyond the radius of in fluence R of the finite leaky aquifer. With the analogies of equations from (16) to (19) and according to the definition in (16) sub­tracting (15) from (12) following expression for e a can be derived ....EZ.... .... ....\....EZ.... ....\ .... ....i = = = 2........ ....EZ.... 2............e ....\ (29) ....EZ.... ....EZ.... ....\ ....\ ....` =....`....D3(....`) ....EZ.... ....EZ.... ....\ ....\ Absolute difference e a is expressed in length units. Comparing to e r’(sI) in (28) which is inde­pendent on pumping rate Q absolute difference e a depends on it. Relation between e a and e r’(sI) is also obvious. Generalized relative difference e r from (18) and with the help of (12) and (15) can be defined as ‚....EZ........\....EZ.... ....\ƒ ....D = (30) ‚2....EZ........\....EZ.... ....\-....EZ........\....EZ.... ....\ƒ Generalized relative difference e is also di- r mensionless quantity. It can be applied for anal­ysis when no preference to sI or sF are given. This is the case when we are not sure if model of fi­nite or in fi n ite radius of in fluence is valid and we want to keep both results. Consequently, average relative difference e avg followed from definitions r above is defined as ‚....EZ........\....EZ.... (31)ino ....D ....\ƒ ....D = = 2 ‚4....EZ.... ....\....EZ.... ....\-2....EZ........\....EZ.... ....\ƒ Results and discussion In the following chapter we are presenting numerical simulation results based on the pre­vious mathematical theory. Simulations were performed with build in numerical functions of modified Bessel functions of the fi rst kind I0 and the second kind K0 in Excel for Mac 16.16.1. and with the program for symbolic and numerical computation Mathematica for Mac version 11.3.0. Numerical results are discussed from the hydro-geological point of view. Estimation of leakage factor B Main physical parameter in simulations is leakage factor B defined in (2) which is combi­nation of two other physical parameters and one variable which in our simulation can be consid­ered as a constant. Those parameters are: trans- p missivity T of the confined unit and K z which is vertical permeability of semi-confining layer while b‘ defi nes head in the later. Based on the ex­pert judgement of T, K z p and b‘ we have estimated values of B. For simulations b‘ = 2 m was used. As expected in the real aquifers T was considered on the interval between 5·10-2 m2/s and 10-5 m2/s and K z p was considered in the interval from 10-9 m/s to 10-6 m/s. Calculated values of B are represent­ ed on double logaritmic scale in fig. 2. Fig. 2. Estimation of lea­ kage factor B at different transmissivity values T for confined layer and permea­bility of Kz p of semi-confi­ning layer at b’=2 m. In the range of applied T highest values of B p are present at K z = 10-9 m/s. In this case B val­ues are calculated in the interval between 173 m p and 12,247 m. Lowest B values are present at K z = 10-6 m/s. In this case B values are calculated in the interval between 5.5 m and 387 m. There­fore, total simulated range of B is from 5.5 m to 12,247 m. From the simulated values we can see that B is influenced by the K z p. In leaky aqufers semi-confining layer with vertical permeability p K z = 10-6 m/s due to the depression in confined layer it is highly unlikely that vertical flow will appear. Consequently, values of B in real aquifers tend to be in the higher part of the interval. Estimated values of B can be considered also in the evaluation of ratio R/B which is import­ant in presentation of simulation results on the relative scale r/R. Expected radius of influence R in real aquifers under the steady state condi­tions are in the range of 500 m to 20,000 m. Con­sequently, expected approximate range of R/B is in the interval from 0.005 to 20. Simulation of relative difference e r’(sI) To illustrate behaviour of e r’(sI) given by equa­tion (28) we have chosen aquifer with influence radius R of 5,000 m. Such radius of influence can be expected in many natural aquifers. Results of calculations are presented in the fig. 3 for leak­age factors B from 50 m to 20,000 m. At relatively small values of B large part of the curve is flat­ter reflecting e r’(sI)=0. At higher r curve sharply turns up to values near e r’(sI)=1. With higher val­ues of B curvature is becoming flatter and values of e r’(sI) are becoming to rise slowly. Curves below B=5,000 m which is the same value as chosen R are concave with higher B they become convex. For high B values and at lower r values e r’(sI) starts to rise quickly and then at middle values of r the curve flattens and become nearly linear. By simple reasoning it can be shown from (28) that results for different radius of in fluence R can be presented on the relative scale r/R. Diagram presented in fig. 4 is valid for any R at the same ratio R/B between radius of influence and leakage factor. Shape of lines are the same as they are on the fig. 3 and therefore reflecting the same rela­tions as they are in the diagram for exact radius of influence. The diagram in fig. 4 can be under­stood as scaled diagram. Similarly, as before at relatively small values of B large part of the curve is equal to e r’(sI)=0 and then at the right side of the diagram the curve sharply turns up to values near e r’(sI)=1. From the diagram we can observe that for values of R/B < 1 the curves are concave and for values R/B > 1 the curves turn to be convex. Curves on both figures (figs. 3 and 4) are rep­resenting comparison of the drawdown sF in the aquifer with fi nite influence of well and the draw-down sI in the aquifer with infinite radius of in­fluence. Values around 0 are showing that practi­cally no difference is present among drawdowns when values of B or R/B are relatively small. Consequently, if we are dealing with relatively extensive leaky aquifer it is not important if we calculate drawdowns for finite or infinite radius model. In such cases the difference among draw-downs become important only near the radius of influence R. Estimation whether we can describe aquifer with finite or in fi nite aquifer radius of in­ Fig. 3. Relative difference e r ’ with reference value sI plotted on the regular dis­tance scale. fluence becomes important with larger B values. Therefore, when semiconfining layer has several orders of magnitude lower vertical permeability than in con fi ned layer it become impor tant which analytical model for radius of influence is used. Differences become bigger close to the well com­paring to higher B values where differences are important far away from the pumping well. Simulation of generalized relative difference Generalized relative differences are present­ed only for relative distance r/R and are given in the fig. 5. Shape of the lines for different ratios R/B are nearly similar to the lines in fig. 4 where relative difference is shown. They are more con­vex comparing to relative difference e r’(sI). Fig. 4. Relative difference e r ’ with reference value sI plotted on the relative dis­tance scale Comparison between relative differences Lines in fig. 4 and fig. 5 have similar shape therefore one may ask question whether there is any difference between the lines. For the compar­ison we have calculated both differences for two different ratios R/B = 1 and R/B = 0.25 respectively. Results are shown on the fig. 6. In spite of the sim­ilar shapes of the curves differences among curves exist. From the equations (28) and (30) it can be shown that for the same physical parameters R and B relative difference e r’(sI) is always larger than e r . In the theoretical part of the paper we are not rep­resenting derivatives of (28, 30) but it can be illus­trated that e r’(sI) always approach value of 1 (right part of the curve) slowly than e r . Behaviour of e r is the consequence of its definition in (18) where com­paring to (20) value is weighted by sI. Fig. 5. Relative difference e r’ plotted on the relative scale r/ R. Fig. 6. Comparison of simulation between e r’(sI) and e r with the same ratio R/B plotted on the relative scale r/R. Conclusions In spite of the fact that in hydrogeological quantification of aquifers and their groundwater flow numerical models are widely applied, devel­opment of analytical mathematical models is still important. Analytical approach to groundwater flow enables different and deeper insight into the relations between different geometrical elements in the aquifers and their conceptual models. An­alytical models are important for the control of numerical results and are very often applied as a scoping calculation representing first step in the consideration of hydraulic conditions in the aquifer. In the paper we have presented classical der­ivation of the head distribution in the leaky aq­uifer under steady state pumping conditions. We have shown that infinite limit of Hantush inte­gral which represents solution of the non-steady state pumping conditions in the leaky aquifer is solution for the steady state conditions. We have shown that solutions for steady state con­ ditions under finite and infi nite pumping well radius of influence are mathematically similar and that based on this characteristics compari­son between them can be performed. They can be represented as relative and absolute differences of drawdowns for each model. In the case when available data do not allow us to make a decision on the type of the radius of influence of the pump­ing well, they can help us in the interpretation of various errors due to application of different an­ alytical models of pumping test. We have shown that at larger leakage factors B determination of radius of influence R for the large part of the aq­uifer is not important, they become important at larger factors B when contrast between permea­ bilities in the semi-confining unit and confined unit becomes larger. Under such condition differ­ences in drawdown are important in the vicinity of the pumping well. For further consideration similar relation for non-steady solutions of the leaky aquifer are also interesting. Acknowledgment Suggestions and coments from Jože Ratej and Žiga Brencic greatly improved the quality of the paper. The author acknowledges the financial support from the Slovenian Research Agency (research core funding No. P1-0020 “Groundwater and geochemistry”. References Batu, V. 1998: Aquifer hydraulics – a compre­hensive guide to hydrogeologic data analysis. John Wiley & Sons. Inc.: 727 p. Birpinar, M.E. & Sen, Z. 2004: Forcheimer groundwater flow law type curves for leaky aquifers. Journal of Hydrologic Engineering, 9/1: 51-59. https://doi.org/10.1061/(ASCE) 1084-0699(2004)9:1(51) De Glee, G.J. 1930: Over Grondwaterstroomingen bij Wateronttrekking door van Putten, J. Waltman: 175 p. DeWiest, R.J.M. 1965: Geohydrology. John Wiley & Sons. Inc.: 532 p. Gradshteyn, I.S. & Ryzhik, I.M. 1994: Table of in­tegrals, series, and products. Academic Press: 1204 p. Hantush, M.S. 1959: Nonsteady flow to flowing wells in leaky aquifers. Journal of Geophysical Research, 64: 1043-1052. Hantush, M.S. 1960: Modification of the theo­ry of leaky aquifers. Journal of Geophysical Research, 65: 3713-3725. Hantush, M.S. 1964: Hydraulics of wells. In: Chow, V.T. (ed.): Advances in Hydrosciences. Academic Press, 1: 282 – 432. Hantush, M.S. & Jacob, C.E. 1955: Non-steady radial flow in an infinite leaky aquifer. Transactions, American Geophysical Union, 36: 95 - 100. Harris, F.E. 1997: New approach to calculation of the leaky aquifer function. International Journal of Quantum Chemistry, 63: 913-916. Harris, F.E. 2001: On Kryachko’s formula for the leaky aquifer function. International Journal of Quantum Chemistry, 81: 332-334. Herrea, I. 1970: Theory of multiple leaky aqui­ fers. Water Resources Research, 6: 185-193. https://doi.org/10.1029/ W R006i001p00185 Herrea, I. & Figueroa, G.E. 1969: A correspon­dence principle for the theory of leaky aqu­ifers. Water Resources Research, 5: 900-904. Jacob, C.E. 1946: Radial flow in a leaky artesian aquifer. Transactions, American Geophysical Union, 27: 198 - 205. Lebbe, L.C. 1999: Hydraulic parameter identifi­cation. Springer: 359 p. 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CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.015 Primerjava rezultatov modeliranja vsebnosti nitrata v vodi pod koreninskim obmocjem tal v lokalnem in regionalnem merilu Comparison of the modeling results of nitrate concentrations in soil water below the root zone in the local and regional scale Jože UHAN & Mišo ANDJELOV Agencija Republike Slovenije za okolje, Vojkova 1b, SI-1000 Ljubljana, Slovenija; e-mail: joze.uhan@gov.si Prejeto / Received 15. 6. 2018; Sprejeto / Accepted 11. 11. 2018; Objavljeno na spletu / Published online 20. 12. 2018 Kljucne besede: podzemna voda, nitrat, tla, aluvialni vodonosnik, Spodnje Savinjska dolina Key words: groundwater, nitrate, soil, alluvial aquifer, Spodnje Savinjska dolina Izvlecek Na raziskovalnem obmocju plitvega aluvialnega vodonosnika Spodnje Savinjske doline v osrednjem delu Slovenije, predstavljamo primerjalno analizo rezultatov modeliranja vsebnosti nitrata v vodi pod koreninskim obmocjem tal, v lokalnem in regionalnem merilu z enodimenzijskim modelom DNDC (ang. Denitrification – Decomposition) in z regionalnim modelom GROWA–DENUZ (nem. Großräumiges wasserhaushalt – Denitrifikation im durchwurzelten Boden). Ob uporabi koncepta hidroloških enot HRU (ang. Hydrological Response Unit) in Cohenove Kappa statisticne analize ujemanja ter ocenjevanja zanesljivosti rezultatov prostorskega modeliranja nitrata v vodi pod koreninskim obmocjem tal smo ugotovili in interpretirali predele najvecjega ujemanja in razhajanja modelskih rezultatov. Dobro ujemanje je bilo ugotovljeno pri najvišjih modeliranih vrednostih, odstopanja pa so bila zaznana predvsem v nižjem delu razpona modeliranih vrednosti nitrata v vodi. Vzroke odstopanja lahko domnevno išcemo predvsem v razlikah pri ocenah denitrifikacijskih pogojev v anaerobnih pogojih hipoglejev in psevdoglejev s podzemno vodo plitvo pod tlemi in v razlikah pri scenarijih gnojenja ter kmetijske prakse. Abstract The article presents a comparative analysis of the modeling results of nitrate concentrations in water below the root zone of the soil in the local and regional scale. In this research, the field-scale DNDC (Denitrification – Decomposition) and the regional-scale GROWA–DENUZ (ger. Großräumiges wasserhaushalt – Denitrifikation im durchwurzelten Boden) models were applied to the study area of the shallow aluvial aquifer of the Spodnje Savinjska dolina in the central part of Slovenia. Using the concept of Hydrological Response Unit (HRU) and Cohen Kappa statistical analysis of the degree of agreement and assessment of the reliability of the results of spatial modeling of nitrate in soil water below the root zone, we determined and interpreted the areas of maximum agreement and disagreement of model results. A good agreement was found at the highest modeled concentrations of nitrate in soil water, whereas the greatest deviations were detected primarily in the lower part of the range. The main reasons for disagreement were differences in the estimation of the denitrification conditions in the anaerobic environments of gley-soils with the shallow groundwater and differences in fertilisation scenarios and agricultural practices. Uvod Vsebnost nitrata v podzemni vodi predsta­ vlja resno grožnjo okolju na regionalni in lokalni ravni (Kurkowiak, 2017). Tudi ocene kemijskega stanja podzemnih voda, kot jo zahteva okvirna direktiva o vodah (Direktiva 2000/60/ES), v na­crtih upravljanja voda Slovenije že desetletje iz­postavljajo vec vodnih teles, kjer vsebnost nitrata v podzemni vodi presega mejno vrednost (MOP, 2011, 2016). Vzroke najpogosteje povezujemo s po­manjkljivo komunalno urejenostjo in intenzivnim kmetovanjem ob uporabi manj primernih kme­ tijskih praks. Obe podrocji se urejata v okvirih, ki jih predpisujeta evropski direktivi o cišcenju komunalne odpadne vode (Direktiva 91/271/EGS) in direktiva o varstvu voda pred onesnaževanjem z nitrati iz kmetijskih virov (Direktiva 91/676/ EGS). Porocevalske sheme terjajo tudi strokovno argumentirane ocene ucinkov nacrtovanih ukre­pov in napoved casovnic izboljšanja kemijskega stanja voda s skrajnim casovnim mejnikom 2027, ko naj bi dosegli zastavljene cilje dobrega stanja voda (Matoz et al., 2016). Agencija Republike Slo­venije za okolje je v sodelovanju z nemškim razi­ skovalnim središcem JÜLICH za obmocje celotne Slovenije prilagodila modelski sistem GROWA­-DENUZ/WEKU (Kunkel & Wendland, 2006; Wendland et al., 2008), ki poleg bilance vode upo­števa bilanco dušika ter modelira tok dušika pre­ko tal in vodonosnika v površinska vodna telesa. Za prvo oceno zanesljivosti rezultatov tega kom­pleksnega modelskega sistem smo na obmocju pli­tvega aluvialnega vodonosnika Spodnje Savinj­ske doline s podzemno vodo v slabem kemijskem stanju izdelali primerjalno analizo rezultatov re­gionalnega modeliranja toka dušika preko kore­ ninskega obmocja tal GROWA-DENUZ (Kunkel & Wendland, 2006; Andjelov et al., 2014, 2015) in rezultatov lokalnega modela toka dušika iz ko­ reninskega obmocja tal DNDC (Li et al., 1992) v posameznih talnih profilih. Zanimala nas je sto­pnja ujemanja modelskih rezultatov v lokalnem in regionalnem merilu v izbranem letu 2008, ko so bile opravljene tudi obsežne terenske meritve, la­boratorijske analize in študijske raziskave (Uhan, 2011), ter primernost uporabe modelskega sistema GROWA-DENUZ/WEKU za potrebe simuliranja ucinkov ukrepov v smeri izboljšanja kemijskega stanja podzemnih voda. Raziskovalno obmocje Raziskovalno obmocje obsega 73,5 km2 velik aluvialni vodonosnik Spodnje Savinjske doline (sl. 1) s tremi izrazitimi nivoji aluvialnih teras v holocenskih in pleistocenskih pešceno-prodnih recnih naplavinah (sl. 2). Zanj so znacilne obsežne kmetijske obdelovalne površine: travniki (24 %), njive in vrtovi (33 %) ter hmeljišca (15 %), urba­niziranih površin je okoli 19 % (MKGP, 2007) (sl. 3). V primerjalno analizo rezultatov modeliranja vsebnosti nitrata pod koreninskim obmocjem tal so vkljucene le kmetijske površine. Plitva tla so pretežno rjava evtricna (41 %) in obrecna (25 %), predvsem v obrobnih delih pa so prisotni hipog­leji in psevdogleji (21 %) (MKGP, 2007) (sl. 4). Debelina tal reprezentativnih profi lov omenje­nih talnih enot v Trnavi, Orli vasi in Arji vasi je v razponu od 50 do 64 cm (Zupan et al., 2008), globina koreninjenja pa v posameznih primerih presega omenjeno debelino tal (Andjelov et al., 2016a). Globina do podzemne vode je po podatkih državnega monitoringa Agencije Republike Slo­venije za okolje v razponu od 0,7 do 7,5 m, s pov­precjem 2,4 m in standardnim odklonom gladine podzemne vode 2,0 m (sl. 2). Aluvialni vodono­snik z medzrnsko poroznostjo pleistocenskih in holocenskih pešcenih in prodnatih sedimentov s povprecno 21.450.000 m3 obdobno razpoložljivih kolicin podzemne vode (Uhan, 2015), zagotavlja pomembne vodne vire regionalne oskrbe, s sicer zahtevnim varovanjem in zagotavljanjem stan­dardov pitne vode. Sl. 1. Študijsko obmocje Spodnje Savinjske doline. Fig. 1. Study area of Spodnje Savinjska dolina. Sl. 2. Hidrogeološka karta Spodnje Savinjske doline (Viri podatkov: Uhan, 2011; Souvent et al., 2014). Fig. 2. Hydrogeological map of Spodnje Savinjska dolina (Data sources: Uhan, 2011; Souvent et al., 2014). Sl. 3. Raba prostora (Vir podatkov: MKGP, 2007). Fig. 3. Land use (Data sou­rce: MKGP, 2007). Sl. 4. Vrsta tal (Vir podat­ kov: MKGP, 2007; Vidic et al., 2015). Fig. 4. Soil types (Data so­ urce: MKGP, 2007; Vidic et al., 2015). Podatki Podatki za regionalno modeliranje toka nitrata preko koreninskega obmocja tal, so crpani iz ura­dnih nacionalnih podatkovnih zbir ministrstev, agencij, uprav, zavodov, inštitutov in fakultet ter nekaterih mednarodnih inštitucij (Tabela 1). Me­rila in locljivosti prostorskih podatkovnih slojev so razlicna: merila kart so v razponu od 1: 25.000 do 1: 250.000, locljivosti prostorskih rastrov pa so od 100 × 100 metrov do 50 × 50 kilometrov. Osnov­ne vhodne podatke za model GROWA-DENUZ so predstavljali podatki o neto bilanci dušika v kme­tijstvu (Sušin et al., 2015) na ravni graficne enote rabe kmetijskega gospodarstva GERK, ki jih zbi­rajo na Agenciji Republike Slovenije za kmetijske trge in razvoj podeželja. Podatki o staležu goveda so vzeti iz zbirke GOVEDO, ki jo vodijo na Kme­tijskem inštitutu Slovenije. Atmosferski nanos pa je bil na kmetijskih obmocjih Slovenije za potrebe regionalnega modeliranja ocenjen na podlagi po­datkovne zbirke EMAP (EEA, 2002). Lokalno modeliranje toka nitratov preko re­ prezentativnih profilov tal pa je podatkovno temeljilo predvsem na podatkih iz zbirke pedo­ loških profilov Centra za pedologijo in varstvo okolja Biotehniške fakultete (Zupan et al., 2008), na podatkih iz smernic za strokovno utemeljeno gnojenje (Mihelic et al., 2010), na razpoložljivih modelskih podatkovnih knjižnicah o fiziologiji izbranih rastlin (Li, 2009) in na zbirkah meteo­roloških podatkov Agencije Republike Slovenije za okolje. Primerjalna analiza vkljucuje obdobje hi­drološkega leta 2008, ko so bile na obmocju vo­donosnika Spodnje Savinjske doline opravljene tudi obsežne študijske raziskave (Uhan, 2011). Hidrološko leto 2008 se po kolicinskem obnavlja­nju podzemne vode uvršca med zmerno vodna­te s +18 % odstopanjem od obdobnega povprecja 1981-2010 (U han, 2015). Tabela 1. Podatkovne zbirke za modeliranje toka nitratov v Spodnje Savinjski dolini z modeloma GROWA-DENUZ in DNDC. Table 1. Databases for nitrogen flux modelling in Spodnje Savinjska dolina with GROWA-DENUZ and DNDC model. Model GROWA-DENUZ Vrsta podatkov / Type of data Podatkovna zbirka / Database Merilo za vektorski podatek ali pro­storska locljivost za rasterski poda­tek / Scale for vec­tor data or spatial resolution for ras­ter data Vir podatkov / Data source K limatski podatki (1971-2000) / Climate data (1971-2000) Padavine (maj - oktober), padavine (november - april), potencialna evapotranspi­racija / Precipitation (May - October), precipitation (November - April), potential evapotranspiration 100 × 100 m Agencija Republike Slovenije za okolje, Urad za mete­orologijo in hidrologijo / Slovenian Environment Agency, Meteorology and Hydrology Office Pokrovnost tal / Land cover Vrsta rabe tal / Land use categor y 1: 100.000 Zbirka podatkov CORINE / CORINE data base Podatki o tleh / Soil data Tipi tal, tekstura tal, efektiv­na poljska kapaciteta, globina koreninjenja / Soil types, soil texture, effective field capaci­ty, rooting depth 1: 25.000 Ministrstvo za kmetijstvo, goz­darstvo in prehrano; Univerza v Ljubljani, Biotehniška fakulteta, Oddelek za agronomijo; Kmetijski inštitut Slovenije / Ministry of Agriculture, Forestry and Food; University of Ljubljana, Biotechnical Faculty, Centre for Soil and Environment Science; Agricultural Institute of Slovenia Podatk i o površju / Relief data Digitalni model višin / Digital elevation model 100 × 100 m Geodetska uprava Republike Slovenije / Surveying and Mapping Authority of the Republic of Slovenia Geološki podatki / Geological data Geološka karta Slovenije / Geological map of Slovenia 1: 100.000 Geološki zavod Slovenije / Geological Survey of Slovenia Hidrološki podat­ki / Hydrological data Prispevna obmocja, dnev­ni pretoki (1971 - 2000) / Catchment areas, daily runoff (1971 - 2000) 1: 25.000 Agencija Republike Slovenije za okolje, Urad za mete­orologijo in hidrologijo / Slovenian Environment Agency, Meteorology and Hydrology Office Hidrografski podatki / Hydrographical data Recna mreža, umetno izsušena obmocja / River network, arti­ficially drained areas 1: 25.000 Geodetska uprava Republike Slovenije, Ministrstvo za kme­tijstvo, gozdarstvo in prehrano / The Surveying and Mapping Authority of the Republic of Slovenia, Ministry of Agriculture, Forestry and Food Hidrogeološki podatki / Hydrogeological data Hidrogeološka karta Slovenije, tipologija podzemne vode, hi­droizohipse, globina do podze­mne vode, hidravlicna prepu­stnost / Hydrogeological map of Slovenia, groundwater typo­logy, water table contours, groundwater depth, hydraulic permeability 1: 250.000 1: 100.000 1: 25.000 Geološki zavod Slovenije; Agencija Republike Slovenije za okolje, Urad za meteorologijo in hidrologijo / Geological Survey of Slovenia, Slovenian Environment Agency, Meteorology and Hydrology Office Podatki o kako­vosti voda / Water quality data Kakovost podzemnih in po­vršinskih voda (1995 - 2011) / Groundwater and surface wa­ter quality data (1995 - 2011) 1: 25.000 Agencija Republike Slovenije za okolje, Urad za mete­orologijo in hidrologijo / Slovenian Environment Agency, Meteorology and Hydrology Office Tockovni viri du­šika / Point sour­ces of nitrogen Cistilne naprave komunalnih in industrijskih odpadnih voda, greznice / Municipal waste water treatment plants, industrial treatment plants, cesspools 1: 25.000 Agencija Republike Slovenije za okolje, Urad za meteorolo­gijo in hidrologijo; Ministrstvo za okolje in prostor / Slovenian Environment Agency, Meteorology and Hydrology Office; Ministry of environment and spatial planing Razpršeni viri dušika / Diffuse sources of nitrogen Atmosferski nanos dušika, presežek dušika v kmetijstvu / Atmospheric N deposition, agricultural N surpluses 50 × 50 km, 100 × 100 m European Monitoring and Evaluation Programme (EMEP), K metijski inštitut Slovenije / European Monitoring and Evaluation Programme (EMEP), Agricultural Institute of Slovenia Model DNDC Vrsta podatkov / Type of data Podatkovna zbirka / Data base Vir podatkov / Data source Podatki o podne­bju (leto 2008) / Climate data (year 2008) Dnevna višina padavin, dnev­no povprecje temperature zra­ka / Daily precipitation, daily average air temperature Agencija Republike Slovenije za okolje, Urad za me­teorologijo in hidrologijo / Slovenian Environment Agency, Meteorology and Hydrology Office Podatki o tleh / Soil data Talni informacijski sistem Slovenije / Soil information system of Slovenia Univerza v Ljubljani, Biotehnicna fakulteta, Center za pedologijo in varstvo okolja / University of Ljubljana, Biotechnical Faculty, Centre for Soil and Environment Science Podatki o rastli­nah / Crop data Podatki o fiziologiji in fenolo­giji rastlin / Crop phenology and physiology data Knjižnica rastlin DNDC (Li, 2009) / Crop library of DNDC (Li, 2009) Podatki o kme­tijski praksi / Agricultural ma­nagement data Podatki iz slovenskih smer­nic za strokovno utemeljeno gnojenje / Data from Slovene guidelines for expert based fertilization Ministrstvo za kmetijstvo, gozdarstvo in prehra­no (Mihelic in sod., 2010) / Ministry of Agriculture, Forestry and Food (Mihelic et al., 2010) Metode Modeliranje toka nitrata v regionalnem merilu Tok nitrata preko koreninskega obmocja tal je bil v regionalnem merilu v prostorski locljivosti 100 × 100 metrov modeliran v okolju GROWA­-DENUZ (Kunkel & Wendland, 2006; Kunkel et al., 2010), ki je temeljil na prostorskih podatkov­nih slojih regionalne vodne bilance (Andjelov et al., 2016a) in neto bilance dušika v kmetijstvu (Sušin et al., 2015). Ob upoštevanju Michaelis­-Mentenove kinetike (Michaelis & Menten, 1913) so bili ocenjeni denitrifikacijski pogoji kombi­nirani z izracunanimi presežki dušika (Sušin et al., 2015) in zadrževalnimi casi pronicanja vode v obmocju korenin ter predstavljeni kot funkcija povprecne poljske kapacitete in hitrosti odtoka s pronicanjem (sl. 5). Kot referencne vrednosti so bile uporabljene ocenjene hitrosti denitrifikaci­je za srednjeevropske tla (Wienhaus et al., 2008). Ocene hitrosti denitrifikacije, ki so letno v raz­ponu od okoli 10 do preko 100 kg N na hektar, temeljijo na vrsti tal in geološki podlagi ter vpli­vu plitve podzemne vode. Zadrževalni casi izce­dne vode so v koreninskem obmocju tal ocenjeni preko efektivne poljske kapacitete (Müller & Ra­issi, 2002; Hennings, 2000). Ocena relativne de­nitrafikacijske izgube v tleh temelji na razmerju med iznosom dušika iz tal po denitrifikaciji, ki jo prinaša rešitev Michaelis-Mentenove enacbe, in vnosom dušika iz razpršenih virov. Vsebnosti nitrata v izcedni vodi so v modelu GROWA-DE­NUZ ocenjene ob upoštevanju hitrosti pronicanja vode preko koreninskega obmocja tal za celotno obmocje Slovenije (Andjelov et al., 2016a, 2016b). Za vrednotenje rezultatov modela GROWA-DE­NUZ smo primerjali modelske rezultate z rezul­tati terenskih meritev nitrata v podzemni vodi (Uhan, 2011) in neparametricni Spermanov ko­eficient nakazuje korelacijo ranga 0,87 (a=0,05). Modeliranje toka nitrata v lokalnem merilu Za simuliranje biogeokemijskih procesov du­šikovega kroga v lokalnih pogojih kmetijskih ekosistemov na plitvem vodonosniku Spodnje Savinjske doline smo na posameznih reprezenta­tivnih profilih tal v Trnavi, Orli vasi in Arji vasi (Zupan et al., 2008) (sl. 1) uporabili enodimenzij­ski model DNDC (Li et al., 1992). Model omogo­ca povezavo med vhodnimi parametri okolja in izhodi iz dušikovega kroga tal v obliki biomase, plinov in izpiranja. Modelske procese poganjajo primarne gonilne sile v okolju, kot so procesi v ozracju, tleh in vegetaciji, ob upoštevanju kme­tijske prakse oz. clovekove aktivnosti (sl. 5). Mo­del DNDC sestavljata dve osnovni komponenti, ki rešujeta enacbe klime tal z izracunom iztoka vode in enacbe biogeokemijskih procesov duši­ka v tleh. Prvo modelsko komponento sestavljajo trije podmodeli: klima tal, rast vegetacije in de­ kompozicija. V okviru te komponente je možna napoved faktorjev tal: temperature in vlage tal, pH in oksidacijsko-redukcijskega potenciala ter vsebnosti substratov na podlagi vedenja o tleh, rastlinstvu in podnebju, ki lahko pomembno vpli­va na rezultate biogeokemijskih procesov (Uhan, 2018). Druga komponenta je sestavljena iz nitri­fikacijskega, denitrifikacijskega in fermentacij­skega podmodela, ki omogocajo napoved emisije plinov iz sistema tla - rastline. Model predstavlja povezavo med ogljikovim in dušikovim biogeoke­mijskim ciklom in primarnimi gonilnimi silami ter med drugim simulira tudi kolicino letnega izhoda dušika iz koreninskega obmocja tal, ki ogroža kakovost podzemne vode tudi v zasicenem delu vodonosnika. Pri tem je pomemben proces denitrifikacije, ki se povezuje z nasicenostjo tal in pojavom anaerobnosti. Model DNDC preko Nern­ stove enacbe (Nernst, 1889) oceni oksidacijsko­ redukcijske pogoje tal (Eh), nato pa ob upošte­vanju Michaelis-Mentenove kinetike (Michaelis & Menten, 1913) simulira aktivnosti anaerobnih mehanizmov in izracuna stopnjo denitrifikacij­ske redukcije nitrata (Stumm & Morgan, 1981; University of New Hampshire, 2017). Analiza obcutljivosti modela DNDC je z metodo Monte Carlo (Metropolis & Ulam, 1949) v primeru repre­zentativnega pedološkega profila v Latkovi vasi izpostavila pomemben vpliv na izpiranje dušika predvsem s strani dveh vhodnih parametrov: hi­ dravlicne prevodnosti tal in kolicine uporabljenih gnojil (Uhan, 2011). Umerjanje modela oz. vred­notenje rezultatov modela DNDC je bilo izvedeno preko primerjave z merjenimi podatki poljskega poskusa v Latkovi vasi leta 2000 (Pintar et al., 2005) in neparametricni Spermanov koeficient korelacije ranga je dosegel vrednost 0,76 (a=0,05). Statisticna primerjalna analiza modelskih rezultatov Primerjava rezultatov modeliranja vsebnosti nitrata v vodi pod koreninskim obmocjem tal v regionalnem in v lokalnem merilu je zahtevala posplošitev oz. prenos modelskih izhodnih po­datkov na primerljive prostorske enote. Primer­ljive enote prostora, znotraj katerih naj bi bile vhodne velicine hidrološkega modela predpos­tavljeno homogene, so z enako vrsto tal, rabo prostora in naklonom površja defi nirane kot hi­drološke enote HRU (angl. Hydrological Respon­ Izracun povprecja izpiranja dušika iz modelskih rasterskih celic 100 x 100 metrov za posamezno hidrološko enoto HRU / Calculation of average nitrogen leaching valued from model raster cells 100 x 100 meters to individual hydrological response unit HRU Dodelitev modeliranih vrednosti izpiranja dušika iz talnega profila posamezni hidrološki enoti HRU / Assign of modeled nitrogen leaching values from soil profile to individual hydrological response unit HRU Sl. 5. Shema modelskih postopkov in primerjava modelskih rezultatov (po: Kunkel & Wendland, 2006; Salas, 2010). Fig. 5. The scheme of model procedures and comparison of the model results (after: Kunkel & Wendland, 2006; Salas, 2010). Sl. 6. Hidrološke enote (HRU) za dolocene tipe tal in rabe prostora v Spodnje Savinjski dolini. Fig. 6. Hydrological re­sponse units (HRU) for a given soil types and land uses in Spodnje Savinjska dolina. se Unit) (Arnold et al., 1998) (sl. 6). Prostorskim enotam z enako vrsto tal, rabo prostora in nak­lonom površja lahko pripišemo enake hidrološke znacilnosti prostora. Hidrološkim enotam HRU študijskemu obmocju Spodnje Savinjske doli­ne so bila v primeru modeliranja v regionalnem merilu izracunana prostorska povprecja letnega izpiranja dušika iz modelskih rastrskih celic 100 × 100 metrov, v primeru modeliranja v lokalnem merilu pa so bile hidrološkim enotam HRU pri­pisane vrednosti modeliranja letnega izpiranja dušika iz reprezentativnih profilov tal (sl. 3) s prevladujocimi rabami prostora (sl. 4). Statistic­na primerjalna analiza modelskih rezultatov je v tako pripravljenem rastrskem zapisu temeljila na matriki pravilnosti razvršcanja oz. matriki zamenjav, iz katere je izracunana mera ujemanja ali skladnosti (sl. 5). Cohenov koeficient . (kapa) pokaže stopnjo ujemanja klasifikacij dveh mo­delskih rezultatov oz. za koliko je ujemanje med modelskima rezultatoma boljše od nakljucnega ujemanja. Z izracunom koeficienta . smo oprede­lili delež ujemanja modelskih rezultatov, ki pre­sega pricakovano nakljucje (Cohen, 1960): ................-................ .= , 1-................ kjer je P o delež opazovanega ujemanja, P c pa je delež nakljucnega ujemanja. Podobno kot korelacijski koeficient je tudi Cohenov koeficient . v razponu od -1 do +1, kjer negativne vrednosti govorijo o ujemanju, ki je slabše od nakljucja, vrednost +1 pa nakazuje odlicno ujemanje. Primerjalna analiza rezulta­tov modeliranja vsebnosti nitrata v vodi pod ko­reninskim obmocjem tal v regionalnem in v lo­kalnem merilu Spodnje Savinjske doline je bila v GIS okolju izvedena s sistematicnim in robu­stnim postopkom Kappa Stats (Jenness & Wynne, 2007). Rezultati in razprava Vsebnosti nitrata v vodi pod koreninskim ob­ mocjem tal smo v enodimenzijskem modelskem okolju DNDC najprej modelirali v posameznih reprezentativnih profi lih tal ob izbranih scena­rijih rabe prostora in kmetijske prakse (Uhan, 2011). Ob tem smo za potrebe regionalizacije modelskih rezultatov letnega izpiranja dušik iz talnega profi la privzeli poenostavljen koncept hidrološke enote HRU. Hidrološke enote HRU so osnovne enote izracunov v modelskem okolju SWAT, ki izvor no temeljijo na vrstah tal, rabah prostora in naklonih površja, znotraj katerih naj bi bile vse vhodne velicine modela predpostav­ljeno homogene (Arnold et al., 1998). S tremi re­prezentativnimi vrstami tal Spodnje Savinjske doline (obrecna tla, evtricna rjava tla, hipoglej) in tremi vrstami kmetijske rabe prostora (hme­ljišce, njiva in vrt, trajni travnik) smo vzposta­vili prostorsko shemo devetih prevladujocih hi­droloških enot HRU (sl. 6), s katerimi smo uspeli pok r iti 89 % celotnega raziskovalnega prosto­ra. Rezultati modelskih simulacij DNDC so za izbrano analizirano leto 2008 v razponu od 1,7 do 36,9 kg N/ha. Pri pregledu površin obdeloval­ nih kmetijskih zemljišc posameznih hidroloških enot in modelskih izracunov izpiranja dušika iz reprezentativnih pedoloških profi lov mocno izstopajo hmeljišca (sl. 7 in 9) z obravnavano površino 1.212 ha in izpiranjem dušika v raz­ponu od 13,6 kg N/ha na hipogleju Arje vasi do 36,9 kg N/ ha na obrecnih tleh Orle vasi. Koncept hidroloških enot HRU smo zara­di potreb primerjalne analize uporabili tudi za posplošitev rezultatov modela GROWA-DENUZ z izvorno prostorsko locljivostjo 100 × 100 me­trov (Andjelov et al., 2014, 2015). Rezultati regi­onalnega modela GROWA-DEN UZ so za izbrano analizirano leto 2008 po posameznih hidroloških enotah HRU v razponu od 8,7 do 37,0 kg N/ ha. Tudi v tej modelski simulaciji izstopajo hidro­loške enote s hmeljišci in sicer v razponu od 23,8 do 37,0 kg N/ ha. Model GROWA-DENUZ simu­lira tok dušika v manjšem razponu, vendar pa je standardni odklon rezultatov obeh modelih zelo podoben: 10,2 kg N/ha pri modelu DNDC in 9,6 kg N/ ha pri modelu GROWA-DENUZ (Tabe­la 2). Statisticna primerjalna analiza podatkovnih slojev je terjala prostorsko klasifikacijo rezulta­tov obeh modelskih simulacij, ki je bila izvedena glede na število izhodišcnih karakteristik hidro­loških enot HRU (trirazredna klasifikacijska she-ma) in glede na verjetnostno porazdelitev mode­liranih vrednosti (dvorazredna klasifikacijska shema). Podlaga dvorazredni klasifikacijski shemi (sl. 7 in 8) je vrednost prevoja logaritemske verje­tnostne porazdelitve (Panno et al., 2006), podlaga trirazredni klasifikacijski shemi (sl. 9 in 10) pa je Fisher-Jenksov algoritem naravnih mejnih vred­nosti (Slocum et al., 2005). Mejne vrednosti razre­dov so prikazane v legendah na slikah od 7 do 10. Tabela 2. Statistike rastrske karte posplošenih modelskih vrednosti iz modela GROWA–DENUZ in modela DNDC (v kg N/ha). Table 2. Statistics of raster maps of generalized raster map from GROWA–DENUZ and DNDC model (in kg N/ha). Posplošena rastrska karta iz modela GROWA–DENUZ / Generalized raster map from GROWA–DENUZ model Posplošena rastrska karta iz modela DNDC / Generalized raster map from DNDC model Statistike / Statistics Število celic / Number of cells 5.565 5.563 Aritmeticna sredina / Mean 20,37 9,20 Mediana / Mediana 18,69 5,52 Min. vrednost / Min. value 8,68 1,50 Max. vrednost / Max. value 37,05 29,21 Razpon / Range 28,60 27,72 Standardna napaka ocene sredine / Standard error of mean 0,12 0,14 Varianca / Variance 92,37 103,30 Standardni odklon / Standard Deviation 9,61 10,16 Sl, 7. Modelski rezultat DNDC v dvorazredni klasi­ fikacijski shemi. Fig. 7. DNDC model result in two-class classification scheme. Sl. 8. Modelski rezultat GROWA-DENUZ v dvoraz­redni klasifikacijski shemi. Fig. 8. GROWA-DENUZ model result in two-class classification scheme. Sl. 9. Modelski rezultat DNDC v trirazredni klasi­ fikacijski shemi. Fig. 9. DNDC model result in three-class classification scheme. Za oceno ujemanja prostorskih podatkov­nih slojev dveh modelskih simulacij (DNDC in GROWA-DENUZ) in dveh klasifikacijskih shem (dvorazredna in trirazredna shema) smo upora­bili Cohenovo Kappa statistiko (Cohen, 1960) in ArcGIS orodje ocenjevanja zanesljivosti prostor­skih modelov (Jenness & Wynne, 2005). V prime­ru trirazredne klasifikacijske sheme je stopnja zanesljivosti ujemanja 71,7 % s Cohenovim Kap­pa koeficientom 0,57, v primeru dvorazred ne kla­sifikacijske sheme pa je stopnja zanesljivosti uje­manja 89,5 % s koeficientom 0,73, kar se že lahko interpretira kot razred dobrega ujemanja (Lan-dis & Koch, 1977) (Tabela 3) (sl. 7 do 10). Primerjalna analiza rezultatov modeliranja toka dušika preko koreninskega obmocja tal v regionalnem in lokalnem merilu Spodnje Savinj­ske doline odkriva dobra medsebojna ujemanja Tabela 3. Kappa statistike za razlicne klasifikacijske sheme. Table 3. Kappa statistics for different classification scheme. predvsem pri višjih modeliranih vrednostih, to je v velikostnem obmocju nad okoli 23 kg N na hektar. Skoraj popolno ujemanje je ugotovlje­ no za povprecja hidroloških enot s hmeljišci na obrecnih tleh in zelo prepustnem vodonosniku s podzemno vodo plitvo pod tlemi (sl. 7 do 10). Vecja odstopanja pa so bila ugotovljena pri nižjih vrednosti modeliranega dušika pod koreninskim obmocjem, predvsem na obmocju hipoglejev in psevdoglejev. To so obmocja na sever nem obrobju doline z bolj anaerobnimi talnimi pogoji in regi­onalno modeliranimi vrednostmi pod 12 kg N na hektar. Z obsežnimi terenskimi meritvami raz­topljenega kisika v podzemni vodi so bila na teh obmocjih že dokazana izrazita redukcijska oko­lja, pomembna za regionalno porazdelitev nitrata v podzemni vodi (Uhan, 2010, 2011; Uhan et al., 2011). Klasifikacijska shema / Classification scheme KHAT / Kappa statistics Varianca / Variance Z-vrednost (%) / Z-score (%) P Spodnja meja inter vala za­upanja (95 %) / Lower confi­dence interval (95 %) Zgornja meja inter vala za­upanja (95 %) / Upper confi­dence interval (95 %) Ocena za­nesljivosti / Accuracy assessment Dvorazredna klasifi kacijska shema / two­-class classifi­cation scheme 0,73 0,00010 71,87 < 0,00001 0,714 0,754 0,895 Trirazredna klasifi kacijska shema / three­-class classifi­cation scheme 0,57 0,00008 62,60 < 0,00001 0,549 0,584 0,717 Ocenjujemo, da je stopnja denitrifikacije v obmocju korenin v primeru bolj glinastih talnih razmer z nizko vsebnostjo kisika in visoko vseb­nostjo vode, kot tudi visoko vsebnostjo organskih snovi, zaznavno višja, kot jo prikazujejo rezul­tati regionalnega modela. V regionalnem mode­lu GROWA-DENUZ so denitrifikacijski pogoji v tleh Slovenije ocenjeni na podlagi referencnih vrednosti, pridobljenih z meritvami na srednje­evropskih tleh, kar je nedvomno lahko velik vir variacije oz. odstopanja od rezultatov lokalnega modela, ki temelji na raziskanih reprezentativ­nih profilih tal študijskega obmocja. Poleg raz­lik v vhodnih podatkih o gnojenju in kmetijski praksi v obeh modelskih simulacijah lahko tudi v tem išcemo razloge za razlike med povprecnimi vrednostmi obeh modelskih rešitev (Tabela 2). V prihodnje je priporocljivo terensko raziskati ob­mocja z ugodnimi denitrifikacijskimi pogoji in v regionalnem modelu bolj natancno opredeliti po­tencial za redukcijo nitrata v koreninskem obmo­cju in posledicno tudi v podzemni vodi vseh pli­tvih vodonosnikov s slabim kemijskim stanjem. Ob tem pa se je potrebno zavedati, da je proces denitrifikacije modularnega znacaja, kar dodat­no otežuje meritve in modeliranje ter terja raz­širitev raziskav tudi na izotopsko sestavo vode, predvsem na stabilne izotope 18O v NO3 ter 15N in 11B. Znotraj t.i. »izotopskega triptiha« je za raz­likovanje virov nitrata in frakcionacijskih proce­sov, kot je denitrifikacija, pomembno poznavanje predvsem izotopske sestave 11B, na katero bioge­okemijski transformacijski procesi ne vplivajo (Widory et al., 2013; Van Groenigen et al., 2015). Sklep Zaradi odsotnosti dolgorocnega trenda izbolj­ševanja stanja voda po oceni Evropske komisije nitrat v podzemni vodi še vedno predstavlja resno grožnjo okolju na regionalni in lokalni ravni. Re­gionalna modelska simulacija toka nitrata preko koreninskega obmocja v vodonosnik je pomem­ben pristop ocenjevanja ucinkovitosti nacrtova­nih ukrepov zmanjšanja tveganja za onesnaženje podzemne vode, predvsem v primerih intenzivne­ga kmetovanja na plitvih prepustnih vodonosni­kih s slabim kemijskim stanjem podzemne vode in regionalnimi vodooskrbnimi viri. V porocilu na podlagi evropske direktive Sveta 91/676/EEC, ki se nanaša na varstvo voda pred onesnaženjem z nitrati iz kmetijskih virov za obdobje 2012-2015, je Slovenija tovrstni modelski pristop že napove­dala. Ob tem pa je pomembno poznavanje omeji­tev modelskega sistema in zanesljivosti modelskih rezultatov. Z rezultati lokalnega modela DNDC smo podprli analizo vrednotenja rezultatov regi­onalnega modeliranja izpiranja dušika na obmo­cju celotne države. Primerjalna analiza rezulta­tov modeliranja v regionalnem merilu z rezultati modeliranja v reprezentativnih profilih tal je ena od pomembnih stopenj v procesu preizkušanja modela oz. ocenjevanja zanesljivosti rezultatov regionalnih modelov. Primerjalna analiza je na tej stopnji potrdila primernost uporabe rezulta­tov regionalnega modelskega sklopa GROWA­-DENUZ v procesu priprave ukrepov potrebnega zmanjšanja obremenitev na nivoju vodnih teles s slabim kemijskim stanjem podzemnih voda, ob tem pa je izpostavila potrebo po boljši karakte­ rizaciji denitrifikacijskih pogojev po posameznih delih vodnih teles, kar lahko izboljša napovedo­ vanje ucinkov ukrepov tudi v nižjem velikostnem razredu vsebnosti nitrata v vodi pod koreninskim obmocjem tal. Literatura Andjelov, M., Kunkel, R., Uhan, J. & Wendland, F. 2014: Determination of nitrogen redu­ction levels necessary to reach groundwa­ter quality targets in Slovenia. 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CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.016 Korespondenca med Vasilijem Vasilijevicem Nikitinom in Vladimirjem Ivanovicem Vernadskim Correspondence between Vasily Vasilyevich Nikitin and Vladimir Ivanovich Vernadsky Mihael BRENCIC Oddelek za geologijo, Naravoslovnotehniška fakulteta, Univerza v Ljubljani, Aškerceva cesta 12, SI-1000 Ljubljana, Slovenja; e-mail: mihael.brencic@ntf.uni-ljs.si Geological Survey of Slovenia, Dimiceva ulica 14, SI-1000 Ljubljana Prejeto / Received 1. 10. 2018; Sprejeto / Accepted 22. 10. 2018; Objavljeno na spletu / Published online 20. 12. 2018 Kljucne besede: geokemija, biogeokemija, znanstvena korespondenca, izmenjava znanstvene literature, prepis pisem, Slovenija, Rusija Key words: geochemistry, biogeochemistry, scientific correspondence, exchange of scientific literature, transliteration of letters, Slovenia, Russia Izvlecek V clanku je predstavljeno dopisovanje med mineralogom, petrologom in strokovnjakom za kovinske mineralne surovine, rudarskim in ženir jem Vasilijem Vasilijevicem Nikitinom (1867-1942) in znamenitim r uskim geologom, mineralogom, geokemikom in filozofom Vladimirjem Ivanovicem Vernadskim (1863-1945). V Arhivu Ruske Akademije znanosti v korpusu arhivskega gradiva o Vernadskem je ohranjenih šest dopisov Nikitina Vernadskemu, ki so v clanku prevedeni, dokumentirani in kriticno interpretirani. V omenjenem arhivu sta Nikitinu pripisani še dve pismi, za kateri pa smo dokazali, da nista njegovi. Korespondenca dokazuje, da je Nikitin tudi po prihodu v Ljubljano ohranjal stike s svojim nekdanjim delovnim okoljem v Rusiji, hkrati pa je to dokaz, da so si prvi profesorji, ki so poucevali na Univerzi v Ljubljani, intenzivno prizadevali za stik z razvojem znanosti po svetu. Abstract The article presents the correspondence of mineralogist, petrologist and mineral resource expert mining engineer Vasily Vasilyevich Nikitin (1867-1942) with the famous Russian geologist, mineralogist, geochemist and philosopher Vladimir Ivanovich Vernadsky (1863-1945). In the Archive of the Russian Academy of Sciences in the corpus of Vernadsky’s archival material, six letters of Nikitin to Vernadsky have been preserved. In the paper they are translated, documented and critically interpreted. In the archive, two other letters are also attributed to Nikitin, but we have proved that they are not his. The correspondence proves that after joining University of Ljubljana, Nikitin maintained contact with his former working environment in Russia, and at the same time it is a proof that the first professors who taught at the University of Ljubljana have sought contact with the development of science around the world. Uvod nobena izjema. Mnogo redkeje bomo naleteli na Starejša pisma predstavljajo izjemno zgodo-korespondenco znanstvenikov in raziskovalcev, vinsko gradivo. Nudijo nam vpogled tako v inti-zlasti naravoslovcev; in tehnikov. Takšne objave mne odnose med dopisovalci kot tudi v znacilnosti in kriticne analize tega gradiva so prej izjema kot obdobja, v katerem so pisma nastala. Nemalokrat pravilo, ne le v slovenšcini, temvec tudi v drugih nam posredujejo podatke, ki se v drugem ar-jezikih. V slovenskem jeziku je kriticnih izdaj pi­hivskem gradivu niso ohranili, ali pa so pisma sem slovenskih naravoslovcev ali tujcev, ki so de­kot dokument zanimiva sama po sebi. Zlasti v lovali na slovenskem ozemlju, zelo malo. Izjema je literarni znanosti bomo našli številne kriticne korespondenca Antonija Scopolija z Linéjem (So­izdaje pisem pomembnih literatov in njihovih do-ban, 2004) ter korespondenca Žige Zoisa (Kidric, pisnikov, pri tem slovenska literarna znanost ni 1939; 1941). Predvsem korespondenca slednjega je podrobno obdelana, zaradi njegovega velikega pomena za slovenski narodni preporod ter zaradi njegove mecenske vloge pri porajajoci se sloven-ski literaturi. V Zoisovi korespondenci naletimo tudi na naravoslovno pomembne informacije. Pisemsko dopisovanje je bilo dolga stoletja pomemben nacin komunikacije. Zlasti med iz­obraženci in intelektualci so bila pisma medij, s katerim so si sporocali številne informacije ter razmišljanja. Nemalokrat so bila pisma pravi znanstveni ali literarni clanki, ki so jih avtorji ali prejemniki zbrali in nato objavili v knjigah. Neka­tere med temi knjigami so bile zelo brane in pogos­to ponatisnjene. Žal je takšen nacin dopisovanja z razvojem sodobne tehnologije zamrl, in vprašanje je, koliko današnjega intenzivnega elektronskega dopisovanja se bo ohranilo zanamcem. Ce so v splošni zgodovini, še zlasti pa v lite­rarni zgodovini, pisma pomemben vir za pre-ucevanje, v zgodovini naravoslovnih znanosti ni tako. Pred zgodovino naravoslovja je na tem podrocju še veliko dela. Sistematicno zbranih pi­semskih zbirk v svetovni literaturi skorajda ni. Izjema so le najpomembnejši znanstveniki, kot sta Albert Einstein in Isaac Newton, toda tudi v njunem primeru zbirke pisem še vedno niso obja­vljene v celoti. Nekoliko bolje so se pri tem odre­zali znanstveniki, ki so v preteklosti delovali na podrocju današnje Rusije, a so te zbirke pisem za ner usko govorece in pišoce raziskovalce skorajda nedostopne. Obstoj zbirk ruskih naravoslovnih korespondenc je tudi vzrok za odkritje pisem, ki jih predstavljamo v clanku. Vasilij Vasilijevic Nikitin je bil rudarski inže­nir, v svojem casu mednarodno znan in uveljav­ljen mineralog in petrolog, strokovnjak za mine­ralogijo rud, ki je po Oktobrski revoluciji zapustil Sovjetsko zvezo in se je proti koncu svoje kariere zatekel na Tehnicno fakulteto novoustanovljene Univerze v Ljubljani, kjer je vse do svoje smrti skrbel za izobrazbo prihodnjih inženirjev geolo­gije in rudarstva (sl. 1). Znano je, da je že v casu svojega dela na Rudarskem inštitutu v Peterbur­gu imel številne stike z raziskovalci po celem sve­tu, te stike pa je vzdrževal tudi po svojem prihodu v Ljubljano. Žal je ta korespondenca izgubljena, bolj ali manj po nakljucju se je ohranil le del nje­govega dopisovanja z Vladimirjem Ivanovicem Vernadskim, ruskim geologom, geokemikom in filozofom svetovnega slovesa, katerega najzname­nitejše delo je knjiga Biosfera. Ruska zgodovina znanosti Vernadskega postavlja ob bok Einsteinu in drugim najpomembnejšim znanstvenikom 20. stoletja. Že iz tega razloga je korespondenca med obema znanstvenikom pomembna, toliko bolj zato, ker moramo Nikitina obravnavati kot enega od zacetnikov sodobne geološke znanosti v Slove­niji. V clanku je predstavljen transkript in slo­venski prevod šestih Nikitinovih pisem Vernad­skemu. Pisma so komentirana in interpretirana. Objavljena so le Nikitinova pisma, odgovorov Vernadskega na Nikitinova pisma ne poznamo. Nikitinov arhiv je verjetno v celoti izgubljen, saj je umrl leta 1942, sredi vojne vihre. Iz ohranjene­ga pisemskega gradiva lahko sklepamo le, da je bila korespondenca med obema znanstvenikoma obojesmerna. Življenjepisa Preden se podrobneje lotimo prevodov pisem in komentarjev, si na kratko oglejmo življenjepisa in znanstvene dosežke obeh korespondentov. Vasilij Vasilijevic Nikitin se je rodil 18. mar­ca 1867 v Sankt Peterburgu, v tedanjem Ruskem imperiju. Leta 1886 je maturiral na klasicni gim­naziji in se vpisal na fizikalno-matematicni od­delek Petrograjske univerze, vendar je po sedmih mesecih študija prestopil na Rudarski inštitut, ki je imel status visoke rudarske šole. Kot rudarski inženir je leta 1895 diplomiral, vendar kasneje stopnje akademskega doktorata ni nikoli dosegel. Raziskovalno delo je zacel že kot študent, kmalu pa se je zaposlil na svojem maticnem inštitutu. Sodeloval je pri intenzivnih geoloških raziska­vah v Sibiriji, na Uralu ter v okolici Moskve. Leta 1917 je postal tudi direktor Rudarskega inštitu­ ta, vendar je že leta 1919 zaradi težkih delovnih razmer odstopil. Izselil se je na Poljsko, vendar se je leta 1920 vrnil v Peterburg in nato do leta 1922 pouceval na Rudarskem inštitutu. Leta 1923 je zaprosil za dovoljenje za izselitev in ga tudi dobil, skupaj z ženo sta se preselila na njeno poljsko posestvo. Od tod je leta 1925 na povabi­lo prof. Karla Hinterlechnerja odšel v Ljubljano, kjer je zacel poucevati predmete s podrocja mi­neralnih surovin na Univerzi v Ljubljani. Na njej je pouceval vse do svoje smrti leta 1942 (Duhov­nik, 1953). Nikitin je bil plodovit avtor, napisal je vecje število strokovnih in znanstvenih clan­kov, obsežen nabor študijskega gradiva ter tudi knjig, ki so izšle pri takrat pomembnih znanstve­ nih založbah, prevedene pa so bile v vec jezikov. Bil je velik strokovnjak za metodo Fedorova, to je posebnega nastavka petrografskega mikrosko­ pa, s katerim so se dolocale znacilnosti kristalov. Nastavek je bil sestavljen iz vrtljivih mizic, ki so bile vgnezdene druga v drugo, na njih pa so bile vgravirane številke z oznakami kotov. To je omo­ gocalo odcitavanje opticnih znacilnosti kristalov pod razlicnimi koti. Njegovo znanje na tem po­drocju je bilo tako pomembno, da so se k njemu v Ljubljano prihajali šolat številni evropski mine­ ralogi in kristalografi. Vladimir Ivanovic Vernadski (sl .2) se je rodil 12. marca 1863 v Sankt Peterburgu profesorju politicne ekonomije, ki je bil po poreklu iz Ukra­jine. Osnovno znanje je pridobil v rodnem mes­tu, prav tako pa je tam leta 1885 diplomiral na Državni peterburški univerzi. Kmalu po diplo­mi je, išcoc snov za doktorat, odpotoval v Italijo, Francijo in Nemcijo. Usmeril se je predvsem v mineralogijo, kristalografijo in uporabo teh ved v pedologiji. Leta 1889 je doktoriral in pocasi zacel širiti podrocje svojega znanstvenega delo­vanja. Dokaj kmalu se je angažiral tudi na poli­ticnem podrocju in bil leta 1905 tudi clan prve demokraticne državne Dume. V casu Oktobrske revolucije je odšel na Krim ter nato v tujino, ven­dar se je nato vrnil v domovino. V obdobju let 1922 do 1926 je kot gostujoci profesor predaval na Sorboni v Franciji. Ves cas svojega izredno plodovitega in delovnega življenja, vse do smrti 6. januarja 1945 v Moskvi, je bil izredno ustvar­jalen. S svojim delom je posegel na številna pod­ rocja znanosti. Ukvarjal se je tako z osnovnimi geološkimi vedami, kot so mineralogija, geo­kemija, radiogeologija, pedologija in rudna ge­ ologija, kot tudi s filozofijo, politicno mislijo in zgodovino znanosti. Bil je izjemen organizator znanosti, ustanovil je številne muzejske zbirke in raziskovalne inštitute, nekateri med njimi de­lujejo še danes, zaslužen je bil tudi za organi­zacijo številnih znanstvenih odprav po obsežnih prostranstvih Sovjetske zveze. Njegovo najzna­menitejše delo je knjiga Biosfera, ki je prevede­na v številne svetovne jezike. Knjiga obravnava biosfero kot dejavnik preoblikovanja Zemlje in cloveka kot geološki dejavnik. To njegovo delo je dobro znano tudi na zahodu, medtem, ko so nekatera druga njegova dela, zaradi tega, ker so dostopna le v rušcini ali pa v zelo okrnjenih pre­vodih, manj znana. Njegova zbrana dela obsega­ jo štiriindvajset knjig in locene zbirke pisem. Prevod pisem Vir pisem Originali pisem so v Arhivu Ruske akademije znanosti (Arhiv RAZ) v Moskvi. Dopisnico, ki jo je Nikitin napisal Vernadskemu leta 1915, je konec leta 2016 avtor clanka po nakljucju našel na in­ternetni strani Arhiva RAZ. Žal internetna stran, na kateri je bilo najdeno pismo, v casu priprave clanka ni vec aktivna. Na tej strani je bil predsta­vljen zelo obsežen arhiv korespondence Vernad­skega s številnimi sodobniki, nekatera od pisem so bila na voljo tudi v faksimilni obliki. V kazalu arhiva pisem je bil kot dopisnik Vernadskega na­veden tudi Vasilij Vasilijevic Nikitin. Poleg ome­njenega faksimila je bil pripet še kataložni listek (sl. 3), iz katerega je bilo razvidno, da je v arhivu ohranjena tudi druga Nikitinova korespondenca. Na listku so nanizana leta, v katerih je bila pos­lana ohranjena korespondenca (leta 1915, 1921, 1926, 1927 in 1930) in kraj, od koder je bila posla­na (Petrograd in Ljubljana). To je nakazovalo, da sta imela dopisovalca pismeni stik tudi po tem, ko je Nikitin že prevzel mesto univerzitetnega profe­sorja na Univerzi v Ljubljani. To odkritje je bilo spodbuda za nadaljnje iskanje kopij pisem. Avtor clanka je v letih 2016 in 2017 veckrat skušal navezati stik z Arhivom RAZ, vendar ne­uspešno. Šele pomoc avtorjevih znancev v Mo­skvi je pripeljala do tega, da so mu bili decembra 2017 po elektronski pošti posredovani faksimili ostalih ohranjenih pisem. Vendar pri tem težav s korespondenco še ni bilo konec. Izkazalo se je, da je Nikitinov rokopis izredno težko citljiv. Za prepis pisem je bilo treba najti nekoga, ki je vešc branja težko citljivih ruskih rokopisov. Rokopi­su pisem niso bili kos niti avtorjevi znanci, ki so naravni govorci sodobne rušcine. Prepis pisem je v maju 2018 opravila Tatiana M. Dianova sode­lavka Geografske fakultete Moskovske državne univerze - MGU. Kljub temu so nekatere besede ostale neprebrane. Na teh mestih je bila glede na kontekst besedila podana najverjetnejša beseda ali pa je bila ta rekonstruirana s pomocjo drugih virov. V okviru prepisa ruskega besedila pisem ni bil opravljen prepis neruskih delov pisem. Ta del besedila je rekonstruiral avtor clanka sam s pomocjo bibliografije del Vernadskega, ki so jo pripravili Bebih in sodelavci (1992). Pri pripravi clanka so bile na voljo le kopije pisem (skeni v elektronski obliki), zaradi tega njihovega pravega formata in velikosti ne pozna­mo. Na obliko in format pisma lahko sklepamo le iz posnetka pisma. Vsaka stran pisma je bila posredovana v svoji slikovni datoteki. Pri neka­terih pismih ni bilo jasno, kateremu pismu pripa­da dolocen naslov, zato je bilo treba opraviti tudi usklajevanje naslova in besedila. Kot ilustracijo podajamo le posamezne kopije pisem. Izhodišca Pisma Nikitina Vernadskemu so v Arhivu RAZ v fondu št. 518, inventar št. 3, pod tekoco številko 1154. Skupaj je bilo iz arhiva posredo-vano 18 posnetkov (skenov) ki sestavljajo 8 enot korespondence. Prva enota korespondence je do­pisnica datirana z datumom 2. XII. 1915 in zad­nja enota je dopisnica datirana z datumom 29. XI. 1930. Skrbna analiza in primerjava besedil z življenjepisom Nikitina ter medsebojna primerja­va rokopisov so pokazali, da sta v arhivu 2 eno­ti korespondence, ki ne pripadata Vasiliju Vasi­ lijevicu Nikitinu, mineralogu in petrologu, ki je deloval v Ljubljani. Pripadata V. Nikitinu, ki je deloval na raziskovalni postaji Akademije v Se­ vastopolu na krimski obali Crnega morja. O tem avtorju nam ni znanega nicesar. Ceprav je bil prepis teh pisem narejen, njihovega prevoda ne podajamo. Ta pisma so povzeta na kratko, pred­vsem z namenom dokazovanja, da v primeru obeh Nikitinov ne gre za isto osebo. V nadaljevanju podajamo prevode posame­znih enot korespondence. Za vsako enoto so pov­zete osnovne informacije o naslovniku in obliki dopisa. Sledi prevod enote in nato komentarji ter opombe. Pisma so nanizana v kronološkem zapo­redju. Prevodi pisem Pismo 1 Vrsta dopisa: dopisnica. Odposlano: iz Petro­grada. Naslov: Tukaj. Carska akademija znano­sti. Geološki muzej; njegovemu prvopredpostav­ljenemu Vladimirju Ivanovicu Vernadskemu. Datum: 2. XII. 1915. Prevod besedila Nadvse spoštovani Vladimir Ivanovic Z obžalovanjem vam sporocam, da zaradi po­manjkanja casa ne bom sodeloval na današnjem zasedanju komisije. Nadvse se vam zahvaljujem za vaš cas, ki ste ga potratili s pisanjem vabila. S spoštovanjem VNikitin Opombe Vernadski je bil leta 1913 izbran za direktorja Geološkega in mineraloškega muzeja Akademije znanosti in umetnosti. V casu, ko je bila napisa­na dopisnica, je v vlogi direktorja vodil številne znanstvene in strokovne komisije, zato ni možno ugotoviti, za katero komisijo je Nikitin dobil va­bilo. Pismo 2 Vrsta dopisa: pismo na pisemskem papirju. Odposlano: neznano. Naslov: Vladimirju Ivano­vicu Vernadskemu od Nikitina Datum: 16. XI. 1921. Prevod besedila Nadvse spoštovani Vladimir Ivanovic Upoštevajoc vašo naklonjenost, se na Vas ob­racam z veliko prošnjo, da bi me oskrbeli z dru­gim delom vaših »Vaj iz splošne mineralogije«. Vse najboljše s spoštovanjem VNikitin Opombe Gre za delo ».... ............. ............ .. 2. ......... . .......... ..........« (Vaje iz splošne mineralogije, drugi del, žveplovi in se­lenovi minerali), ki je izšlo leta 1918. V casu na­stanka tega pisma sta se oba korespondenta že vrnila v Peterburg. Nikitin iz Poljske, kamor se je zatekel leta 1919 (Duhovnik, 1953) in Vernadski s Krima, kjer je v letih 1920 – 1921 opravljal funk­cijo rektorja Tavrijske univerze v Simferopolu (Bebih et al., 1992). Pismo 3 Vrsta dopisa: dopisnica. Odposlano: iz Lju­bljane. Naslov: A kademiku Vladimir ju Ivanovicu Vernadskemu, Geološki muzej Akademije znano­sti, Leningrad. Rusija. Pošiljatelj: V.V. Nikitin, Mineraloški inštitut Univerza v Ljubljani, Jugo­slavija. Datum: 17. VIII. 1926. Prejeto: 24. VIII. 1926. Prevod besedila Nadvse spoštovani Vladimir Ivanovic Po daljši prekinitvi sem se v vlogi kontraktu­alnega rednega profesorja mineralogije in petro­logije na Tehnicni fakulteti Ljubljanske Univerze ponovno vrnil k prejšnjim dejavnostim. V Mi­neraloškem inštitutu, katerega direktor je prof. Hinterlechner, imam na razpolago dovolj opre­me, ki mi omogoca dokaj dobro nadaljevanje mo­jega dela. Ce vzamemo v obzir mladost univer­ze, v knjižnici ni veliko periodicnih in avtorskih publikacij. Zelo pog rešam r usko literaturo. Bil bi zelo hvaležen, ce bi si lahko ustvaril vtis o vašem delu. S sprejemom na univerzi in v sami Ljublja­ni v celoti sem zelo zadovoljen. Vse najboljše. S spoštovanjem. VNikitin. Opombe Zaradi nejasnih poštnih žigov je pri dataciji tega dopisa nekaj težav. Glede na vsebino je bilo poslano pred naslednjim pismom (pismo 4). Niki­tin se je leta 1926 zaposlil na Tehnicni fakulteti Univerze v Ljubljani. Ker je imel pogodbo o za­poslitvi le za dolocen cas, je nosil naziv pogod­benega ali kontraktualnega profesorja s placo in položajem rednega profesorja. V Ljubljano je pri­šel na povabilo profesorja Hinterlechnerja, ki je bil v tem casu rektor Univerze v Ljubljani. Pismo 4 Vrsta dopisa: dopisnica. Odposlano: iz Lju­bljane. Naslov: Akademiku V ladimir ju Ivanovicu Vernadskemu, Geološki muzej Akademije znano­sti, Leningrad. Rusija. Pošiljatelj: V.V. Nikitin, Mineraloški inštitut Univerza v Ljubljani, Jugo­slavija. Datum: 10. X. 1926. Prejeto: 16. X. 1926. Prevod besedila Nadvse spoštovani Vladimir Ivanovic Najlepše se zahvaljujem za pošiljko vaših del. Dobil sem: -O vodikovih mineralih. -O psevdomorfozi curita. -O analizi tal z vidika geokemije. -O kemijski sestavi živih bitij v odvisnosti od kemizma zemeljske skorje. -Vpliv toplote na kaolinit in kaolinitne gline. -Zapisi o preucevanju živih organizmov z vidika geokemije. -Mendeljevit, nov radioaktiven mineral. -O razmnoževanju organizmov in njegovem pomenu v mehanizmih biosfere. -Biogeokemijske razprave. O hitrosti spre­minjanja življenja v biosferi. Prirod in izdaj v vrstici 27 v naši knjižnici ni. Vaša mineralogija - dopolnjeni drugi del tretje izdaje iz leta 1912. Zahvaljujem se vam za ob­vestilo o izidu nove izdaje. Uporabljam dopol­nitve te izdaje. Prof. Hinterlechner se zahvaljuje za pošiljko in na naslov Muzeja pošilja svoja dela. Seveda v zameno ne bom uspel poslati svojih prvih del. Še enkrat se vam zahvaljujem. Ali ste dobro? Še posebno, ugodni pogoji za delo ... Vaš VNikitin Opombe Pismo predstavlja odgovor na obsežnejšo po­šiljko prispevkov Vernadskega, ki jih je ta poslal Nikitinu na podlagi prošnje, posredovane z dopi-snico dne 17. VIII. 1926. Novo nastalo Univerzo v Ljubljani je pestilo veliko pomanjkanje znan­stvene in strokovne literature. Pri tem profesorja Nikitin in Hinterlechner, ki sta delovala na Teh­niški fakulteti, nista bila nobeni izjemi. Profe­sorji so si pri nabavi prepotrebnega gradiva po­ magali na razlicne nacine, ne nazadnje tudi tako, da so prosili za kopije razlicnih del in separate clankov. To je bil nekoc ustaljen nacin izmenja­ve znanstvene literature. Tako je Nikitin, kmalu po prihodu v Ljubljano, izkoristil svoje znanstvo z Vernadskim, da bi mu ta posredoval cim vecje število svojih del. V pismu se mu zahvaljuje za posredovano literaturo in pri tem našteva, katera dela je prejel. Oglejmo si, kdaj in kje so v pismu našteta dela Vernadskega izšla. Dela so navedena v zapored­ju, kakor so našteta v pismu. Delo »O vodikovih mineralih« je izšlo kot kratek clanek v rušcini pod naslovom ». .......... .........« v reviji ........ ... (Prispevki Ruske akademije zna­nosti -april/junij 1924; 74-76). Delo »O psevdo­morfozi curita« je izšlo v Parizu v francošcini pod naslovom »Sur une pseudomorphose de la curi­te« v publikaciji Comptes rendus de l‘Académie des Sciences (vol. 178; 1726-1728). Tudi naslednje delo »O analizi tal z vidika geokemije« je clanek, ki je izšel v francošcini z naslovom »Sur l’analy­se des sols au point de vue géochimique«. Delo je izšlo v zborniku 4. mednarodnega pedološkega kongresa v Rimu (Acte de la IV Conférence in­ternationale de pédologie), ki je potekal v maju 1924, zbornik pa je izšel šele leta 1926 (vol 2., 570-577). Clanek »O kemijski sestavi živih bitij v odvisnosti od kemizma zemeljske skorje« je izšel leta 1925 v Pragi v cešcini z naslovom »O che­mickém složeni žive hmoty v souvislosti s chemii kury zemské« Sbornik pri´roda - Ceska´ Akademie Ved a Umeni (zv. 1-16). Clanek »Vpliv toplote na kaolinit in kaolinitne gline« je prispevek, ki je bil objavljen v anglešcini leta 1925 pod naslovom »The Action of Heat on Kaolinite and on Kaolini­te Clays« v publikaciji Transactions of Cerami­cal Society (vol. 24, 13-22). Clanek »Zapisi o pre-ucevanju živih organizmov z vidika geokemije« je izšel leta 1921 v rušcini (....... .. ........ ...... ........ . .............. ..... ......) v publikaciji ........ ... (Izvestija Ruske aka­demije znanosti – serija 6, vol. 15, 43-44). Clanek »Mendelejevit, nov radioaktivni mineral« je izšel v francošcini (Le mendéléjévite, nouveau minéral radioactif) leta 1923 v reviji Comptes rendus de l‘Académie des Sciences (vol. 176; 993-994). Cla­nek »O razmnoževanju organizmov in njegovem pomenu v mehanizmih biosfere« je izšel v r ušcin i (. ........... .......... . ... ........ . ......... ........) leta 1926 v reviji ........ .. .... (Izvestija Akademije znanosti SSSR – serija 6, vol. 20, zv. 9, 697-726 in vol. 20, zv. 12, 1053-1060). Delo »Biogeokemijske razprave. O hitrosti spreminjanja življenja v biosferi« je izšlo v francošcini (Études biogéochimiques. 1. Sur la vitesse de la transmission de la vie dans la bio­sphère) leta 1926 v reviji ........ .. .... (Iz­ vestija Akademije znanosti SSSR – serija 6, vol. 20, zv. 9, 727-744). Vecina teh del je bila v knjižni­ci Oddelka za geologijo tudi katalogizirana, žal so bila v casu obnove knjižnicnih prostorov leta 2017 vsa izlocena in odpisana ter unicena. Zaradi tega ni mogoce ugotoviti, ali so bila na separatih zapisana kakšna posvetila ali celo kakšna daljša pojasnila. Iz Nikitinovega pisma izhaja, da mu je Ver­nadski poleg separatov del posredoval tudi pis­mo, v katerem našteva, kaj pošilja. Na to lahko sklepamo iz omembe vrstice 27, v kateri Nikitin omenja revijo Priroda. Vernadski mu je verjetno odpisal, da si lahko nekatere njegove clanke pre­bere tudi v reviji Priroda. Vendar Nikitin odgo­varja, da v knjižnici Prirode ni. Za katere clan­ke Vernadskega pri tem gre, ni mogoce natancno ugotoviti. Verjetno gre vsaj za clanek »Potek živ­ljenja v biosferi« z ruskim naslovom »... ..... . ........«, ki je izšel leta 1925 (....... – Priro­da vol. 10, zv. 12; 25-38). V Nikitinovem pismu je omenjen tudi ucbe­nik mineralogije. Tretja dopolnjena in prede­lana izdaja tega ucbenika je izšla že leta 1912 (...........; izdala založba ....... ........). Ali sta imela dopisovalca v mislih kakšen kasnej­ši natis, saj je med izdajo ucbenika in njunim do­pisovanjem poteklo že štirinajst let, na podlagi razpoložljivih podatkov ni mogoce ugotoviti. Pismo 5 Vrsta dopisa: dopisnica. Odposlano: iz Lju­bljane. Naslov: Akademiku Vladimirju Ivanovi­cu Vernadskemu, Mineraloški muzej Akademije znanosti, Leningrad. Rusija. Pošiljatelj: V. Niki­tin, Mineraloški inštitut Univerza, Jugoslavija. Datum: 9. V. 1927. Prejeto:. 17. V. 1927 (najverje­tnejša datacija) Prevod besedila Nadvse spoštovani Vladimir Ivanovic Iskreno se vam zahvaljujem za pošiljko vaših zanimivih del: O razpršitvi kemijskih elementov, Mnenje o sodobnem pomenu zgodovinskega živ­ljenja in živi snovi ter O razmnoževanju organiz­mov in njegovem pomenu v mehanizmih biosfere. Vse najboljše. VNikitin Opombe Tudi v tem primeru gre za dopisnico, v kateri se Nikitin zahvaljuje za prejeto pošiljko. Ali je, pred tem poslal Nikitin prošnjo za omenjena dela nam ni znano. Vsa tri posredovana dela so izšla v rušcini. Delo »O razpršitvi kemijskih elementov« (. ......... .......... .........) je izšlo leta 1927 kot priloga k Porocilu o dejavnosti A kademi­je znanosti – Splošno porocilo za leto 1926 (..... . ............ ........ .... .. 1926: ...... .....; 1-15). Delo »O razmnoževanju organizmov in njegovem pomenu v mehanizmih biosfere« je Nikitin prejel že leta 1926, saj je njegov prejem Vernadskemu potrdil že z dopisnico z dne 10. X. 1926 (glej pismo 4). Poleg tega je zanimivo, da dela »Mnenje o sodobnem pomenu zgodovinske­ga življenja in živi snovi« (...... . ........... ........ ............. ..... . ..... ........) v nobeni od razpoložljivih bibliografij Vernad­skega ni mogoce najti, prav tako ni bilo zavedeno v kataložnih listkih knjižnice Oddelka za geolo­gijo. Verjetno je Nikitin napacno napisal naslov. Pismo 6 Vrsta dopisa: dopisnica. Odposlano: iz Lju­bljane. Naslov: Akademik V.I. Vernadski, Bioge­okemijski laboratorij Akademije znanosti, Le­ningrad. Rusija (USSR). Pošiljatelj: V. Nikitin, Mineraloški inštitut Univerza, Ljubljana, Jugo­slavija. Datum: 29. IX. 1930. Prejeto: neznano. Prevod besedila Nadvse spoštovani Vladimir Ivanovic Z iskrenim zadovoljstvom vam sporocam, da sem prejel pošiljko prve izdaje Prispevkov bioge­okemicnega laboratorija in Vašega clanka »Vseb­nost radija v naravnih vodah«. Vse najboljše! VNikitin Opombe Ali je Vernadski Nikitinu posredoval neka­tere zvezke publikacije Prispevki biogeokemic­nega laboratorija (..... ................. ...........) ali pa le posamezni separat clanka, ni mogoce ugotoviti. Glede na nacin pošiljanja separatov s strani Vernadskega v letih pred tem lahko domnevamo, da je bil posredovan le en cla­nek. Vernadski je leta 1928 laboratorij ustanovil in ga vodil vse do svoje smrti leta 1945. Morda Sl. 5. Kopija naslovni­ce dopisnice, poslane iz Ljubljane 29. IX. 1930 (pis­mo 6). je Nikitin zapisal, da je prejel publikacijo zaradi tega, ker je dobil celoten izvod, saj je ta zacela izhajati prav v letu 1930. Vernadski je v tem letu v tej publikaciji objavil clanek »Splošni premisleki o študiju kemijske sestave žive materije«, ki je iz­šel v francoskem jeziku (Considérations généra­les sur l’etude de la composition chimique de la matière vivante - ..... ................. ...........; vol.1, 5-32). Dr ugi clanek, ki ga na­vaja Nikitin, je prav tako izšel v francošcini in sicer v Parizu v reviji Comptes rendus de l‘Acadé­ mie des Sciences (vol. 190; 1172-1175). Pisma, pripisana Vasiliju Vasilijevicu Nikitinu Poleg zgoraj prevedenih in komentiranih pi­sem sta v Arhivu RAZ še dve pismi, ki sta pripisa­ni Vasiliju Vasilijevicu Nikitinu in sta podpisani s podpisom VNikitin. Prvo pismo je bilo odposla­no dne 18. II. 1921 in drugo 25. VI. 1926. Obe sta napisani na listih, iztrganih iz šolskega zvezka s crtami. Od kod so bila pisma odposlana, ni nave­deno, iz vsebine pa lahko sklepamo, da je bil pisec v Sevastopolu na Krimu, kjer je vodil in upravljal raziskovalno postajo za raziskave Crnega morja pod okriljem RAZ. V pismih pisec Vernadskemu sporoca o težavah, s katerimi se mora soocati pri upravljanju postaje in raziskavah, ki so jih izvaja­ li. Iz biografije Vasilija Vasilijevica Nikitina (Du­hovnik, 1953) in njegovega življenjepisa izhaja, da se z raziskavami morskih sedimentov ni ukvarjal, poleg tega je bil v letih 1921 in 1926 na Poljskem, v Petrogradu in nato v Ljubljani. S tega razloga pisem ni mogel napisati on. Ti dve pismi sta v fond pisem Vasilija Vasilijevica Nikitina verjetno uvršceni zaradi izredno podobnega rokopisa obeh piscev pisem, ki sta se za namecek še oba podpi­sovala z zelo podobnim podpisom VNikitin. Avtor clanka je skušal identiteto tega drugega pisca pi­sem preveriti, vendar je priimek Nikitin izredno pogost ruski priimek in ugotavljanje, kdo je avtor drugih dveh pisem s podpisom VNikitin, bi terja­ lo izredno veliko casa. Glede na vsebino pisem pa je ocitno, da ne gre za istega avtorja, zato smo to vprašanje pustili nerešeno. Razprava V arhivu Ruske akademije znanosti v Moskvi se je ohranilo šest enot korespondence, ki jih je Vasilij Vasilijevic Nikitin poslal Vladimirju Iva­novicu Vernadskemu. Dve, najstarejši enoti ko­respondence sta bili odposlani iz Peterburga, preostale štiri pa so bile poslane iz Ljubljane v Sankt Peterburg, tedanji Leningrad. Pisma, ki jih je pošiljal Vernadski Nikitinu, nam za sedaj ostajajo neznana. Velika verjetnost je, da tudi vsa Nikitinova pisma Vernadskemu niso ohranjena. Iz vsebine Nikitinovih dopisov nedvomno izhaja, da je bilo dopisovanje med obema znanstveni­koma obojesmerno in v obdobju po Nikitinovem prihodu v Ljubljano tudi nekoliko intenzivnejše. Ceprav sta se dopisnika osebno poznala, saj iz dopisnice, poslane v letu 1915, izhaja, da sta v Peterburgu sodelovala v istih delovnih telesih, je njuna korespondenca zelo formalna. Vecina be­sedila dopisov je posvecena seznamom znanstve­ne literature in potrditvi prejema pošiljk. Kljub temu iz pisem razberemo nekaj osebnih informa­cij. Nikitin v prvem pismu iz leta 1926 (pismo 3) poroca, da je prispel v Ljubljano in v kakšnih po­ gojih deluje, pritožuje se tudi nad pomanjkanjem literature in prosi Vernadskega za kopije njego­vih znanstvenih del. V naslednjem pismu se, sicer skopo, sprašuje o pogojih, v katerih dela Vernad­ski. Iz zapisanega izhaja, da so ta vprašanja zapi­sana zelo previdno, skorajda, kot da bi spraševal med vrsticami. Tudi te besede dokazujejo, da sta se oba dopisnika poznala vec kot zgolj formalno. Ali mu je na ta vprašanja Vernadski kaj odgovo­ril, nam ostaja neznano. Vzrok za rezerviranost Nikitina izhaja iz dej­stva, da se je zavedal, da mora biti kot politicni emigrant pri dopisovanju s svojimi znanci v Ru­siji zelo previden, ne glede na to, da je bil položaj Vernadskega v Rusiji privilegiran, saj je bil eden redkih državljanov SSSR, ki je lahko v tujino po­toval prosto, se udeleževal številnih konferenc, predaval po univerzah in imel neomejene stike z drugimi znanstveniki po svetu. To je obdobje, ko je Stalin že prevzel oblast trdno v svoje roke in ko se že kažejo obr isi br utalnega totalitar nega režima pred drugo svetovno vojno. Pregled del, ki jih je Vernadski pošiljal Niki­tinu v Ljubljano, pokaže, da je izbor bolj ali manj nakljucen. Predstavlja izbor clankov, ki so zna­cilni za delovanje Vernadskega v obdobju od leta 1920 do 1930. V tem casu nastane njegovo zna­menito delo Biosfera (ruska izdaja 1926), ki ga spremljajo tudi številni drugi clanki s podobno tematiko. Ti clanki v naboru del, posredovanem v Ljubljano mocno prevladujejo. Poleg tega so bili v Ljubljano poslani tudi clanki, ki so se tako ali drugace ukvarjali z radioaktivnimi minerali in naravno radioaktivnostjo. Na tem podrocju je bil Vernadski neverjeten vizionar, saj je že leta 1922 ustanovil Radijev inštitut, ki je imel nalogo raziskovati pojavljanje naravnih radioaktivnih mineralov. V casu dopisovanja je bil Vernadski ustvarjalen tudi na podrocju zgodovine znanosti in filozofije znanosti. Nobenega od teh del Ver­nadski ni poslal v Ljubljano. Nikitinov arhiv je skoraj v celoti izgubljen. Ohranjenih je le nekaj arhivskih drobcev v Zgo­dovinskem arhivu Univerze v Ljubljani. Vsa dosedanja preverjanja arhivskega gradiva o Ni­kitinu v Ruski federaciji niso obrodila nobenih sadov. Izjema je le predstavljena koresponden­ca. Nasprotje pa predstavlja ohranjeno arhivsko gradivo Vernadskega. Njegova zbrana dela ob­segajo kar 24 knjig, veliko je tudi zbirk njegove korespondence, njen velik del pa ni niti obdelan. Velika verjetnost je, da se nam bo v tem gradi­vu v prihodnosti razkrila še kakšna zanimiva in pomembna informacija o sodelovanju med Niki­tinom in Vernadskim. Sklep V clanku smo predstavili prevod in komentar šestih dopisov, ki jih je profesor mineralogije in petrologije na Univerzi v Ljubljani Vasilij Vasi­lijevic Nikitin (1867-1945) poslal znamenitemu ruskemu geologu, geokemiku in filozofu Vladi­mirju Ivanovicu Vernadskemu (1863-1945). Do sedaj nam ta korespondenca ni bila znana. Iz korespondence je razvidno, da sta se oba znan­stvenika osebno poznala, in da sta si izmenjeva­la svoja dela. Korespondenca je po številu enot in po vsebini skromna. Ne glede na to, da je imel Vernadski v Rusiji privilegiran položaj in da je v primerjavi z drugimi imel relativno veliko inte­lektualno svobodo, lahko to pripišemo dejstvu, da je bil Nikitin politicni emigrant, ki je po svoji poroki spadal v razred nižjega ruskega plemstva in veleposestništva. Bil je tudi neproletarskega izvora, kar je bil še dodaten vzrok, da je zapustil Rusijo. Verjetno sta bila zaradi tega dopisovalca v svojih pismih zelo previdna. Predstavljena korespondenca nam odkriva pomemben drobec iz delovanja in poucevanja geologije pred drugo svetovno vojno na Univerzi v Ljubljani. Ceprav je šlo za mlado in relativno majhno univerzo, nam stiki med Nikitinom in Vernadskim dokazujejo, da so se takratni ucitelji trudili vzpostaviti stike s svetom in tedanjim ra­zvojem geološke znanosti. Zahvala Velika zahvala gre prof. dr. Sergeyu A. Sokratovu s Fakultete za geografijo Moskovske državne univerze – MGU, ki je vztrajno podpiral avtorjevo dolgoletno zanimanje za delo Vladimirja Ivanovica Vernadskega. Po nakljucnem odkritju obstoja Nikitinovih pisem je prof. Sokratov organiziral njihovo iskanje, kopiranje in prepis. Brez njegove pomoci clanka ne bi bilo. Do pisem ne bi prišli brez angažirane pomoci Irine N. Sokratove z Oddelka za znanosti o Zemlji Predsedstva Ruske akademije znanosti, ki je poiskala ljudi z dos­topom do arhiva Vernadskega. Prepis pisem je opra­vila sodelavka Oddelka za geokemijo pokrajine in geografijo tal Fakultete za geografijo Moskovske dr­žavne univerze – MGU Tatiana M. Dianova, brez nje­ne pomoci prevodi in kriticni pretres pisem ne bi bili mogoci. Za posredovanje pisem in dovoljenje za objavo prevodov se avtor zahvaljuje Arhivu Ruske akademije znanosti v Moskvi, Ruska federacija. Clanek je nastal v okviru dejavnosti Razisko­valnega programa št. P-0020 »Podzemne vode in geokemija«, ki ga sofinancira Javna agencija za razi­skovalno dejavnost Republike Slovenije iz državnega proracuna. Viri in literatura Duhovnik, J. 1953: Vasilij Vasiljevic Nikitin – in memoriam. Geologija, 1: 5-10. Kidric, F. 1939: Zoisova korespondenca. Zvezek 1, 1808-1809. Akademija znanosti in umetnosti, 225 p. Kidric, F. 1941: Zoisova korespondenca. Zvezek 2, 1809-1810. Akademija znanosti in umetnosti, 196 p. Soban, D. 2004: Joannes A. Scopoli – Carl Linnaeus dopisovanje/correspondence 1760­1775. Prirodoslovno društvo Slovenije, 346 p. .. .. ....., .. .. ........., .. .. ......., .. .. ......, 1992: ......... . ............... ...... -........ ........ ............ ....., dostopno na http://ver nadsky.name/ alfavitny-j-ukazatel-trudov/ (zad nji dostop 24. 09. 2018) GEOLOGIJA 61/2, 239-252, Ljubljana 2018 © Author(s) 2018. CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.017 Sistematicen pregled geoloških ucnih ciljev in ucbeniških vsebin v osnovnih šolah in v splošnih gimnazijah Systematic overview of geological learning objectives and textbook contents for primary schools and gymnasiums Rok BRAJKOVIC1, Mojca BEDJANIC2, Neža MALENŠEK ANDOLŠEK1, Nina RMAN1 , Matevž NOVAK1, Kaja ŠUŠMELJ3 & Petra ŽVAB ROŽIC3 1Geološki zavod Slovenije, Dimiceva ulica 14, SI-1000 Ljubljana, Slovenija; 2 Zavod RS za varstvo narave - OE Maribor, Pobreška cesta 20a, SI-2000 Maribor, Slovenija; 3 Oddelek za geologijo, Naravoslovnotehniška fakulteta UL, Aškerceva 12, SI-1000 Ljubljana, Slovenija; e-mail: rok.brajkovic@geo-zs.si Prejeto / Received 15. 10. 2018; Sprejeto / Accepted 23. 11. 2018; Objavljeno na spletu / Published online 20. 12. 2018 Kljucne besede: izobraževanje, geologija, kurikulum, ucbeniki, osnove šole, gimnazije, matura Key words: education, geology, curriculum, textbooks, primary school, gymnasiums, matura examination Izvlecek Poucevanje geoloških vsebin v osnovni šoli in na splošnih gimnazijah do sedaj še ni bilo sistematicno obravnavano. V okviru Skupine za popularizacijo geologije, ki deluje pod okriljem Slovenskega geološkega društva, smo si zastavili cilj, pridobiti vpogled v poucevanje geoloških vsebin v osnovnih šolah in na splošnih gimnazijah. Pri pregledu smo zajeli tudi splošno maturo, saj le-ta predstavlja zakljucek srednješolskega izobraževanja. Da bi zagotovili pregled nad poucevanjem geoloških vsebin, smo najprej pregledali predmetne ucne nacrte ter izpitne kataloge za maturitetne predmete. Pregledali smo tudi veljavne ucbenike in maturitetne izpitne pole pri predmetih, kjer se geološke vsebine pojavljajo. Dobljene geološke vsebine smo razvrstili v šest splošnih geoloških vsebinskih sklopov. Vse vsebine so bile vrednotene po Bloomovi taksonomiji, ki na podlagi strukturiranosti omogoca prepoznavanje taksonomske zahtevnosti ucnih ciljev in preverjanj znanj. Vrednotili smo tudi medpredmetno povezanost. Ugotovili smo, da se geološke vsebine v osnovni šoli obravnavajo pri obveznih predmetih Družba, Naravoslovje in tehnika, Naravoslovje, Geog rafija in Biologija ter izbir nem predmetu Okoljska vzgoja, v splošnih gimnazijah pa pri predmetih Geografija in Biologija, kjer se znanje preverja tudi na maturi. Ucni cilji in vsebine se vecinoma smiselno nadgrajujejo, vendar pa besedila v ucbenikih pogosto nezadostno in strokovno pomanjkljivo predstavijo posamezno tematiko. Kar nekaj za družbo pomembnih geoloških tematik je v formalnem izobraževanju izpušcenih. Pri posameznih medpredmetno povezanih sklopih smo podali priporocila za promotorje znanosti, kako prispevati k boljšemu in strokovno pravilnemu razumevanju vsebine sklopa. Predstavitev geologije v ucbenikih je nezvezna, strokovno pomanjkljiva in vsebinsko zelo okrnjena. Pricujoca raziskava nam daje izhodišce za zacetek umešcanja posodobljenih in združeno predstavljenih geoloških vsebin v formalno izobraževanje. Abstract Teaching of geological contents in elementary school and gymnasiums has not yet been systematically addressed. Under the auspices of Slovenian Geological Society, members of the Task Group for the Popularization of Geology, have set themselves the goal of gaining insight into the teaching of geological contents in elementary schools and gymnasiums. Review also covered general matura examination as it represents the completion of secondary education. In order to provide an overview of the teaching of geological contents, we first reviewed the subject curricula and the knowledge catalog for general matura subjects. We also reviewed valid textbooks and general matura exam questions. The extracted geological contents were classified into six general geological content assemblages. All extracted geological content was evaluated according to Bloom's taxonomy, which, on the basis of structure, enables the recognition of the taxonomic complexity of learning objectives and knowledge tests. We also evaluated cross-curricular relationships. We have discovered that geological contents are taught in elementary school in obligatory subjects such as Society, Natural sciences and engineering, Natural sciences, Geography, Biology and in optional subject Environmental education. In gymnasiums geological contents are taught in the subjects Geography and Biology, where knowledge is also checked at general matura. Learning objectives and contents are mostly appropriately upgraded, but the content presented in textbooks is often R. BRAJKOVIC, M. BEDJANIC, N. MALENŠEK ANDOLŠEK, N. RMAN, M. NOVAK, K. ŠUŠMELJ & P. ŽVAB ROŽIC insufficient and professionally inadequate. There is also a lack of the important geological topics in the field of formal education. For individual cross-curricular sections, we have made recommendations for promoters of science to contribute to a better understanding and the correct and professional content presentation in public. The presentation of geology in the textbooks is discrete, often professionally flawed, and the content is very limited. This research provies a starting point for starting the placement of updated and appropriate geological contents into formal education. Uvod Poucevanje geoloških vsebin v formalnem iz­obraževanju je kljucno, saj lahko le tako zagoto­vimo, da posameznik razume vlogo geologije pri soustvarjanju uspešne sodobne družbe. Ceprav so geološke teme zelo privlacne in prisotne v jav­nosti, le-te še zdalec ne dosegajo prepoznavnosti drugih naravoslovnih tematik. Eden izmed ra­zlogov za takšno situacijo je nejasna predstavitev geologije kot vede v osnovnih in srednjih šolah. Med letoma 1982 in 1990 je obstajal samostojen 4-letni srednješolski program za geološkega teh­nika. Danes se geologija v šolah poucuje razdro­bljeno, geološke vsebine se pojavljajo pri družbo­slovnih in naravoslovnih predmetih, najvec pri predmetu Geografija. Geološke vsebine se v slovenskem šolskem sistemu pojavijo že v vrtcih, kjer so navezane na geologijo posredno, skozi spoznavanje ma­terialov in pokrajine. Prvi ucni cilji, neposred­no vezani na geološke tematike, so definirani na razredni stopnji osnovne šole, v 4. razredu pri predmetih Družba ter Naravoslovje in tehnika (Zvonar et al., 2017). Majcen (2003) je prvi podal pregled poucevanja geoloških vsebin. Omejil se je na osnovno šolo, kjer ugotavlja, da so vsebine med predmeti prevec razdrobljene in ucencu ne omogocajo jasnega pregleda nad geološkimi te­matikami, geologije kot vede pa ne predstavijo zadovoljivo. Da je poucevanje geoloških vsebin v formalnem izobraževanju na nacin, ki bi ucen­cem omogocil povezovanje naravnih pojavov in življenja na Zemlji v razu m ljive in zak ljucene ce­lote, izjemnega pomena za razumevanje procesov na Zemlji, njene zgodovine v navezavi na seda­njost, in zavedanja o pomembnosti mineralnih surovin v našem vsakdanjem življenju, opozarja tudi Novak (2013). Poleg tega je raba geoloških terminov v ucni literaturi pogosto neusklajena in neprimerna (Popit, 2005). Raziskava nacionalnih ucnih nacrtov v naravoslovju, ki je bila opravlje­na v okviru projekta ESTEAM kaže, da je geo­loškim tematikam v osnovnošolskem izobraževa­nju skupno namenjenih le 30 ur (Catana & Vilas Boas, 2017). Pri tem se moramo seveda zavedati, da so tako ure kot vsebine porazdeljene med vec predmetov. Ali je takšen nacin poucevanja pri­ meren, pa bi lahko ocenili s študijo trajnosti zna­nja. Trajnost znanja je odvisna od veliko dejav­ nikov. Zelo je povezana s tem, ali je bilo ucenje snovi aktivno navezano na predznanje, ali je po­ sameznik ucenje tematike dojemal kot smiselno, ali je bilo povezano s problemi iz prakse ter ali je bilo navezano na dosedanje izkušnje. Trajnost znanja se poveca tudi s smiselnim medpredmet­nim povezovanjem (Marentic Požarnik, 2001a). Glavni raziskovalni cilj Skupine za populari­zacijo geologije, ki deluje pod okriljem Slovenske­ga geološkega društva, je bil sistematicen vpog­led v poucevanje geoloških vsebin v osnovnih šolah in na splošnih gimnazijah. Pregledali smo ucne nacrte ter analizirali vsebine ucbenikov za osnovne šole in splošne gimnazije. Ucne nacrte in vsebine smo vrednotili po Bloomovi taksono­miji (Kennedy, 2015), z namenom analize stopnje zahtevnosti. Ker matura predstavlja zakljucek srednješolskega izobraževanja, smo pregledali, v kakšnem obsegu in na kakšni stopnji zahtevnosti se preverjajo geološke vsebine na splošni maturi. Želeli smo ugotoviti pricakovano stopnjo predznanja po koncanem srednješolskem iz­obraževanju. Zato smo z namenom pridobitve vpogleda v nadgrajevanje ucnih ciljev in vsebin v ucbenikih po posameznih tematskih sklopih pregledali, ali se vsebine smiselno nadgrajujejo in ali je medpredmetna povezanost poucevanja za­dostna, da lahko ucenec oz. dijak pridobi celostni pregled nad poucevano tematiko. Metode dela Ucni nacrt je šolski dokument, ki za posame­zen predmet predpisuje obseg in stopnjo znanja ter zaporedje ucne snovi. Njegova temeljna vloga je, da zagotavlja sistematicno poucevanje ter cilj­no usmerja ucenje v vsebinsko povezane sklope. Znotraj ucnih nacrtov so ucni cilji razdeljeni na splošna znanja in posebna znanja. Splošna zna­nja so opredeljena kot znanja potrebna za sploš­no izobrazbo, in so namenjena vsem ucencem in dijakom, zato jih mora ucitelj obvezno obravna­vati. Posebna znanja opredeljujejo dodatna ali poglobljena znanja, ki jih ucitelj obravnava gle­de na zmožnosti in interese dijakov (MIZŠ – ucni nacrti, 2018). Vloga ucbenikov se skozi napredek v tehnikah poucevanja spreminja, a ucbenik še vedno ostaja ena od prvih knjig, s katero se v for­ malnem izobraževanju sreca posameznik. Zato ucbenik za ucenca predstavlja osnovno sredstvo v procesu ucenja, s pomocjo katerega na aktiven nacin pristopi k ucenju snovi. Pregled ucnih na­crtov in ucbenikov ima velik pomen, saj s tem lahko ugotovimo pricakovano stopnjo predzna­nja ter postopnost in smiselnost nadgrajevanja razdrobljenih geoloških vsebin. Ucni nacrti in ucbeniki V okviru raziskave smo pregledali in ana­lizirali 18 predmetnih ucnih nacrtov in 73 ucbenikov za osnovne šole ter 14 ucnih nacrtov in 26 ucbenikov za splošne gimnazije (Tabela 1). Vse v šolskem letu 2017/2018 veljavne ucbenike za predmete, pri katerih smo ugotovili pojavlja­nje geoloških ciljev in vsebin (Tr ubar – ucbeniški sklad, 2018), smo analizirali z namenom pridobi­tve vpogleda v obseg vsebin, definiranih z ucni­mi cilji, zapisanimi v predmetnih ucnih nacrtih (MIZŠ – ucni nacrti, 2018). Posamezne cilje smo vrednotili, jih povezali z vsebinami v ucbenikih in preucili njihovo ujemanje. Preko tega smo vre­dnotili tudi medpredmetno povezanost. Matura Analizirali smo izpitna kataloga za predmeta Biologija in Geografija, pri katerih se na maturi preverja znanje geoloških tematik. Pregledanih je bilo tudi 60 maturitetnih pol med letoma 2008 in 2017, za katere veljata trenutna ucna nacrta za predmeta Geografija in Biologija. Vprašanja in pricakovane odgovore smo glede na strokovno ustreznost vrednotili z: I. – ustreza, II. – delno ustreza in III. – ne ustreza. Geološke tematike Vse izdvojene ucne cilje v ucnih nacrtih, ucne vsebine z geološkimi tematikami, cilje iz izpitne­ga kataloga za maturo ter maturitetna vprašanja in odgovore smo na podlagi strokovne presoje razvrstili v šest osnovnih geoloških tematik. S tem smo ustvarili smiselno povezan sklop ciljev in snovi, znotraj katerega smo nato iskali med­predmetno povezovanje in nadgradnjo ciljev. Razvršcene osnovne geološke tematike so: -Osnove geologije, ki zajemajo vsebine, pov­ezane z zgradbo Zemlje, oblikovanostjo površja, s procesi, ki se odvijajo na Zemlji, in vse vsebine regionalne geologije. -Paleontologija, ki zajema vsebine pov­ezane s fosili, izvorom življenja na Zemlji in evolucijo. -Petrologija in mineralogija, ki zajemata vsebine o mineralih in kamninah ter nji­hovem prepoznavanju, vsebine o uporabi mineralnih surovin, posredno pa smo v to tematiko uvrstili tudi del pedoloških vse­bin, ki se nanašajo na maticno podlago in nastanek tal. -Hidrogeologija, kamor smo razvrstili cil­je povezane s podzemno vodo, njenim onesnaževanjem in izkorišcanjem, kot tudi splošne tematike povezane z vodonosniki in pitno vodo. -Kras smo locili zaradi njegove specifike in pomembnosti v slovenskem prostoru. V to temo so uvršcene vsebine povezane z nas­tankom površinskih in podpovršinskih kraških oblik ter z geološkim razvojem kraških pokrajin. -Ekologija in varstvo okolja zajemata temati­ki o vlogi geologije pri ohranjanju naravnih Tabela 1. Število pregledanih ucbenikov za posamezen predmet v osnovni šoli in v splošni gimnaziji. Table 1. Number of textbooks examined for each subject in Primary school and at Gymnasium. Predmet Subject Št. ucbenikov v osnovni šoli Num. of textbooks in primary school Št. ucbenikov v splošni gimnaziji Num. of texbooks in general Gymnasiums Družba Society 20 / Naravoslovje in tehnika Natural sciences and engineering 16 / Naravoslovje Natural sciences 13 / Geografija Geography 21 14 Biologija Biology 3 12 R. BRAJKOVIC, M. BEDJANIC, N. MALENŠEK ANDOLŠEK, N. RMAN, M. NOVAK, K. ŠUŠMELJ & P. ŽVAB ROŽIC virov in vrednotenju posledic prekomerne­ ga izkorišcanja le-teh ter pri vplivih na okolje in vsebine povezane z varstvom ge­ ološke dedišcine. Vrednotenje Vse izdvojene cilje in vsebine z geološko te­ matiko v ucnih nacrtih v osnovnih šolah in na splošnih gimnazijah ter maturitetni izpitni kata­log in izpitna vprašanja na maturi z geološko te­ matiko, smo vrednotili po Bloomovi taksonomiji (Kennedy, 2015). Ta razvršca kompleksnost mi­selnih procesov v hierarhijo, od najnižje stopnje poznavanja, ki od posameznika zahteva le prik­lic posameznih dejstev, do najvišje stopnje vred­ notenja, kjer se pricakuje, da je ucenec sposoben presojanja o vrednosti ter pomembnosti dolocne tematike. Da bi ucenec lahko dosegal višje ta­ksonomske cilje, mora biti najprej vzpostavljeno osnovno predznanje na nižjih stopnjah. Bloomo­va taksonomija se uporablja za pisanje ucnih ci­ljev in izidov, pripravo strukturiranih preverjanj znanja in pripravo evalvacijskih gradiv. Z vnap­rej pripravljeno strukturo in seznamom glagolov nam omogoca, da cilje sistematsko zastavimo po taksonomskih stopnjah. Strukturiranost glago­lov pri pisanju ciljev nam omogoca tudi njiho­vo prepoznavanje (sl. 1). Primerjali smo stopnje vrednotenja med ucnimi cilji v ucnih nacrtih in maturitetnem izpitnem katalogu ter ucnimi vsebinami v ucbenikih in izpitnimi vprašanji na maturi, ter analizirali, ali ucbeniške vsebine ustrezajo zahtevnosti ucnih ciljev. Rezultati in diskusija Geološke vsebine in njihova zahtevnost po posameznih predmetih v osnovni šoli Po pregledu ucnih nacrtov smo ugotovili, da se geološke vsebine v osnovni šoli poucujejo pri ob­veznih predmetih Družba, Naravoslovje in teh­nika, Naravoslovje, Geografija in Biologija (Ta­bela 2). Skupaj je vseh geoloških ciljev v osnovni šoli 62, njihova povprecna zahtevnost pa je na taksonomski stopnji razumevanja. Najvec geolo­ških ciljev in vsebin je pri predmetu Naravoslov­je v 6. razredu (9) ter pri predmetu Geografija v 6. razredu (11). Zahtevnost ciljev je za vsako od tematik prikazana na sliki 2. Geološke vsebine se poucujejo tudi pri predmetu Okoljska vzgoja, a v statisticni pregled in medpredmetno nadgrajeva­nje niso bile zajete, saj zaradi nedostopnosti po­ datkov o izvajanju ter številu vkljucenih ucencev ne ustrezajo ciljem raziskave. Pri predmetu Družba (Budnar et al., 2011), ki se izvaja v 4. in 5. razredu, so v okviru geoloških vsebin zastopane tematike osnov geologije ter ekologije in varstva okolja. Vseh geoloških ciljev je 7. Vsebine iz ekologije in varstva okolja vsebu­jejo višje taksonomske cilje na stopnji uporabe, medtem ko so cilji, vezani na vsebine osnov geo­logije, povprecno na stopnji poznavanja in razu­mevanja. Pov precna zahtev nost ucnih ciljev je na taksonomski stopnji med poznavanjem in razu­mevanjem. Ucenci pri predmetu Dr u žba spoznajo naravne enote Slovenije, podrobneje pa spozna­jo domaco pokrajino. Tukaj se od geoloških tem obravnavajo kamnine, relief, vode in tla. Srecajo Sl. 1. Hierarhicna ureditev kompleksnosti miselnih procesov po Bloomu (prirejeno po Kennedy, 2015). Fig. 1. A hierarchical arrangement of the complexity of thought processes after Bloom (modified after Kennedy, 2015). Tabela 2. Geološki ucni cilji, razvršceni po tematskih sklopih, pri posameznem predmetu v osnovni šoli. Table 2. Geological learning objectives classified by topics, for individual subjects in Primary school. Predmet/Tema Subject/Topic Osnove geologije Geology Basics Paleontologija Paleontology Petrologija/ Mineralogija Petrology/ Mi­neralogy Hidrogeologija Hydrogeology Kras Karst Ekologija/ Var­stvo okolja Ecology / En­vironmental protection Družba 4. in 5. r Society 4. and 5. cl. 6 0 0 0 0 1 Naravoslovje in tehnika 4. in 5. r Natural sciences and engine­ering 4. and 5. cl. 0 1 0 4 0 0 Naravoslovje 6. in 7. r Natural sciences 6. and 7. cl. 6 0 3 2 0 4 Geografija 6., 7., 8. in 9. r Geography 6., 7., 8., and 9. cl. 11 0 1 0 0 13 Biologija 8. in 9. r Biology 8. and 9. cl. 2 5 1 0 0 2 14 12 10 8 6 4 2 0 Osnove geologije/Geology Paleontologija/Paleontology Petrologija/Mineralogija; Hidrogeologija/Hydrogeology Kras/Karst Ekologija/Varstvo okolja; basic Petrology/Mineralogy Ecology/Environmental protection Poznavanje/Knowledge Razumevanje/Comprehension Uporaba/Application Analiza/Analysis Sinteza/Synthesis Vrednotenje/Evaluation Sl. 2. Število geoloških ucnih ciljev v osnovni šoli, razvršcenih po tematskih sklopih, predstavljenih po stopnji zahtevnosti. Fig. 2. Number of geological learning objectives in Primary school, classified according to topics, presented by level of difficulty. se z razlago procesov, ki vplivajo na oblikovanost površja. Posredno se omenijo tudi kraške oblike. Spoznajo obmocja rudarjenja v Sloveniji. Znot­raj vsebin varovanja okolja se obravnavajo po­sledice rudarjenja, varovanje geoloških naravnih vrednot ter nujnost recikliranja za zmanjšanje vpliva na okolje. Geološke tematike so v okviru predmeta Družba predstavljene razdrobljeno in ne tvorijo celote, ki bi predstavila geologijo kot vedo. Predmet Naravoslovje in tehnika se poucuje v 4. in 5. razredu osnovne šole (Vodopivec et al., 2011). Predmet obravnava vsebine paleontologije in hidrogeologije. Vseh geoloških ucnih ciljev je 5. Zahtevnost ucnih ciljev iz vsebin paleontolo­gije je na taksonomski stopnji uporabe, ucni cilji iz hidrogeologije pa na stopnji razumevanja. Pov­ precna zahtevnost vseh ciljev je na taksonomski stopnji razumevanja. Paleontološke vsebine za­ jemajo izvor življenja na Zemlji in primere živih R. BRAJKOVIC, M. BEDJANIC, N. MALENŠEK ANDOLŠEK, N. RMAN, M. NOVAK, K. ŠUŠMELJ & P. ŽVAB ROŽIC bitij v preteklosti. Na kratko je razložen tudi po­stopek fosilizacije. Hidrogeologija zajema vsebine izvora vode na Zemlji, vodnega kroga in preta­ kanja vod. Razloženo je, koliko vode imamo na Zemlji ter kakšno. Predstavljene so lastnosti vode in od kje pride voda v tla, razloženo pa je tudi, kaj je vodonosnik. Opisana sta pojma prepustnost in gladina podzemne vode. Pojasnjeno je, kako vodo crpamo na površino ter kaj so vodnjaki. Opisano je še, kako se voda pretaka po površini ter pod njo. Predstavljen je problem onesnaženosti voda. Geo­loške tematike so pri tem predmetu bolj strnjene, geologija pa kljub temu ni predstavljena kot veda. Pri predmetu Naravoslovje v 6. in 7. razredu (Skvarc et al., 2011) je obseg geoloških vsebin re­lativno širok. Obravnavane so vsebine osnov ge­ologije, petrologije in mineralogije, hidrogeologi­je ter ekologije in varovanja okolja. Vseh ucnih ciljev z geološko tematiko je 15. Najvec ciljev je iz vsebin osnov geologije, ki so na taksonomski stopnji poznavanja, enako kot vsebine petrolo­gije in mineralogije. Povprecna zahtevnost vseh ciljev je na taksonomskih stopnjah poznavanja in razumevanja. Ucenci spoznajo sestavo Zemlje na osnovnem prerezu. Ucijo se o mineralih kot gradnikih kamnin, razložena je Mohsova trdotna lestvica. Kamnine razclenijo glede na nastanek, spoznajo njihove lastnosti ter možnosti uporabe. V okviru kamninskega kroga so razloženi proce­si in nastanek kamnin. Preko kamnin je razložen tudi nastanek tal v povezavi z maticno podlago. Hidrogeološke vsebine zajemajo razlikovanje vi­rov voda v naravi. Predstavljena je kemijska se­stava vode na primerih mehke in trde vode ter pretakanje voda v kraškem svetu. Vsebine zaje­majo tudi onesnaževanje podzemne vode. Vsebine varovanja okolja zajemajo fosilna goriva ter nji­hov vpliv na okolje, pa tudi prekomerno izkori­šcanje naravnih virov. Geološke vsebine so jasno predstavljene, pogosto pa se pri kompleksnejših razlagah v ucbeniških tekstih pojavljajo strokov­ne netocnosti. Kljub vecjemu obsegu geoloških vsebin geologija kot veda ni omenjena. Predmet Geografija (Kolnik et al., 2011), ki se v osnovni šoli poucuje od 6. do 9. razreda, za­jame najvec geoloških vsebin. Te so v 8. razredu izvzete iz ucnega nacrta in se v ucbenikih pojav­ljajo samo kot zanimivosti. Vsebine so zgošcene v tematskih sklopih osnove geologije ter ekologi­ja in varovanje okolja, delno pa tudi petrologija in mineralogija. Vseh ucnih ciljev, povezanih z geološkimi tematikami, je 25. Taksonomsko naj­zahtevnejše so vsebine ekologije in varstva oko­lja, ki so na stopnji uporabe. Druge obravnavane vsebine so na taksonomski stopnji razumevanja. Povprecna zahtevnost ciljev pri predmetu je med razumevanjem in uporabo. Ucenci spoznavajo notranjo zgradbo Zemlje na osnovnem geološkem prerezu. Obravnavana je tematika potresov z razlago premikanja tektonskih plošc. Razložen je pojem epicenter. Na tektoniko plošc je nave­zan tudi nastanek vulkanov, ki pa je obravna­van zgolj na posameznih primerih. Obravnava se tudi paleogeografska in geotektonska razcle­nitev Slovenije. Razložena sta osnovna razcle­nitev kamnin in nastanek krasa. Kot posledica podnebnih sprememb je navedeno spreminjanje okolij, ucenci se ucijo pomena ohranjanja oko­lja za trajnostni razvoj družbe ter razumevanja vpliva clovekovih posegov v naravo. Vsebine so med razredi zelo razdrobljene in ne predstavljajo zakljucene celote, iz katere bi ucenec lahko pre­poznal geologijo kot vedo. Predmet Biologija (Vilhar et al., 2011) se po­ucuje v 8. in 9. razredu. Zajema vsebine osnov geologije, paleontologije, petrologije in minera­logije ter ekologije in varstva okolja. Vseh ucnih ciljev, povezanih z geološkimi vsebinami, je 10. Najvišje taksonomske stopnje dosegajo vsebine ekologije in varstva okolja, in sicer so na stopnji od razumevanja do uporabe. Najnižjo stopnjo zajamejo cilji osnov geologije, ki so na stopnji poznavanja. Vsebine obsegajo teorijo tektonike plošc, ki je predstavljena skozi vpliv na razšir­jenost vrst. Predstavljeni so geološke dobe, na­stanek planeta Zemlja in spreminjanje atmosfere z vplivom na izvor in razvoj življenja. Tematika evolucije je obravnavana zelo skopo oziroma po­sredno. Predstavljana je na nekaj dejstvih, pred­vsem na predstavitvi petih velikih izumiranj v geološki zgodovini. Predstavljeni so fosilizacija ter posamezni tipi fosilov. Vsebine ekologije in varstva okolja so predstavljene skozi clovekov vpliv na okolje. Poudarek je na kroženju snovi v naravi med posameznimi ekosistemi in okolji. Obravnavajo se tudi kopicenje strupenih snovi v organizmih ter nastanek kislega dežja, tople g re-de in posledice uporabe fosilnih goriv. Vsebine so strokovno ustrezne, vendar niso celostno pred­stavljene, zato predvsem pri tematiki o evoluciji ne ponujajo zadostnega razumevanja. Predmet Okoljska vzgoja se poucuje v 7., 8. in 9. razredu. Obravnavane vsebine zajemajo obnovlji­ve in fosilne energetske vire, kjer ucenci spozna­jo pomen in nacine varcevanja in gospodarnega ravnanja z naravnimi viri. Vsebine o mineralnih surovinah so navezane na prepletenost ekoloških ter ekonomsko-dr užbenih vidikov izkorišcanja, ter razumevanju nastanka in reševanja okoljskih problemov. Zaskrbljujoce je dejstvo, da niti v enem osnov­nošolskem ucbeniku ni podane defi nicije geologi­je kot vede. Geološke vsebine in njihova zahtevnost po posameznih predmetih v splošnih gimnazijah S pregledom ucnih nacrtov smo ugotovili, da se geološke vsebine na splošnih gimnazijah pou­cujejo pri predmetih Biologija in Geografija (Ta­bela 3), kjer se znanje preverja tudi na maturi. Na splošnih gimnazijah je najvec geoloških ciljev pri predmetu Geografija (1., 2., 3. in 4. letnik), in sicer 67. Njihova povprecna zahtevnost je na ta­ksonomski stopnji uporabe. Pri Biologiji (1., 2., 3. in 4. letnik) je geoloških ciljev 12, zahtevnost pa na stopnji razumevanja. Najvec tematik je razvr­šcenih v sklopu osnov geologije, ki je po takso­nomski zahtevnosti med vsemi najmanj zahteven. Taksonomsko najbolj zahteven sklop so vsebine ekologije in varstva narave. Te dosežejo povprec­ no zahtevnost do stopnje uporaba. V primerjavi z osnovno šolo se povprecna zahtevnost ciljev na gimnaziji pri vseh sklopih poviša za eno takso­nomsko stopnjo. Zahtevnost ciljev je predstavlje­na pri vsaki tematiki posebej in je prikazana tudi na spodnji sliki (sl. 3). Pri predmetu Biologija (Vilhar et al., 2008), ki se poucuje od 1. do 3. letnika ter izbirno v 4. le­tniku, je poudarek na vsebinah paleontologije ter ekologije in varstva narave. Obravnavajo se tudi vsebine osnov geologije ter hidrogeologije. Pale­ontološke vsebine zajemajo izvor in razvoj življe­nja. Podana je definicija fosila in nacini fosiliza­cije. Pri evoluciji so opisana množicna izumrtja v geološki zgodovini, razvoj življenja pa je podan razdrobljeno, a kljub temu dokaj podrobno. Sis­tematicno je opisana evolucija cloveka. Vsebine ekologije in varstva okolja so zajete s kroženjem snovi in elementov med ekosistemi. Podrobno so razloženi nastanek in vpliv kislega dežja, tople Tabela 3. Geološki ucni cilji, razvršcenih po tematskih sklopih, pri posameznem predmetu v splošnih gimnazijah. Table 3. Geological learning objectives classified by topics, for individual subjects in Gymnasiums. Predmet/Tema Subject/Topic Osnove geo­logije Geology Basics Paleontologija Paleontology Petrologija/ Mineralogija Petrology/ Mine­ralogy Hidrogeologija Hydrogeology Kras Karst Ekologija/ Var­stvo okolja Ecology/ En­vironmental protection Biologija Biology 1 3 0 3 0 5 Geografija Geo­graphy 48 0 7 4 6 2 0 5 10 15 20 25 Osnove geologije/Geology basic Paleontologija/Paleontology Petrologija/Mineralogija; Petrology/Mineralogy Hidrogeologija/Hydrogeology Kras/Karst Poznavanje/Knowledge Razumevanje/Comprehension Uporaba/Application Analiza/Analysis Sinteza/Synthesis Vrednotenje/Evaluation Ekologija/Varstvo okolja; Ecology/Environmental protection Sl. 3. Število ucnih ciljev, razvršcenih po tematskih sklopih, predstavljenih po stopnji zahtevnosti v splošnih gimnazijah. Fig. 3. Number of geological learning objectives in Gymnasiums, classified according to topics, presented by level of difficulty. R. BRAJKOVIC, M. BEDJANIC, N. MALENŠEK ANDOLŠEK, N. RMAN, M. NOVAK, K. ŠUŠMELJ & P. ŽVAB ROŽIC grede in toplogrednih plinov ter ozona, in one­snaženje zraka. Natancno so predstavljene vsebi­ne o škodljivosti in izvoru radona, o problema­tiki radioaktivnih odpadkov ter koncentriranja toksicnih kovin v tleh in v organizmih. Predsta­vljena je remediacija tal na onesnaženih podroc­jih. Obravnavana sta onesnaževanje okolja ter vpliv cloveka na ekosisteme v navezavi na fosilna goriva. Vsebine so predstavljene strokovno tocno in v vecini primerov zelo podrobno. Pri predmetu Geografija (Polšak et al., 2008), ki se poucuje od 1. do 3. letnika ter izbirno v 4. letniku, je obseg geoloških vsebin najvecji. Pred­stavljeni so vsi tematski sklopi z izjemo paleonto­logije. Osnove geologije zajemajo zelo širok nabor geoloških vsebin. Predstavljeni so zunanji in not­ranji procesi, ki vplivajo na oblikovanost površja. Paleogeografski razvoj sveta je podan na nekaj primerih. Na tektoniko plošc so navezane vsebi­ne o potresih in vulkanih. Obsežneje so predsta­vljeni tipi površja in njihove glavne znacilnosti z navezavo na njihov nastanek. V okviru geogra­fije Evrope so predstavljene posamezne geološke znacilnosti regij oz. držav ter njihov nastanek. Tako je omenjen nastanek Alp, Baltskega šci­ta, stare orogenetske faze, geološke znacilnosti Islandije in celinska poledenitev Severne Evro­pe. Pr i obravnavanju geog ra fije sveta se, podobno kot pri Evropi, vsebine ucbenikov osredotocajo na predstavitev posameznih geoloških znacil­nosti regij. Dijaki spoznajo cone subdukcije, glavne orogenetske faze dviga gorovij v Ameriki, Himalaji in Andov ter tamkajšnji vulkanizem. Predstavljeni so nastanek avstralskega kontinen­ta ter glavne geološke enote Afrike. Pogosto so kot zanimivosti podana tudi razlicna rudna bo­gastva držav, arteški vodonosniki, nastanek ato­lov ter glavni energetski viri. Pri obravnavanju znacilnosti Slovenije je predstavljena njena ge­ološka zgodovina. Razložen je nastanek površja Slovenije skozi Zemljino zgodovino, podana je tudi razclenitev na geotektonske enote. Opisani so primeri hujših geoloških naravnih nesrec. Pri izbirnih vsebinah v 4. letniku so podane poseb­ nosti geološke sestave in njihov vpliv na obliko­vanost površja po posameznih pokrajinah Slove­nije. Petrološke tematike zajemajo opis nastanka razlicnih tipov kamnin, kjer so predstavljeni tipicni predstavniki posameznih kamninskih skupin. Podrobneje so tipi kamnin razloženi pri obravnavanju pokrajin Slovenije, kjer sta podana natancna razclenitev in njihov nastanek. Pred­stavljena je povezava kamnin z nastankom raz­licnih tipov tal. Zelo skopo so opisani viri mine­ralnih surovin. Hidrogeološke vsebine se zacnejo z vodnim krogom in deležem posameznih tipov voda na Zemlji. Vsebine so navezane na onesna­ ževanje pitne vode. Pri obravnavanju geografije Slovenije je predstavljeno, kje v Sloveniji dobi­ mo pitno vodo ter opisano onesnaženje podzemne pitne vode. Kras je podrobno obravnavan v ce­lotnem poglavju o pokrajinah Slovenije. Vsebine ekologije in varstva okolja zajemajo analiziranje posledic posegov v okolje, izkorišcanja in prede­lave rud, posledice uporabe fosilnih goriv, pod­nebne spremembe in njihov vpliv na okolje. Velik del vsebin je namenjen trajnostnemu gospodarje­nju z okoljem in surovinami. Kljub vecjemu obse­gu vsebin so te naravnane na ucenje podatkov in niso zadosti usmerjene v razumevanje. To lahko pripišemo vsebinski zasicenosti predmeta. Zopet velja poudariti, da podobno kot v osnov­ni šoli tudi v gimnazijskih ucbenikih ni niti v enem primeru podana definicija geologije kot vede. Geološke vsebine in njihova zahtevnost na maturi Pregled maturitetnih izpitnih katalogov za predmeta Biologija (Bavec et al., 2015) in Geo­grafija (Balažic et al., 2014) nam je omogocil defi­niranje pricakovane stopnje znanja ob zakljucku srednješolskega izobraževanja. Geološke cilje, ki se preverjajo na maturi (Tabela 4), smo enako kot ucne cilje v ucnih nacrtih vrednotili po Bloomo­vi taksonomiji ter jih razvrstili na šest tematik. Zahtevnost ciljev je predstavljena pri vsaki te­matiki posebej (sl. 4). Tabela 4. Število ucnih ciljev pri posameznem predmetu na maturi, razvršcenih po tematskih sklopih. Table 4. Geological learning objectives classified by topics, for individual subjects on matura examination. Predmet/Tema Subject/Topic Osnove geologije Geology Basics Paleontologija Paleontology Petrologija/ Mineralogija Petrology/ Mineralogy Hidrogeologija Hydrogeology Kras Karst Ekologija/ Varstvo okolja Ecology/ Environmental protection Biologija Biology 2 7 0 0 0 1 Geografija Geography 33 0 5 9 4 4 12 10 8 6 4 2 0 Osnove geologije/Geology basic Paleontologija/Paleontology Petrologija/Mineralogija; Petrology/Mineralogy Hidrogeologija/Hydrogeology Kras/Karst Poznavanje/Knowledge Razumevanje/Comprehension Uporaba/Application Analiza/Analysis Sinteza/Synthesis Vrednotenje/Evaluation Ekologija/Varstvo okolja; Ecology/Environmental protection Sl. 4. Število ucnih ciljev, razvršcenih po tematskih sklopih, predstavljenih po stopnji zahtevnosti na maturi. Fig. 4. Number of geological learning objectives in matura examination, classified according to topics, presented by level of difficulty. Kar 64 odstotkov vprašanj je iz vsebin osnov geologije. Nanašajo se vecinoma na temo obli­kovanosti površja, sledijo vsebine regionalne geologije, energetike ter ostale, kjer je za razu­mevanje pomembno osnovno geološko znanje. Druga kategorija po zastopanosti je petrologija, ki je zastopana s 13 odstotki. Vprašanja se pre­težno navezujejo na maticno oziroma kamninsko podlago in nastanek tal na kamninah. Vsebine ekologije in varstva okolja zajemajo 11 odstotkov vprašanj, dotikajo se okoljskih problematik in so geološko naravnana. Sklopi hidrogeologija, kras in paleontologija se na maturi pojavljajo redko. Pri paleontologiji se pojavijo vprašanja o fosilih, evoluciji in nastanku življenja. Hidrogeološki sklop vsebuje vprašanja v zvezi s podzemno vodo in njeno povezavo s kamninsko podlago, iz tema­tike krasa pa se vprašanja nanašajo na nastanek in znacilnosti kraškega sveta. Vecina vprašanj doseže prvo taksonomsko stopnjo v kognitivni domeni – poznavanje. Sledi stopnja razumevanja, redkeje pa tudi analiza in sinteza. Stopnjo uporabe doseže malo vprašanj, nobeno vprašanje pa ne doseže stopnje vrednote­nja. Vecina ciljev v izpitnem katalogu, povezanih z geološkimi vsebinami, je zastavljena na višji ta­ksonomski stopnji zahtevnosti, kot so postavljena maturitetna vprašanja, ki te cilje preverjajo. Zastavljena vprašanja in pricakovani odgovo­ri so v 95 odstotkih strokovno ustrezni. Pri delno ustreznih, ki jih je 5 odstotkov, gre za problema­tiko razlicnega poimenovanja dolocenih pojavov. Neustrezno zastavljenih vprašanj ni. Medpredmetna povezanost in nadgradnja znanja po tematikah Izmed 141 prepoznanih ucnih ciljev z geološko vsebino sta bili nadgradnja in medpredmetna po­vezanost ugotovljeni pri kar 110 ciljih. Drugi so omejeni samo na spoznavanje s tematiko, njihov cilj pa je zgolj priklic dejstev. Z ugotovljeno med­predmetno povezanostjo pricakujemo, da lahko defi niramo tudi pricakovano stopnjo predznanja posamezne tematike, pri kateri je bilo ugoto­vljeno nadgrajevanje. V nadaljevanju podajamo teme, ki jih lahko geološke inštitucije, muzeji in posamezniki nadgrajujejo ter s svojimi dejav­nostmi zapolnjujejo ugotovljene vrzeli v znanju ucencev in dijakov. Z aktivnim vkljucevanjem v pripravo strokovnih in poljudnih clankov ter po­ucevanjem uciteljev pa prispevajo k višji stopnji prepoznavnosti geologije in strokovno pravilni predstavitvi za splošno javnost. S tem pripomo­rejo k nadgradnji znanja o podanih tematikah v družbi. R. BRAJKOVIC, M. BEDJANIC, N. MALENŠEK ANDOLŠEK, N. RMAN, M. NOVAK, K. ŠUŠMELJ & P. ŽVAB ROŽIC Vsebine iz osnov geologije zajemajo 52 odstot­ kov vseh ucnih ciljev z geološko vsebi no. Vsebine, kjer je bila ugotovljena medpredmetna poveza­nost, so: zgradba Zemlje in tektonika plošc, vu­lkani in potresi, oblikovanost površja, geološki razvoj Slovenije ter geološka karta. S sestavo Zemlje se ucenci in dijaki srecajo v 6. razredu pri predmetih Naravoslovje in Geo­ grafiji, kjer spoznajo prerez Zemlje. Tematika se ponovi na isti stopnji v 9. razredu pri predmetu Geografija. Na splošni gimnaziji je pri predme­tu Biologija predstavljen v pliv tektonike plošc na evolucijo, pri predmetu Geografija pa je znanje nadgrajeno s predstavitvijo natancnejše razcle­nitve notranjosti Zemlje z omembo diskontinu­ itet ter premikanja litosferskih plošc. Tematika se zakljuci na taksonomski stopnji razumevanja. Glede na vsebine v ucbenikih ocenjujemo, da so ucni cilji doseženi. Priložnost nadgradnje znanja je predvsem pri predstavitvi stikov litosferskih plošc, kjer ni zadostno opisana dinamika premi­kanja ter vpliv razlicnih stikov na oblikovanost površja. Vulkani in potresi so prvic obravnavani v 7. razredu pri predmetu Geografija. Vsebina zajema opis ognjenega obroca ob Tihooceanskih litosfer­skih plošcah ter primere v Južni Evropi. V splo­šni gimnaziji se pri predmetu Geografija vsebina nadgradi, saj morajo dijaki prepoznati razloge za nastanek potresov in vulkanov ter prikazati glavna potresna in vulkanska obmocja na svetu. Spoznajo tudi osnovne tipe vulkanizma. Temati­ka je mocno navezana na geološko pogojene ne­varnosti. Ce lahko ugotovimo, da je tema vulka­nizma prikazana korektno, pa se pomanjkljivosti pojavijo pri predstavljanju nastanka potresov. To je omejeno na tektoniko plošc in tako ni poda­na vsebina, ki bi jo posameznik lahko apliciral na naše obmocje. Ucni cilji so delno doseženi, a prostora za nadgradnjo je precej. Še posebej za­skrbljujoce je, da drugi, še pogostejši pojavi, kot npr. pobocni masni premiki, v formalnem izo­braževanju niso obravnavani na nivoju razume­vanja. Tako vecina pojavov geološko pogojenih nevarnosti ni zadostno razložena. Na tem mestu je zato še posebej pomembno poljudno informira­nje ucencev in dijakov. Oblikovanost površja je tematika, ki si jo ge­ologi delimo z drugimi vedami, ki se ukvarjajo s preucevanjem površja. Le-tej je med cilji, uvr­šcenimi v osnove geologije, namenjeno dalec naj­vec pozornosti. Na stopnji poznavanja se zacne obravnavati že v 4. razredu pri predmetu Družba. Pri predmetu Geografija pa se v 9. razredu in na splošnih gimnazijah mocno nadgradi. Pricakuje se, da so ucenci in dijaki sposobni razložiti nasta­nek današnjega reliefa. Razlaga procesov, ki vpli­vajo na relief, je prikazana skozi razlago zunanjih in notranjih dejavnikov, pri cemer je tektonika izpušcena ali omenjena zgolj bežno. Pricakuje se, da dijaki na podlagi kamninske zgradbe opišejo njen vpliv na oblikovanje površja. Tematika si­ cer doseže visok taksonomski cilj sinteze, cesar pa z vsebinami, predstavljenimi v ucbenikih, ni mogoce doseci. V ucbenikih so vsebine v mnogih primerih nestrokovno poenostavljena. Tako je ob­likovanost površja tematika, kjer bi lahko geologi z vkljucevanjem v poucevanje veliko pripomogli k zavedanju, da je za razumevanje oblike površja potrebno poznavanje dogajanja pod površjem in pravilno dojemanje tektonskih dejavnikov. Le tako bi se lahko dosegla stopnja razumevanja, ki je definirana v ucnih nacrtih. Vsebine o geološkem razvoju Slovenije se obravnavajo pri predmetu Geografija v 9. razre­du in v 3. letniku gimnazij. Ucni cilji so na osnov­nih stopnjah poznavanja in razumevanja, vsebine v ucbenikih pa so predstavljene na višji takso­nomski stopnji ter zelo površno poenostavljene. Strokovne netocnosti v ucbenikih so zelo pogos­te. Del ucnih ciljev pri tej tematiki je izbiren. Raziskava ucnih nacrtov v naravoslovju (Catana & Vilas Boas, 2017) je pokazala, da si jih ucitelji ne izberejo za poucevanje, saj se zanje pocutijo premalo strokovno podkovani. Tako lahko zak­ljucimo, da iz obstojecega gradiva brez dodatnih aktivnosti uciteljev ucni cilji ne morejo biti dose­ženi. Priložnosti za nadgradnjo so široke, od izo­braževanja uciteljev do poljudnih predstavitev in delavnic na to temo. Poznavanje in uporaba geološke karte sta v ucnem nacrtu opredeljena v 9. razredu in na gi­m naziji pr i pred metu Geografija. Uporaba geolo­ške karte je namenjena umešcanju v prostor. Od ucencev v osnovni šoli se pricakuje osnovno po­znavanje geološke karte, medtem ko se v gimna­zijah od dijakov pricakuje tudi sposobnost bra­nja karte ter njena uporaba pri terenskem delu. Osnove razumevanja geološke karte v analizira­nih ucbenikih niso razložene, zato iz obstojecega gradiva ucni cilji ne morejo biti doseženi. Nujna je poljudna in strokovno ustrezna predstavitev te tematike. Vsebine paleontologije zajemajo 6 odstotkov vseh ucnih ciljev z geološko vsebino. Tematiki, ki predstavljata medpredmetno povezanost, sta nastanek življenja in evolucija. Da bi postavili primerne osnove, je pomembna celostna predsta­vitev fosilov in fosilizacije. Te teme se pojavlja­jo zgolj kot razdrobljena snov v 5. razredu pri predmetu Naravoslovje in tehnika ter kasneje v 9. razredu in v splošni gimnaziji, pri predmetu Biologija. Nastanek življenja na Zemlji in evo­lucija sta obravnavana predvsem pri predmetu Biologija. V ucbenikih sta temi vecinoma pred­stavljeni razdrobljeno. Osredotocata se na velika izumiranja, nikjer pa razvoj življenja ni prikazan zvezno. Tematiki nastanka življenja in evolucije tako ne dosežeta primerne stopnje za razumeva­nje in kljub temu, da delno ustrezata zapisanim ucnim ciljem, ne ponudita pregleda nad temati­ko. Priložnosti nadgradnje znanja so tudi tukaj široke in potrebne. S podrocja petrologije in mineralogije je v uc­nih nacrtih definiranih 9 odstotkov izmed vseh geoloških ciljev. Ucenci se z minerali in kamni­nami srecajo prvic pri predmetu Družba v 4. ra­zredu, pri obravnavanju domace pokrajine. V 6. razredu so s to tematiko povezani prvi ucni ci­lji pri predmetu Naravoslovje. Ker je poznavanje mineralov kljucno za prepoznavanje kamnin, je zaskrbljujoce dejstvo, da se z lastnostmi minera­lov ucenci srecajo samo tukaj. Ta vsebina ni ra­zložena na primerni stopnji in je omejena zgolj na trdoto mineralov in Mohsovo trdotno lestvico. Prepoznavanje kamnin in njihova klasifikacija se tako skozi ves izobraževalni sistem obravnavata brez predhodno utrjenih osnov. V 6. razredu pri predmetu Naravoslovje in v 9. razredu pri pred­metu Geografija se vsebine obravnavajo na enaki stopnji in znanje se ne nadgradi. Cilji se zakljuci­jo na taksonomski stopnji uporabe, ta stopnja pa brez dobrih osnov ne more biti dosežena. Ucbeniki ponujajo korektno razlago procesov nastanka ka­mnin z manjšimi pomanjkljivostmi, vendar brez prakticnega dela ti cilji ne morejo biti doseženi. Zato je v ucnem procesu nujna uporaba šolskih geoloških zbirk (Rman, 2010a, b; Rman & Novak, 2016; Madronic, 2018). Te so pogosto neurejene in skrbniki zbirk nimajo potrebnega znanja za nji­hovo ureditev (Rman et al., 2014). Tematika ka­mnin je navezana na maticno podlago kot osnovo za nastanek tal. Cilji, povezani s tem delom, so v ucbenikih ustrezno predstavljeni in zadošcajo ucnim ciljem. Zaskrbljujoca je šibka predstavi­tev mineralnih surovin. Le delno so omenjene pri predmetu Naravoslovje v 6. in 7. razredu in pred­stavljene na nekaj primerih. Širše se obravnava njihovo izkorišcanje in negativen vpliv na okolje. Tematika se nadgradi v splošnih gimnazijah pri predmetih Biologija in Geografija. Vsebine v uc­benikih so zadostne za doseganje ciljev v ucnih nacrtih. Kljub odvisnosti sedanje družbe od mi­neralnih surovin, se ucni nacrti osredotocajo na primere iz preteklosti, ko so rudniki in topilnice onesnaževali okolje. Današnja negativna konota­cija rudarjenja je predvsem posledica zastarelih vsebin v ucbenikih. Poucevanje bi moralo temelji­ti na primerih zaprtih zank recikliranja mineral­ nih surovin, a ta ideja v ucbenikih zaenkrat še ni predstavljena. Hidrogeologija zajema 9 odstotkov vseh ucnih ciljev z geološko vsebino. Poleg splošnih vsebin z vodnim krogom je medpredmetna povezanost ugotovljena pri podzemni vodi. Vsebine so obrav­navane pri predmetih Naravoslovje in tehnika v 5. razredu, Naravoslovju v 7. razredu ter na gim­ naziji pri predmetih Biologija in Geografija. Ucni cilji se pri prehodu iz osnovne šole na gimnazijo nadgradijo ter dosežejo taksonomsko stopnjo sin­teze. Dijaki naj bi bili sposobni preko kamninske zgradbe pojasniti nacine oskrbovanja s podzemno vodo v razlicnih delih Slovenije. Pri tem razlic­ni tipi vodonosnikov v ucbenikih niso zadostno razloženi. Pri razlicnih tematskih sklopih dija­ki spoznajo kraški vodonosnik, medzrnski tip pa kljub svoji pogostosti ni zadostno razložen. Vse­bine ne ponudijo zadostne razlage za sposobnost presojanja o tej tematiki. Onesnaževanje podze­mne vode je predstavljeno skladno z ucnimi cilji. V ucbenikih so pogoste terminološke napake pri poimenovanju podzemne vode, kajti izraz pod­talnica ni primeren. Primer dobre prakse, kako pristopati k nadgradnji geoloških ucnih vsebin in strokovni ustreznosti, je strokovni clanek Janže et al. (2017). Prostor za nadgradnjo je pri prikazu dinamike podzemne vode in ustrezni strokovni nadgradnji znanja uciteljev. Koraki v to smer so že narejeni (Rman, 2013) in lahko izboljšajo dose­ ganje zahtevane stopnje ucnih ciljev. Kras je z neposrednimi ucnimi cilji definiran v splošnih gimnazijah in predstavlja 4 odstotke vseh ucnih ciljev z geološko tematiko. Predhodno se poucuje kot del obravnavanja površja Sloveni­je pri predmetu Geografija v osnovni šoli. Tako naj bi dijaki znali razložiti nastanek krasa, opisa­ti površinske in podpovršinske kraške oblike ter utemeljiti ranljivost krasa za onesnaženje. Vsebi­ne so predstavljene natancno in strokovno ustre­zno ter zagotavljajo dovolj podlage za razumeva­nje na zahtevani taksonomski stopnji uporabe. Vsebine ekologije in varstva okolja so v ucnih nacrtih zelo zastopane in predstavljajo kar 20 od­stotkov vseh ucnih ciljev, povezanih z geologijo. Povprecna zahtevnost tematike je najvišja med vsemi definiranimi tematskimi sklopi in doseže povprecno taksonomsko stopnjo uporabe. Med­predmetna povezanost je bila znotraj teme ugo­tovljena pri tematikah o obnovljivih in neobno­vljivih energetskih virih ter vplivu izkorišcanja R. BRAJKOVIC, M. BEDJANIC, N. MALENŠEK ANDOLŠEK, N. RMAN, M. NOVAK, K. ŠUŠMELJ & P. ŽVAB ROŽIC mineralnih surovin na okolje. Prvi so predstavlje­ni pri predmetu Naravoslovje v osnovni šoli ter pri Biologiji in Geografiji na gimnaziji. Vsebine v ucbenikih ustrezajo ciljem v ucnih nacrtih. Za­postavljena je predstavitev geotermalnega po­tenciala, ki je omenjena zgolj pri predmetu Geo­ grafija. Ucenci in dijaki dobijo vpogled v slabosti prekomernega izkorišcanja fosilnih goriv, spoz­najo njegove posledice in so sposobni presojati o primernih nacinih uporabe energetskih virov. Ne spoznajo pa geoloških naravnih vrednot in pome­na njihovega varovanja. Priložnosti za nadgra­dnjo gradiva in znanja so tudi tu številne. Geološke vsebine se pojavijo tudi pri pred­metu Kemija v osnovni (Bacnik et al., 2011) in srednji šoli (Bacnik et al., 2008). Ucnih ciljev z geološko tematiko ni, omenijo se kot izhodišce za povezavo znanja. Medpredmetne povezave so v osnovni šoli definirani z predmeti Naravoslov­je, Geografija in Biologija, v splošnih gimnazijah pa pri predmetu Geografija in Biologija. Vsebi­ne, kjer so v ucnih nacrtih definirane povezave z predmetom Kemija so: sestava zemeljske skor­je, ogljikovodiki, kraški pojavi, okoljski problem onesnaženosti podzemne vode, fosilna goriva in mineralne surovine. Primerjava z dosedanjimi študijami Raziskava predstavlja temelj za nadaljnje delo na podrocju trajnosti znanja. Narejena je bila že raziskava za predmete Slovenšcina, Zgodovina, Geografija, Biologija in Kemija, vendar geolo­ških vsebin ni zajela (Marentic Požarnik, 2001a, 2001b). Rezultati analize trajnosti gimnazijskega znanja kažejo, da so študentje z gimnazije ohra­nili zelo površinsko ter pogosto zelo nepopolno in napacno pojmovanje družbenih in naravnih pojavov. Zanimivo bi bilo na podlagi ugotovlje­ne stopnje predznanja narediti podobno analizo tudi za geološke vsebine. Predstavljena raziskava je izhodišce za ume­šcanje posodobljenih vsebin v ucne nacrte. Ob­stojece so pogosto pomanjkljive in strokovno ne-tocne. Dobili smo tudi vpogled v medpredmetno nadgrajevanje, ki je v trenutni obliki ucnih na­crtov zadostno, opozoriti pa gre na odsotnost predstavitve geologije kot vede. Tako se je pomi­slek, da bodo geološke vsebine zaradi nezadostne predstavitve pri ucencih in dijakih dojete kot ge­ografske (Majcen, 2003), verjetno že uresnicil. Kot opozarja že Popit (2005), smo tudi v pri­cujoci raziskavi prišli do ugotovitve, da je raba geoloških terminov pogosto neusklajena in nep­rimerna. To je še posebej izrazito pri vsebinah, katerih poenostavitev je zahtevnejša. Kot ugotavlja že raziskava ucnih nacrtov v vrtcih in na razredni stopnji osnovne šole, je ge­ ologija, ceprav je v ucnem sistemu ni, prisotna povsod, saj predstavlja bazo znanja in izhodišce za predmete, pri katerih se pojavljajo geološke vsebine (Zvonar, 2017). Podobno smo ugotovili tudi za predmetno stopnjo osnovne šole in splo­šne gimnazije. Vsebinsko je naša raziskava so­ rodna z raziskavo nacionalnih ucnih nacrtov v naravoslovju na Portugalskem, Norveškem in v Sloveniji, ki je bila narejena v okviru projekta ESTEAM (Catana & Vilas Boas, 2017). Avtorji pri projektu ESTEAM so z anketiranjem uciteljev ugotovili število ur, namenjenih poucevanju ge­oloških vsebin. Naša raziskava predstavlja kom­ plementarno nadgradnjo tega projekta, saj ucne cilje tudi vrednoti po taksonomski zahtevnosti in podaja povezavo z vsebino v ucbenikih. Raziska­vo smo dodatno razširili še na splošne gimnazije in splošno maturo. Zakljucek Z opravljeno raziskavo smo dobili sistematicen vpogled v poucevanje geoloških vsebin v osnov­nih šolah in v splošnih gimnazijah. Vrednoteni ucni nacrti ter geološke vsebine v ucbenikih in na maturi so omogocili pregled nad pricakovano stopnjo predznanja po koncanem srednješolskem izobraževanju. Raziskava je podala naslednje zakljucke: -Geološke vsebine se poucujejo v osnovni šoli pri obveznih predmetih Družba, Nar­avoslovje in tehnika, Naravoslovje, Geo­ grafija in Biologija ter izbirnem predmetu Okoljska vzgoja. Na splošnih gimnazijah se poucujejo pri predmetih Biologija in Geografija, kjer se znanje preverja tudi na splošni maturi. -Vseh ucnih ciljev z geološko vsebino je 141, takšnih, kjer je bilo ugotovljeno medpred­metno nadgrajevanje, pa kar 110. Razd­ robljenosti vsebin in posledicno nizka trajnost znanja je najverjetnejši vzrok za slabo stopnjo poznavanja geoloških vsebin v družbi. -Medpredmetno povezanih sklopov vsebin je 15. V ucbenikih so vsebine vecinoma strokovno ustrezne, vendar pa so glede na vrednotenje ciljev v ucnih nacrtih na nižji taksonomski ravni in kot takšne pogosto ne predstavljajo ustreznega temelja za dose­ganje ciljev. -Glede na opravljen pregled je ocitna odsot­nost nekaterih za družbo izjemno pomem­ bnih geoloških tematik. Pomanjkljiva je predstavitev tektonskih vplivov na oblik­ovanost površja, dinamika podzemne vode, ki doloca tudi lastnosti pitne vode in nacine njene zašcite, skoraj popolnoma je odsotna tematika geološko pogojenih nevarnosti in mineralogija, mineralne surovine imajo izredno negativno konotacijo. Ucenci in di­jaki v izobraževalnem sistemu dobijo pre­malo informacij o neposredni uporabnosti geološkega znanja. -Maturitetno preverjanje znanja je glede na zastavljena vprašanja skladno z izpitni­mi cilji. Opaziti je le taksonomsko odsto­panje, saj so bila vprašanja zastavljena na nižji taksonomski stopnji. Kar 95 odstotk­ov vprašanj je zastavljenih strokovno us­trezno, 5 odstotkov je vrednotenih kot del­no ustrezno, a le zaradi razlik v strokovni terminologiji. -Opravljena raziskava lahko pomaga pro­motorjem geologije kot znanosti in stroke. Nakazane so priložnosti, kje lahko s svo­jim delovanjem pripomoremo k izboljšanju trenutnega stanja poznavanja geologije kot vede. Kaže se tudi potreba po mocnejšem povezovanju in aktivnosti znotraj stroke, za namene promocije geološke vede v for­ malnem in neformalnem izobraževanju. K temu bi najbolj pripomogla priprava sa­mostojnega ucnega gradiva z geološko tem­atiko za osnovne šole in splošne gimnazije po najnovejših didakticnih metodah. -Anomalija, da Geologija kot predmet ni zastopana v osnovnih in srednjih šolah, a vsebinsko v ucnih ciljih vsesplošno definirana tako pri družboslovnih kot pri naravoslovnih predmetih, nakazuje na ne­ obhodno dejstvo, da je poucevanje geoloških vsebin osnova za razumevanje naravnih procesov na Zemlji in razvoja družbe. Nje­na predstavitev v ucbenikih je nezvezna, strokovno pomanjkljiva ter vsebinsko zelo okrnjena. To nam daje izhodišca za zacetek umešcanja posodobljenih in zvezno pred­stavljenih geoloških vsebin v formalno izo­ braževanje. Zahvala Zahvala gre Slovenskemu geološkemu društvu, ki je s financnim prispevkom omogocilo reproducira­nje ucbenikov. 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CC Atribution 4.0 License https://doi.org/10.5474/geologija.2018.018 Provenance and characteristics of the pavement stone from the courtyard of the Ljubljana Castle Izvor in znacilnosti kamna v tlakovcih na osrednjem dvorišcu Ljubljanskega gradu Kristina PEULIC1, Matevž NOVAK2 & Mirijam VRABEC3 1Linhartova 92, SI-1000 Ljubljana, Slovenia; e-mail: kristina.peulic@gmail.com 2Geological Survey of Slovenia, Dimiceva ulica 14, SI-1000 Ljubljana, Slovenia; e-mail: matevz.novak@geo-zs.si 3University of Ljubljana, Faculty of Natural Sciences and Engineering, Department of Geology, Aškerceva 12, SI-1000 Ljubljana, Slovenia; e-mail: mirijam.vrabec@geo.ntf.uni-lj.si Prejeto / Received 26. 10. 2018; Sprejeto / Accepted 18. 12. 2018; Objavljeno na spletu / Published online 20. 12. 2018 Key words: natural stone, pavers, Kukul gneiss, Ljubljana Castle, petrographic classification Kljucne besede: naravni kamen, tlakovci, Kukul gnajs, Ljubljanski grad, petrografska klasifikacija Abstract The pavement stone used in the central courtyard of Ljubljana Castle originates from the Kukul area northeast of the town of Prilep in Republic of Macedonia. Several pavers were badly damaged and partly replaced by two other natural stones, because the original stone from Kukul is no longer available on the market. The natural stone that is recently used as a replacement is commercially named “Bianco Sardo” and differs from original rock from Kukul in both, structure and composition. The advancement of the replacement of original pavers with “Bianco Sardo” is resulting in extremely uneven and disturbing appearance of the courtyard. The original Kukul stone used in the central courtyard of Ljubljana Castle is of metamorphic origin and belongs to gneisses. Two types of pavers were identified, the light coloured and the dark coloured varieties. They have similar mineral composition consisting of quartz, feldspars (orthoclase, microcline and plagioclases), minerals of the epidote group, micas (muscovite and biotite), titanite, zircon, clinopyroxene, kyanite, pyrite and calcite. Light coloured pavers have porphyroclastic, protomylonitic to mylonitic structures. Dark coloured pavers display gneissic structure, contain more quartz and epidote, less feldspars, and no clinopyroxene. They show intensive recrystallization and granoblastic textures. Both analysed rock types belong to the same rock massif, only that the blocks were extracted from various parts of the rock massif. The variations are due to the process of metamorphic differentiation, which resulted in segregation and separation of light and dark coloured minerals. In the past, the natural stone that was coming from Kukul, was known and classifyed as a type of granite. The rock that is used in the central courtyard of Ljubljana Castle is not granite but granitic gneiss, therefore, we assume that in the last stages of quarrying in the Prilep area, they were extracting also the metamorphic country rocks for some time. The broader area of Prilep belongs to the Pelagonian massif. Its thick metamorphic complex contains also granitoid (granodiorite) intrusives, which crop out in the Prilep anticline and used to be quarried at the locality of Kukul. According to national regulations of the Republic of Macedonia the area is now protected as a natural monument and further exploitation was no longer possible. Today, there is only one open granite exploitation field in the wider surroundings of Prilep, the locality of Lozjanska Reka–Kruševica and a few localities of gneiss-granites of high potential. It would be necessary to consider these solutions for the conservation-restoration of the Ljubljana Castle central courtyard instead of using an inappropriate stone replacement. Izvlecek Naravni kamen, s katerim je tlakovano osrednje dvorišce Ljubljanskega gradu, izvira iz obmocja Kukula, severovzhodno od mesta Prilep v Republiki Makedoniji. Ker prvotni kamen iz Kukula ni vec na voljo na tržišcu, so vec poškodovanih tlakovcev nadomestili z dvema nadomestnima vrstama naravnega kamna. Naravni kamen "Bianco Sardo", ki so ga nedavno priceli uporabljati kot nadomestek, se mocno razlikuje od prvotne kamnine iz Kukula, tako po teksturi kot tudi po sestavi. Z napredovanjem menjave originalnih tlakovcev s kamnino "Bianco Sardo" postaja videz osrednjega dvorišca Ljubljanskega gradu izrazito neenoten. Izvirni kamen iz Kukula, ki je bil uporabljen v osrednjem dvorišcu Ljubljanskega gradu, je metamorfnega izvora in pripada gnajsom. Locili smo dve vrsti tlakovcev, tlakovce svetle in temne barve. Imajo podobno mineralno sestavo, ki jo sestavljajo kremen, glinenci (ortoklaz, mikroklin in plagioklazi), minerali iz epidotove skupine, sljude (muskovit in biotit), titanit, cirkon, klinopiroksen, kianit, pirit in kalcit. Svetli tlakovci so porfiroklasticni, s protomilonitno do milonitno strukturo. Temno obarvani tlakovci imajo gnajsno strukturo, vsebujejo vec kremena in epidota, manj glinencev in nic klinopiroksenov. Zanje je znacilna intenzivna rekristalizacija in granoblasticna struktura. Obe analizirani kamnini pripadata istemu kamninskemu masivu, le da so bili bloki med izkopom ocitno odvzeti iz razlicnih delov kamnoloma. Razlike v teksturi in strukturi so posledica procesa metamorfne diferenciacije, ki je povzrocila segregacijo in locitev svetlih in temnih mineralov. V preteklosti je bil naravni kamen, ki je prišel iz Kukula, znan in klasificiran kot vrsta granita. Kamnina, ki se uporablja v osrednjem dvorišcu Ljubljanskega gradu ni granit ampak granitni gnajs, zato predpostavljamo, da so v zadnji fazi obratovanja kamnoloma pri Prilepu zajeli tudi metamorfne prikamnine. Širše obmocje Prilepa pripada Pelagonskemu masivu. Njegov debeli metamorfni kompleks vsebuje tudi granitoidne (granodioritne) intruzije, ki izdanjajo v Prilepski antiklinali in so jih lomili v kamnolomu Kukul. V skladu z nacionalnimi predpisi Republike Makedonije je obmocje zdaj zašciteno kot naravni spomenik in nadaljnje izkorišcanje ni vec mogoce. Danes je v širši okolici Prilepa samo eno pridobivalno omocje granita v Lozjanski Reki-Kruševici in nekaj obmocij granitnih gnajsov z velikim potencialom. Te rešitve bi bilo treba pretehtati tudi za rekonstrukcijo osrednjega dvorišca Ljubljanskega gradu, namesto da se uporabljajo že na pogled neprimerni nadomestni naravni kamni. Introduction The appearance and the purpose of the Lju­bljana Castle, located above the Ljubljana city center, have been changed several times since 1120, when Ljubljana and its medieval fortress were mentioned for the first time. Today the Lju­bljana Castle is regularly visited by national and foreign tourists, as it has become a cultural and social center where numerous events are organ­ized (Kralj, 2005). Within the castle walls and towers there is an inner courtyard, which is in central part paved with natural stone originating from Kukul area near Prilep in Republic of Macedonia (Žiga Miklavc, personal communication, October 17, 2017). Many factors influence the degradation of natural stone when used as pavers, and at Lju­bljana Castle one of the main reasons are me­chanical damages. Some of the pavers were dam­aged to the extent that they had to be replaced. To the knowledge of the authors, this has been done without professional conservation-resto­ration guidance, but rather as individual repair works. As the original natural stone from Kukul is not available since 2017, they started to use two different stone replacements. Unfortunately, one of them (“Bianco Sardo”; Žiga Miklavc, per­sonal communication, October 17, 2017) differs substantially in both, composition and structure from the original rock and is greatly disrupting the look of the courtyard itself (fig. 1). So far, from 10 to 15 pavers have been replaced, but the number of damaged pavers waiting for a replace­ment is still large and their number is increasing over time. The Kukul natural stone was known commer­cially as granite and obviously they are replac­ing Kukul granite with another type of granite named “Bianco Sardo”. The problem is that the rock from Kukul, which is used in the central courtyard in Ljubljana Castle, is not an igneous rock (granite) but displays obvious metamorphic structure. In this paper, we present detailed mineral­ogical and petrographic, textural and structur­al characteristics of original natural stone used Fig. 1. (a) View of the central courtyard of the Ljubljana Castle in moist weather conditions. The replaced stones in the central part are easy recognizable. They are significantly lighter and disturb the uniform appearance of the courtyard. (b) Typical mechanical damages on the pavers in form of cracks along the edges. (c) Example of inappropriate replacemets in the central courtyard of Ljubljana Castle. in pavers. Precise macroscopic observations in the field and microscopic analysis of 13 polished thin sections were performed and correct petro­ graphic classification of rocks used in pavers at the central courtyard of the Ljubljana Castle is defi ned. In order to compare these rocks with the original Kukul stone, the literature on the prov­enance, geological setting and petrology of the latter been studied. Materials and methods The macroscopic characteristics were ob­served on site. Original rock types as well as their macroscopic composition and structure were described and photo-documented. Types of damages and the current practice of repair works were listed and photographed. In the central courtyard of Ljubljana Cas­tle, several pavers were already replaced and stored in the Castle cellar. From the individual replaced pavers we cut the representative sam­ples that were used for further petrographic analysis. The collected samples were fi rst cut perpendicular to the observed structures. From the rock chips, 13 polished thin sections were prepared. Six thin sections from six samples of light coloured pavers (labelled as 1a, 2a, 4a, 5a, 6a, and 7a), and seven thin sections (labelled as 1b, 2b, 3b, 4b, 5b, 6b and 7b) from seven differ­ent samples belonging to a darker variation of Kukul stone were made. Petrographic analyses were carried out using the Nikon Eclipse E200 optical microscope in the plane polarized light. The thin sections were photographed using the Nikon DS-Fil camera and the NIS Elements Ba­sic Research program. Results Observed damages of the pavers and current state of repair Numerous mechanical damages of the pav­ers are clearly visible. In most cases, they are expressed as thin cracks along the edges and of the corners of pavers (fig. 2). Weathering along the cracks is commonly marked with intensive discoloration (fig. 2c). Some cracks only started to form, cutting only the surface of the pavers, while others cut deep into the pavers or even all the way through. In the latter case, the pavers will have to be replaced. In several places, individual pavers were al­ ready replaced by two other rock types (fig. 3). Since the natural stone from the original source Kukul is no longer available, they choose two different types of natural stones that are used as a replacement for the damaged pavers. At fi rst, the natural stones of unknown origin was used which is similar in appearance to the original rock f rom Ku k u l (fig. 3a – ma rked w ith a squa re). Recently, natural stone with a commercial name “Bianco Sardo” was applied as a replacement. It has a completely different appearance from the primary paving stone from Kukul, as well as to the previously used replacement rock of unknown origin, and is disrupting the uniform appearance of the central courtyard of the Lju­ bljana Castle (fig. 3a – marked with a circle and fig. 3b). “Bianco Sardo” which is quar ried in Italy is noticeably brighter, without coloration, and has different compositional and structur­al characteristics compared to original paving stones. It has typical igneous holocrystalline structure, is homogeneous and medium-grained with sizes ranging from one millimeter to two centimeters. Macroscopically recognizable min­erals are grayish quartz, white and brownish feldspars, muscovite, biotite, amphiboles and/ or py roxenes. Petrog raphic classi fication of rock with the commercial name “Bianco Sardo” is granite. Macroscopic characteristics of the original pavement stone From the macroscopic observation, original pavement stone may be divided into two groups, light coloured (fig. 4) and dark coloured pavers (fig. 5). Most rocks in this group display medi­um-grained porphyroclastic and protomylonit­ic to mylonitic structure (e.g. Trouw et al., 2010) (fig. 4b, c). Minor concentrations of femic min­erals in forms of seams or bands are commonly observable (fig. 4c). Occasionally, primary phan­eritic structure may still be recognized (fig. 4d), although quartz is obviously recrystallized and porphyroclasts of potassium feldspar show signs of rounding on the edges at closer inspection. In the light coloured variations, potassium feldspars and quartz prevail, and are responsible for the bright appearance and lighter colour of the rock (fig. 4a). Potassium feldspars form idiomorphic to hipidiomorphic crystals with sizes ranging from 5 cm to small crystals of only few mm in diameter. Other distinguishable minerals are quartz, form­ing nests or sometimes ribbons or just evenly dis­tributed crystals in the matrix, minerals of epidote group, and minor amounts of pyrite and garnets. In the dark varieties of pavement stone, the femic minerals are concentrated and segregated into lenses and bands resulting in a darker ap­ Fig. 2. Damages on original paving stones in for m of cracks along the cor ners (a–b) or edges of the pavers (c– e). In several cases, cracks propagate deep into the body of the pavers (d). pearance of the pavers (fig. 5). The segregation Microscopic characteristics of original pavement stone of femic minerals is forming gneissic structure, where bands formed during metamorphic dif-Light coloured pavers ferentiation often display complex deformation (figs. 5a–b). Most minerals are macroscopically All samples have heterogeneous texture and indistinguishable (fig. 5c), apart from minerals in contain approximately 36 % of quartz, 35 % of larger felsic bands and lenses, where pink potas-potassium feldspars represented by microcline sium feldspars, greyish quartz, minor grains of and orthoclase, 11 % of minerals from epidote pyrite and garnet may be recognized (fig. 5d). group (epidote, clinozoisite, and allanite), 4 % Fig. 3. Replaced pavers in the central cou rtyard of the Ljubljana Castle. (a) A natural stone with the commercial name “Bianco Sardo” (marked with a circle) and another natural stone of unknown origin (marked with a square). (b) The bright greyish appearance and the apparent magmatic texture of the natural stone “Bianco Sardo” are in strong contrast with the original coloured rock from Kukul. Fig. 4. Light coloured pavers used in central courtyard of Ljubljana Castle. (a) Potassium feldspars are giving the unique pinkish tint to the matrix of the rock, yellowish green colour is mostly from minerals of epidote group and thin black seams are due to minor femic minerals. (b) Mylonitic structure composed of porphyroclasts of potassium feldspar in the matrix of epidote, some femic minerals, and recrystallized quartz. Perfect delta clast of potassium feldspar is nicely visible on the right side, below the centre of the figure. (c) In some pavers, femic minerals are concentrated in seams or bands (lover part of the figure). (d) Igneous phaneritic structure is still clearly visible. Fig. 5. Dark coloured pavers used in central courtyard of Ljubljana Castle. (a–b) Typical gneissic structure and contrast of dark pavers in contact with light coloured varieties (top and bottom border). (c) Most minerals in dark coloured pavers are macroscopically indistinguishable. (d) Reddish minerals in the felsic lens composed of white feldspars and quartz correspond to garnets (Grt), dark spots are pyrite (Py). of plagioclase, 4 % of muscovite, 2 % of biotite which is partly chloritized and/or epidotized, 2 % of titanite, 2 % of calcite, and 1 % of each of min­erals: clinopyroxene, zircon, kyanite, and pyrite. Predominant polycrystalline and minor monocrystalline quartz is xenomorphic to hi­pidiomorphic and have uniform or undulatory extinction (fig. 6a). The latter is a result of re­covery processes, which in places progressed all the way to the dynamic recrystallization (fig. 6a). Quartz either appears in recrystallized bands or surrounds feldspar and clinopyroxene porphyroclasts. In places, granoblastic texture is observable (fig. 6b). Among feldspars, micro-cline forms the largest crystals in all six thin sections, reaching 0.2 to 4.3 cm in length. They are xenomorphic and rounded on the edges due to the process of dynamic recrystallization (fig. 6c). Microcline is frequently twinned representing a rigid porphyroclast in an intensively recrystal­lized quartz matrix forming a protomylonitic to mylonitic texture (fig. 6c). Orthoclase also forms porphyroclasts, which are mostly xenomorphic and often twinned, with sizes ranging from 0.1 to 2 cm (fig. 6d). In some parts, orthoclase crystals show albite exolution lamellae and correspond to orthoclase perthite (fig. 6d). Plagioclases are smaller, reaching 0.02– 0.1 cm in average. They are present as individual xenomorphic crystals randomly distributed within the recrystallized quartz matrix (fig. 6e), together with muscovite and minerals from epidote group. As bigger crys­tals, they appear in the role of porphyroblasts or poikiloblasts (fig. 6e). Epidote group minerals are common and most typically occur in green, brown or mustard yellow colours. Epidote and clinozoisite form needle like and prismatic minerals in the matrix (figs. 6e, f), with sizes from 0.02 to 0.75 mm. Another epidote representative occurs in bigger isolated minerals with deep brown colour and distinct zoning, which are up to 1 cm long and most probably correspond to allanite (fig. 6f). Micas show strong parallel orientation and segregation in seams and bands Fig. 6. Microphotographs of light coloured pavers. (a) Mono and polycrystalline quartz showing signs of recovery and recrystallization together with small elongated muscovite and minerals from epidote group. (b) Oriented muscovite is for­ ming foliation. Quartz on the right-hand side is mostly idiomorphic, recrystallized and forming granoblastic texture. Higher relief prismatic minerals belong to epidote and clinozoisite. (c) Twinned microcline is forming a porphyroclast in intensively recrystallized quartz matrix forming protomylonitic to mylonitic texture. Microcline is rounded due to the recrystallization along the edges. (d) Porphyroclast of orthoclase-microperthite lies bellow the segregation of muscovite and some epidote group minerals defining foliation of the rock. (e) Individual plagioclase crystal in quartz matrix together with muscovite, biotites and epidote group minerals. Plagioclase poikiloblasts are full of small mineral inclusions. (f) Prismatic epidote group minerals in matrix and isolated crystal of allanite, in the centre of the figure. All figures were taken under crossed polars. Mineral abbreviations are according to Whitney & Evans (2010). Fig. 7. Microphotographs of dark coloured pavers. Quartz is a predominant mineral. Intensive dynamic recrystallization resulted in granoblastic texture. (a) Granoblastic polygonal texture where the equidimensional quartz has well developed cr ystal faces resulting in straight grain boundaries; the triple junctions are common. Minerals with higher interference colors belong to muscovite, biotites, clinozoisite, and epidote (note the zoning). (b) Granoblastic interlobate texture where quartz grain boundaries are mostly irregular (lover left-hand side of the figure). The segregation of muscovite and biotite in the central part of the figure is forming foliation. (c) Idiomorphic titanite in quartz with granoblastic amoeboid texture, the rest of the minerals are xenomorphic. The dynamic recrystallization is not complete and in several places, signs of recovery are still visible. Minerals with higher interference colours are muscovite and epidote. (d) Deformed microcline porphyroclasts are replaced by dynamically recrystallized quartz along the edges. (e) Large epidote grains with small pyrite inclusions next to idiomorphic brown coloured allanite with slight zoning. The rock is composed mostly of dynamically recrystallized quartz with rare small micas and epidote group minerals. (f) Xenomorphic zoned allanite partly altered along the rim. Slightly chlo­ ritized biotite (lower part of figure) and epidote are also recognizable. Figures (a–d and f), were taken under crossed polars. Figure (e) was taken under plane polarized light. Mineral abbreviations are according to Whitney & Evans (2010). resulting in pronounced foliation (figs. 6b, d). Muscovite has typical flaky appearance with siz­es ranging from 0.10 to 0.8 mm. Biotites are of­ten replaced by chlorite and/or epidote; therefore, they are unusually green, rarely brown, in colour. Biotites are a bit less common and smaller in size compared to muscovite, reaching maximal size of 0.6 mm, but they are mostly much smaller. Titanite is hipidiomorphic to idiomorphic, frequently with rhombic form and 0.02 to 1 mm in size. It can occur as individual crystals in ma­trix or as inclusions in feldspars, epidote, and kyanite. Clinopyroxenes are hipidiomorphic and 0.02 to 0.75 mm in size. They occur as individu­ al matrix minerals (fig. 6f). Small zircons do not exceed 0.08 mm in diameter, are mostly round­ed and are heterogeneously distributed in the matrix or as inclusions in biotite. Rare kyanite minerals are present in hipidiomorphic form and are full of inclusions, mostly belonging to titan­ite. Their average size is 0.8 mm. Pyrite occurs in xenomorphic crystals, only seldom it is found in idiomorphic forms with well-developed cr ystal faces of a cube. Pyrite crystal size ranges from 0.05 to 0.45 mm. Pyrite is often limonitized and display partly transparent red coloured edges. Calcite occurs as secondary mineral phase, is xenomorphic and is reaching 0.10 to 1.25 mm in size. It is found in form of filling in thin veins or as accompanying mineral together with quartz in matrix around bigger feldspar porphyroclasts. Dark coloured pavers All samples display inhomogeneous texture, which show signs of intensive dynamic recrystal­lization processes. Quartz is the most abundant mineral in all samples, making up to 50 % of the rock. The other constituents are represented by epidote group minerals (18 %), feldspars (17 %), micas (at 8 %), and the remaining 7 % belong to titanite, calcite, zircon, kyanite, and pyrite. Quartz is predominant mineral in all sam­ples. Its extinction is mostly uniform and rarely undulatory. It shows signs of intensive dynamic recrystallization that resulted in different types of granoblastic texture (figs. 7a–c). Feldspars be­long to orthoclase, microcline, and plagioclase series and have average size of 0.70 to 2.5 mm. Orthoclase and microcline porphyroclasts are usually deformed and appear rounded or with irregular boundaries due to the replacement by unstrained dynamically recrystallized quartz grains (fig. 7d). Plagioclases are mostly smaller, up to 0.7 mm, contain numerous small mineral inclusions and represent poikiloblasts. Minerals of epidote group belong to epidote, allanite and clinozoisite. Clinozoisite mainly forms individ­ual elongated prismatic crystals in the matrix. Epidote size ranges from 0.02 to 3.5 mm and fre­ quently shows zoning (fig. 7b). Allanite forms big distinctive brown coloured porphyroblasts, fre­quently with idiomorphic forms. They are reach­ing up to 3 mm in length and display distinctive zoning (fig. 7e–f). Micas occur as elongated flaky crystals, 0.1 to 0.75 mm in size, and are heterogeneously distrib­uted thorough the rock. Often they are segregat­ed and concentrated in lenses and layers and are forming gneissic foliation (fig. 7b). Micas are rep­resented by muscovite and minor biotites. Biotites are inferior and commonly replaced by epidote and chlorite. They contain inclusions of small zircon. Titanite is hipidiomorphic to idiomor­phic with well-developed rhombic cross-sections (fig. 7c). Individual titanite crystals range in size from 0.10 to 1 mm and occur in matrix or as in­clusions in other minerals, mainly kyanite. Zir­con was found as small idiomorphic inclusions in biotite or as dispersed crystals in the matrix. Zir­con size ranges from 0.05 to 0.1 mm. Rare xeno­morphic kyanite crystals do not exceed 0.8 mm. Pyrite is mostly idiomorphic and 0.08 to 0.1 mm in size. Rare xenomorphic grains of calcite occur and are up to 0.5 mm in size. They are found in parts composed of plagioclase and quartz. Discussion Petrografic characterization of “Kukul granite” used in the central courtyard of Ljubljana Castle The stone used in pavers displays macroscop­ically recog nizable g neissic str ucture, which is a result of metamorphic differentiation. During the metamorphic processes, the dark coloured minerals become segregated into distinct bands, which may be straight or bent. The intensive dy­namic recrystallization of the matrix in porphy­roclastic parts of the rock resulted in the forma­tion of protomylonitic to mylonitic texture. The average mineral composition of the rock used for pavers in the central courtyard of Lju­bljana Castle is 43 % of quartz, 28 % of feldspars, 14 % of minerals from the epidote group, 7 % of micas and 8 % of other minerals (Table 1). Based on mineral composition and texture characteris­tics, the investigated specimens of original rock are classified as gneisses (Winter, 2014). For the purpose of possible future restora­tion-conservation works, we distinguished two rock varieties: the light coloured and the dark Table 1. Mineral composition of the rocks used in the pavement stone of the central courtyard of the Ljubljana Castle. Mineral abbreviations are according to Whitney & Evans (2010). Mineral Qtz Kfs Pl Ep Ms Bt Ttn Zr Cpx Ky Py Cal Average composition (%) 43 25 3 14 5 2 2 1 1 1 1 2 Light colored pavers (%) 36 35 4 11 4 2 2 1 1 1 1 2 Dark colored pavers (%) 50 15 2 18 6 2 2 1 0 1 1 2 coloured pavers. Both have similar mineral com­position, but the proportions between individual minerals are different (Table 1). In light coloured pavers, porphyroclastic, protomylonitic to mylo­nitic structures are present, while in dark colour­ed pavers gneissic structure is predominant. Samples of dark coloured pavers with regard to light coloured varieties contain more quartz and epidote and less feldspars, and have no clinopy­roxene. They also display more intensive recrys­tallization that is obvious from common triple junctions, polygonal quartz and frequent grano­blastic textures. In several pavers the transitions between the light and dark variation of natural stone are displayed. These transitions are either sharp or gradual and mostly correspond to the transition between light coloured and undifferentiated to dark coloured and intensively metamorphical­ly differentiated rock. Therefore, even though we considered paving stones as two varieties of rocks, we have to bear in mind that this is the same rock, except that the blocks were obviously taken from various parts of the rock massif dur­ing the extraction. The variations within the rock massif are the result of the metamorphic differ­entiation, which resulted in the formation of var­ious textures due to the segregation and separa­tion of light and dark coloured minerals. Osojnik (2016) studied the radioactivity of 69 samples of the most used natural stone in the Re­public of Slovenia, including samples of Kukul granite. Based on his petrographic observations the Kukul granite is uniform with igneous tex­ture and containes 55 % feldspars, 30 % quartz, 13 % micas, 1 % of epidote minerals and 1 % hornblende, and was classified as monzogran­ite (Osojnik, 2016). Compared to the samples of “Kukul granite” taken from the Ljubljana Castle courtyard, the proportions of minerals are dif­ferent, the texture of the rock is obviously met­amorphic and the variability of the used natural stone is high. It is obvious, that the rock described by Oso­jnik (2016) and rock type used for pavers in the central courtyard of Ljubljana Castle are dif­ferent, although both have the same commer­ cial name (Kukul granite) and are classified as granite in the market. Although manufacturers of finished products are obliged to demonstrate and ensure the consistency of their products, in the case of Kukul stone, they clearly failed. We assume that in the process of stone extraction in the quarry area, they started to extract not only the granite/granodiorite massif but also the country rocks, which are gneisses with complete­ly different physical, mechanical and aesthetic characteristics. The provenance of the pavement stone in the central courtyard of Ljubljana Castle Locality Kukul is situated northeast of the town of Prilep in Rebublic of Macedonia in the direction of Drenova and towards Prisad and Dolneni, at an altitude of 953 m. The stone that has been quarried there under the commercial name Kukul granite is also known as Kukulj or Prilep granite. According to national regulations of the Re­public of Macedonia (the Law on Protection of the natural values since 1965), the Kukul area as part of the Prilep granite complex has been pro­tected as an area of exceptional natural phenom­ena so that the state nullified the previous con­cession for the exploitation of the architectural stone (Kurtovic, 2018). The area of Kukul belongs to the Pelagonian massif, a relic of the Precambrian Earth crust in this part of the Dinaric-Helenic belt, also known under the name Pelagonian horst anticlinorium. This large NW–SE-trending, NW-plunging an­ticlinorium with high-grade metamorphic core consisting of amphibolite grade gneiss, augen gneiss, and schist formed from protoliths of Pre­cambrian metasedimentary rocks. The complex is characterized by a thick section of marble in the upper part that partly frames the anticlinorium, and abundant granitic plutons, and is separat­ed from its neighbouring tectonic units by deep regional faults (Rakicevic et al., 1965a; Dumur­dzanov et al., 2005). The metamorphic complex of the Pelagonian Massif in general (according to Arsovski, 1960 and Stojanov, 1960, 1974), can be subdivided into: a) the lower metamorphic com­plex composed of the lowest series of gneiss and granites-granodiorites and the superpositioned series of micaschists; and b) the upper metamor­phic complex composed of the so-called mixed series and series of massive marbles. The mixed series, in general, is built from the albite-augen gneiss, white marbles and meta-rhyolites, while the series of the massive marbles is composed of dolomite, dolomite-calcite, and calcite marbles. In the lower complex, that is, in the series of gneisses, granitoid intrusions are found around Prilep, while in the surrounding region (for ex­ample at the contacts of these granitoids and mi­cashists), amphibolites and amphibolite-eclog­ites occur. The upper metamorphic complex lies concordant on the lower metamorphic complex with a sharp boundary between them (Jancev & Anastasovski, 2004). It is believed that the metamorphic crystalline rocks (gneisses, micaschists, marbles and oth­er regional metamorphic complexes) are about 1,500–720 million years old continental base­ment (Upper Proterozoic-Cambrian). These rocks have been intruded by granitoid magma proba­ bly about 250–300 million years ago during the Variscan orogeny (Jancev & Anastasovski, 2004; Schenker et al., 2014). Thus, the basic structural characteristics of the metamorphic phase in the Pelagonian massif are the result of syngenetic processes of high regional metamorphism and folding with plastic flow mechanism and contem­poraneous intrusion of granodiorites of the fi rst phase when large fold structures were formed (Arsovski, 1997; Spasovski & Dambov, 2011; Schenker et al., 2014). Granitoid complex of Prilep is structurally a part of Prilep anticline, which covers about 65 km2 in the territory north of Prilep (Arsovski, 1960; Rakicevic et al., 1965a, b) (fig. 8). A large part of this structure is composed of massive coarse-grained or locally porphyroid granodi­orite-adamelite (quartz monzonite). In between are rare occurrences of enclaves of various old schists in the granite. The length of the Prilep Fig. 8. Geological map and cross-section of the area of Prilep granitoids. Crop out from the Sheet Prilep of the Basic Geological Map 1: 100 000 (Rakicevic et al., 1965a). granodiorit-adamelite massif is about 8–9 km while the width is about 8 km. The contacts of the granite with the surrounding metamorphic rocks are accompanied by the granodiorite-ad­amelite sills and dykes. These contact zones are from about 10 to a few tens of meters wide and characterized by severe feldspatization in the surrounding rocks as well as other mineralogi­cal manifestations (e.g. quartzites, epidotization, etc.) (Stojanov, 1974). Suitable replacment pavement stone for conservation-restoration The natural stones used for pavers in the important areas, like in the central courtyard of the Ljubljana Castle, should be durable and available for longer period, because only in this way the uniform appearance of the area can be maintained. This should be taken into account when important buildings and/or their parts are exposed to extensive conservation-restoration works in modern times. W hen the stone from original quar r y is not available on the market anymore, suitable re­placement must be provided. It is suggested to fi rst check the areas nearby the original quar­ry. In case that geological setting of the broad­er area is uniform, there is a great possibility to fi nd a proper replacement stone in the vicinity in the quarr y that is situated in the same geologi­cal unit (even if it is across the state border). If we have to fi nd a replacement stone for conser­vation-restoration from the set of foreign rocks, then we must fi nd a rock that will mimic the original rock in its composition and structure as much as possible. Therefore, basic mineralogi­cal and petrological analyses and proper petro­graphic classification should be the rule and not the exception. Unfortunately, in most cases, the repair works are carried out without proper con­ser vation-restoration guidance or any geological support and the result is what we can see in the central courtyard of Ljubljana Castle. A differ­ent ty pe of granite (“Bianco Sardo”) replaces the commercially named “Kukul granite”, which is not a granite but gneiss. Because these two rock types differ much in the texture and in the quan­titative mineral composition, it is not a surprise that the advancement of the replacement ver y much disrupts the unifor m appearance of the central courtyard of the Ljubljana Castle (fig. 1). The Faculty of Civil Engineering of the Uni­versity of Sarajevo faced the same problem pre­paring the requirements for conservation-res­toration of the prominent Square of Bosnia and Herzegovina in front of the Bosnia and Herze­govina Parliament building in Sarajevo (Kur­ tovic, 2018). There, the pale rose to light brown paving tiles of Kukul granite were originally used in combination with dark Jablanica gab­ bro. Based on the detailed petrographic analysis of the pavers, the stone was identified as granite with the remark that due to the small amount of plagioclase, it could also be determined as gran­odiorite, but only after its chemical examination (Kurtovic, 2018). The only open granite-granitic gneiss ex­ploitation field in the wider surroundings of Prilep is the locality of Lozjanska Reka–Kr uševi­ca in the area of Mariovo, south-east of Prilep. There, the surface exploitation of granite/gran­odiorite is producing stone commercially called Mariovo-Krin. The field investigation of the area showed that Kukul-Prilep and Mariovo-Krin represent quarries within the same geological unit. After the physical-mechanical analyses of the Mariovo-Krin stone has shown its high quality, this stone was approved for use as a re­placement stone of on the Bosna and Hercegovina Square (Stojkov & Spasovski, 2014; Spasovski & Spasovski, 2015; Kurtovic, 2018). This solution is necessary to be considered also for the replacement of the pavers in the central courtyard of Ljubljana Castle, however it might prove not to be applicable, due to our results that the “Kukul granite” there is in fact gneiss. According to the descriptions of other natu­ral stones in the area of Prilep (in the Pelagonian massif) (Boev, 2006), the granitic gneiss from the locality of Mramorani is very promising. The lo­cality is situated some 6 km north-west of Prilep in close proximity to the village of Mažuciste. Macroscopically this gneiss-granite possesses or­namental look with white-creamy-greenish color. The mineralogy of the rocks consists of quartz, potassium feldspars (orthoclase, anorthoclase, microcline), acid plagioclases (albite to andesine), muscovite, biotite, apatite, rutile, titanite, ilmen­ite, zircon and epidote (Boev, 2006). Conclusions Based on mineralogical, petrographic, tex­tural and structural characteristics of original natural stone used in pavers as well as literature data on provenance and geological setting we can make the following conclusions: 1. Present appearance of the central court­yard of Ljubljana Castle is uneven and dis­rupted because the original pavement stone, from the Kukul area northeast of the town of Prilep, is not available any more for conser­vation-restoration works. They are replacing it, without professional conservation-resto­ration guidance, with inappropriate replace­ment granitic rock with commercial name “Bianco Sardo” originating from Italy, which is completely different in colour, structural and compositional characteristics. 2. The original pavement stone contains on av­erage 43 % of quartz, 28 % of feldspars, 14 % of minerals from the epidote group, 7 % of micas and 8 % of other accessory minerals. Based on the composition and structural characteristics it belongs to granitic gneiss. 3. Two types of pavers are recognized, the light and the dark rock types. They have similar mineral composition, only the proportions of the minerals are different; dark colour­ed pavers contain more quartz and epidote, less feldspars, and no clinopyroxene. Light coloured pavers have porphyroclastic, prot­omylonitic to mylonitic structures and dark coloured pavers display gneissic structure. The processes of dynamic recrystallization are more intensive in the dark coloured rock. Since in several pavers transitions between the light and dark rock types are displayed, we assume that this is in fact the same rock, but extracted from various parts of the struc­turally uneven rock massif. The obtained variations are the result of metamorphic dif­ferentiation, which produced the segregation and separation of light and dark coloured minerals. 4. Natural stone coming from Kukul (Republic of Macedonia) was known as a type of granite and/or granodiorite on the market. The rock that is used in the central courtyard of Lju­bljana Castle is obviously gneiss, therefore, we assume that in the last stages of quarrying in the Prilep area, parts of the metamorphic counrty rocks were also exposed to quarry­ing activities. 5. Today, the only open granitic gneiss exploita­tion field in the wider surroundings of Prilep is the locality of Lozjanska Reka–Kruševi­ca and there are a few localities of granitic gneiss of high potential. It would be neces­sary to consider these solutions for conser­vation-restoration of the Ljubljana Castle central courtyard instead of using an inap­propriate stone substitutes. Acknowledgements Sample preparation costs were financially sup­ ported by the Slovenian Research Agency (Research Programmes Number P1-0195 and P1-0011) and the IGCP 637 Project – Heritage Stone Designation. References Arsovski, M. 1960: Some features of the tectonic structure of the central part of the Pelagonian horst-antiklinorium and its relationship with the Vardar zone. Trudovi na Geološki zavod, Fasc. 7, Skopje. (In Macedonian). Arsovski, M. 1997: Tectonics of Macedonia. Faculty of Mining and Geology, Štip: 306 p. (In Macedonian). Boev, B. 2006: Pelagonia Marble Valley. PREDA – Prilep Region Enterprise Development Agency: 44 p. Dumurdzanov, N., Serafimovski, T. & Burchfiel, B. C. 2005: Cenozoic tectonics of Macedonia and its relation to the South Balkan exten­sional regime. Geosphere, 1: 1–22. https://doi. org/10.1130/GES00006.1 Jancev, S. & Anastasovski, V. 2004: Granite complex near Prilep of natural scientific im­portance. 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Poro~ila Porocilo o I. strokovnem simpoziju o rudniku Sitarjevec Tea KOLAR-JURKOVŠEK Geološki zavod Slovenije, Dimiceva ulica 14, SI-1000 Ljubljana, Slovenia; tea.kolar@geo-zs.si, V Litiji je dne 20.9.2018 je potekal I. strokovni simpozij o rudniku Sitarjevec in srecanje rudar­skih mest, v okviru katerega so bile predstavljene aktivnosti ob ponovni oživitvi rudnika v razisko­valne, izobraževalne in turisticne namene. Simpo­zija se je poleg geologov, biologov, rudarskih stro­kovnjakov, muzealcev, pedagogov in predstavni­kov znanih rudarskih mest Litija, Zagorje, Idrija, Zrece in Crnomelj ter predstavnika iz Ceške repu­blike (Sanatorium EDEL, Zlaté Hory), udeležilo precej litijskih obcanov. Glede na to, da je bil Sitarjevec eden izmed najvecjih polimetalnih rudnikov v Sloveniji, je bil poudarek simpozija na mineralnem bogastvu in recentnih pojavih hitro rastocih limonitnih kapnikov v opušcenih rudniških rovih. Predsta­vljene so bile paleogeografske in paleoekološke razmere v obsežni recni delti in v kateri so pred vec kot 300 milijoni let v ekvatorijalnem pasu nadceline Pangea nastajale kamnine Sitarjevca. Njihovo poznokarbonsko starost dokazuje boga­ ta fosilna flora, ki je bila najdena v neposredni okolici rudnika. Pomemben prispevek simpozijskemu progra­ mu so prispevali biologi, ki so v rudniških rovih proucevali prisotnost žuželk, netopirjev in sledove bele kune, ki globoko v rudniške rove zahaja ob­casno. Del simpozija je bil namenjen recentnim geokemicnim raziskavam rudniških vod in vplivu rudarskih del in topilniške dejavnosti na razmere v okolju. Simpozijski materiali so zbrani v bogato ilu­ strirani publikaciji, ki jo je izdala obcina Litija. Ob koncu so si udeleženci simpozija ogledali turisticni del rudnika Sitarjevec, ki ga je obcina Litija uredila v delu izvoznega rova na južni stra­ni hriba Sitarjevec. Simpozij je bil dobra popotnica evropskemu projektu MINETOUR v okviru Programa sode­lovanja Interreg V-A Slovenija – Hrvaška 2014 -2020, v katerem je poleg rudnika Sitarjevec vklju­cen tudi premogovnik Labin na Hrvaškem. Hidrogeološki kolokviji v obdobju od 2016 do 2018 Mihael BRENCIC Oddelek za geologijo, Naravoslovnotehniška fakulteta, Univerza v Ljubljani, Aškerceva cesta 12, SI-1000 Ljubljana; e-mail: mihael.brencic@ntf.uni-lj.si Geološki zavod Slovenije, Dimiceva ulica 14, Ljubljana Hidrogeološki kolokvij je strokovni dogodek, ki se odvija proti koncu vsakega koledarskega leta. Organiziran je v sodelovanju med Oddel­kom za geologijo Naravoslovnotehniške fakul­tete Univerze v Ljubljani in Slovenskim komi­tejem mednarodnega združenja hidrogeologov -SKIAH. Dogodek pritegne vecje število ude­ležencev, študente, hidrogeologe iz prakse, stro­kovnjake iz razlicnih državnih ustanov in iz akademske sfere. Vsako leto se kolokvija udeleži okoli petdeset udeležencev iz cele Slovenije, po­gosto pa tudi gostov iz tujine. Namen hidrogeolo­škega kolokvija je seznanjanje strokovne javnosti z rezultati aktualnih hidrogeoloških raziskav in z odprtimi hidrogeološkimi problemi na obmocju Slovenije. Hkrati je namen kolokvija tudi sezna­njanje slovenske strokovne javno-sti z dosežki hi­drogeološke stroke v svetu. Tako kolokvij skoraj vsako leto gosti vabljene predavatelje iz tujine, praviloma so to strokovnjaki iz širše sosešcine Slovenije, s katerimi imamo slovenski hidrogeo­logi tudi najboljše povezave. V zadnjih treh letih, od leta 2016 do leta 2018, se je v okviru kolokvija zvrstilo enajst predavanj in nekaj spremljevalnih dogodkov. 9. hidrogeolo­ški kolokvij je potekal 20. decembra 2016. Sprva je bil dogodek v celoti namenjen predstavitvi regionalnega bilancnega modela GROWA-SI, ki ga je pripravila Agencija Republike Slovenije za okolje, žal pa smo morali organizatorji zaradi nenadne odpovedi glavnega predavatelja, avtor­ja nemškega modela GROWA, program kolokvija spremeniti. Od prvotne programske zasnove je na sporedu ostala le predstavitev Miša Andjelova z Agencije Republike Slovenje za okolje z naslo­vom: »Regionalni model napajanja vodonosnikov GROWA-SI; Uporaba regionalnega hidro(geo) loškega modela za izracun komponent vodne bilance v Sloveniji«. Temu predavanju je sledila predstavitev knjige »Groundwater recharge in Slovenia« (Napajanje podzemne vode v Sloveniji) na katero se je navezovalo tudi predhodno pre­davanje. Knjiga podaja sintezo bilancnih izra­cunov podzemne vode za obmocje celotne Repu­blike Slovenije in tako predstavlja prvo temeljito sistematicno študijo bilancnih komponet pod­zemne vode na obmocju celotne države. Sklopu, ki se je navezoval na vodnobilancni model GROWA-SI, je sledilo predavanje Barbare Cen­cur Curk z Oddelka za geologijo, ki je predstavi­la rezultate evropskega projekta Drink Adria. V projektu so sodelovale skoraj vse države, ki so na­stale na ozemlju nekdanje Jugoslavije ter države Jadransko Jonskega pasu Italija, Grcija in Alba­nija. Projekt se je ukvarjal s problematiko opre­delitve prekomejnih vodnih virov pitne vode in prekomejne dobave pitne vode. Poleg teoreticnih sklepov in prakticnih analiz ter interpretacij so bile pomemben del rezultatov projekta tudi in­vesticije na prekomejni infrastrukturi za oskrbo s pitno vodo. V okviru projekta Drink Adria je bila opravljena tudi podrobna analiza dolocanja in implementacije vodovarstvenih obmocij v vseh na projektu sodelujocih državah. To analizo je v kratkem predavanju z naslovom »Vodovarstvena obmocja – Mednarodni pogled« predstavil Miha­el Brencic z Oddelka za geologijo. Naslednji 10. hidrogeološki kolokvij je pote­kal 30. novembra 2017 in je bil izveden v Tednu Univerze v Ljubljani. Na tem kolokviju so bila predstavljena tri obsežnejša predavanja. Prvi dve predavanji sta predstavili rezultate dela na znan­stvenih magisterijih s podrocja hidrogeologije. V predavanju z naslovom »Vpliv geološke zgradbe na kemijsko stanje podzemne vode na primeru Pomurja« je Marina Gacin z Agencije Republike Slovenije za okolje predstavila temeljito sintezo vseh razpoložljivih hidrogeoloških podatkov na obmocju medzrnskega vodonosnika Pomurja. S pomocjo teh podatkov je pripravila karto poraz­delitve nitratov v podzemni vodi. V naslednjem predavanju je Branka Bracic Železnik iz javne­ga podjetja Vodovod Kanalizacija iz Ljubljane predstavila predavanje z naslovom »Dinamika podzemne vode sistemov vodonosnikov Iškega vršaja«. Iški vršaj je pomemben vir pitne vode za južno obrobje mesta Ljubljana, predvsem pa za naselja na južnem obrobju Ljubljanskega barja. Pri tem gre za navidez enostaven medzrnski vo­donosnik, za katerega pa so podrobnejše hidro­geološke raziskave v zadnjem desetletju pokaza­le, da je tok podzemne vode in njeno napajanje kompleksnejše od tega, kakor smo ta sistem ra­zumeli do sedaj. Zadnje predavanje z naslovom »Izkušnje in izzivi upravljanja s podzemno vodo v Srbiji in na Balkanu« je pritegnilo veliko po­zornost. Predaval je Zoran Stevanovic redni pro­fesor Oddelka za hidrogeologijo Rudarsko geolo­ ške fakultete Univerze v Beogradu, ki predseduje Komiteju za kraško hidrogeologijo Mednarodne­ ga združenja hidrogeologov in je avtor, soavtor in urednik številnih odmevnih clankov in knjig, predvsem s podrocja kraške hidrogeologije. Pro­fesor Stevanovic je najprej predstavil razvoj hi­drogeologije v Srbiji in njene glavne dosežke, nato pa se je dotaknil problematike globalne oskrbe s pitno vodo s poudarkom na kraških vodonosni­kih. Na koncu predavanja je predstavil rezultate pomembnih hidrogeoloških projektov na obmo­ cju Srbije in Crne gore. Po zakljucku predavanj je bila izvedena še skupšcina SKIAH. V letu 2018 je kolokvij prvic potekal v pre­novljenih prostorih Oddelka za geologijo na Aškercevi cesti, pred tem je, vse do vkljucno 10. kolokvija leta 2017, dogodek potekal v prostorih Oddelka za geologijo na Prulah. 11. hidrogeolo­ški kolokvij je bil izveden 29. novembra 2018. Ta kolokvij je bil v celoti posvecen problematiki vo­dovarstvenih obmocij. Na podrocju vodovarstve­nih obmocij imamo v Sloveniji dolgoletne in bo­gate izkušnje. Prva vodovarstvena obmocja so bila dolocena že pred drugo svetovno vojno, vse od sredine petdesetih let 20. stoletja, ko so bila opredeljena obmocja v današnjem smislu, pa se je metodika njihovega dolocanja intenzivno raz­vijala. Slovenska hidrogeologija je na podrocju implementacije in razvoja metodologije varova­nja virov pitne vode nedvomno v svetovnem vrhu. To pa ne pomeni, da ni možnosti za dopolnitve in korigiranje obstojece prakse. Prav temu je bil namenjen 11. hidrogeološki kolokvij. V skla­ du z uveljavljeno prakso je prvi nastopil gostu­ joci predavatelj iz tujine. To je bil tokrat Jochen Schlamberger, vodja Oddelka za geologijo in monitoring voda pri Koroški deželni vladi v Av­striji. V predavanju z naslovom »Varovanje virov pitne vode v Avstriji« je predstavil metodologi­jo dolocanja vodovarstvenih obmocij in postop­kov varovanja vodnih virov pitne vode v Avstri­ji. Nina Mali z Geološkega zavoda Slovenije je v predavanju »Vodovarstvena obmocja v Sloveniji – vceraj, danes in jutri« predstavila pregled trenu­tnega stanja vodovarstvenih obmocij na obmocju Slovenije, prikazala je njihovo prostorsko razte­ zanje in težave ter odprte probleme pri njihovem uveljavljanju v praksi. Branka Bracic Železnik je v predavanju »Vodovarstvena obmocja z vidi­ka javne službe oskrbe s pitno vodo« na prime­ru vodovarstvenih obmocij severno od Ljubljane prikazala probleme in izzive, s katerimi se sooca Javno podjetje Vodovod Kanalizacija, ki upravlja po številu prikljuckov z najvecjim vodovodnim sistemom v Sloveniji. Analiza tveganja onesnaže­nja podzemne vode je pomemben inštrument pre­soje vplivov posegov v prostor na vodovarstvenih obmocjih. Ceprav je to mehanizem, ki je name­njen zlasti preverjanju predlaganih rešitev, se je v zadnjih letih pokazalo, da je ta postopek pogosto neustrezno implementiran. Problematiko analize tveganj je v predavanju z naslovom »Analiza tve­ganja kot sestavni del varovanja vira pitne vode – odpr ta vprašanja in problemi« predstavil Miha­el Brencic. Hidrogeološki kolokvij se je zakljucil z okroglo mizo, ki jo je vodila Barbara Cencur Curk. Kot panelisti so sodelovali predavatelji, svoja mnenja pa so prispevali tudi ostali udele­ženci kolokvija. Razprava je oblikovala nekate­re smernice za nadaljnje delo. Tudi v letu 2018 je bila po zak ljucku kolokv ija skupšcina SK IA H, ki je za naslednje mandatno obdobje petih let izvo­lila novo vodstvo društva. Porocilo o 5. slovenskem geološkem kongresu, Velenje 3. – 5. oktober 2018 Matevž NOVAK & Nina RMAN Geološki zavod Slovenije, Dimiceva ul. 14, SI-1000 Ljubljana; e-mail: matevz.novak@geo-zs.si Letos mineva 16 let od prvega kongresa slo­venskih geologov, ki se je v organizaciji Geolo­škega zavoda Slovenije in Slovenskega geolo­škega društva odvijal v Crni na Koroškem. Že ob prvem nas je presenetil odziv, ki je pokazal, da je geološki kongres zaželen in potreben dogodek, saj omogoca predstavitev rezultatov znanstvenih raziskav z neposredno izmenjavo mnenj in izku­šenj. Skozi leta je kongres rasel tako po številu udeležencev in predstavitev, kot obravnavanih tematik. Žal je bil od kongresa do kongresa opa­zen osip udeležbe predvsem tistih strokovnjakov, ki geološka znanja uporabljajo pri aplikativnem delu ali pa so koncni uporabniki rezultatov geo­loških raziskav. Organizacija in cilji Organizatorja 5. slovenskega geološkega kon­gresa, Geološki zavod Slovenije (GeoZS) in Slo­vensko geološko društvo (SGD), sta si za enega od glavnih ciljev zadala, da bi ta kongres poleg svojega osnovnega namena, predstavitev razi­skovalnih dosežkov slovenskih in tujih geologov, prispeval tudi k premošcanju vrzeli in podiranju zidov med znanstveniki in strokovnjaki ter med geologi in snovalci politik ter najširšo javnostjo. V ta namen sta za prizorišce kongresa izbrala Velenje, mesto, ki živi z geologijo in v katerem obratuje še zadnji slovenski premogovnik, in k organizaciji kongresa povabila sorodne inštitu­cije in društva ter lokalne partnerje: Premogov­nik Velenje (PV), Fakulteto za gradbeništvo in geodezijo (FGG), Slovensko rudarsko društvo in­ženirjev in tehnikov (SRDIT), Društvo slovenski komite mednarodnega združenja hidrogeologov (SKIAH) in Mestno obcino Velenje (MOV). Udeležba, teme in prispevki Na 5. slovenskem geološkem kongresu, ki je potekal med 3. in 5. oktobrom 2018 v Hotelu Paka v Velenju, je sodelovalo 191 udeležencev iz 18 držav. Med prijavljenimi iz tujine so bili go­stje iz Hrvaške, Albanije, Avstrije, Belgije, Bosne in Hercegovine, Crne gore, Islandije, Madžarske, Makedonije, Nemcije, Poljske, Portugalske, Re­publike srbske, Rusije, Slovaške, Švice, Velike Britanije in ZDA. Predstavljenih je bilo 169 prispevkov, od tega 112 predavanj in 57 posterjev. Predstavitve so bile razvršcene v 12 sekcij in so obsegale naslednja podrocja: regionalna geologija, stratigrafija, mi­neralogija, petrologija, sedimentologija, paleo­ntologija, strukturna geologija, tektonika, seiz­mologija, geologija kvartarja, geologija krasa, geokemija in okolje, hidrogeologija, geotermija, inženirska geologija, geotehnologija, mineralne surovine, materiali, geoenergenti ter geologija v šoli in širši javnosti. V sekciji Gospodarjenje z mineralnimi surovinami in varovanje podzemnih voda so sodelovali predstavniki ministrstev, dve sekciji z mednarodno zasedbo pa sta pote­ kali pod okriljem mednarodnih združenj; ena pod okriljem Komisije za mineralne in termal­ ne vode Mednarodnega združenja hidrogeologov (IAH CMTW) in druga pod okriljem Skupnosti znanja in inovacij (KIC) EIT RawMaterials. Na razpisanem natecaju za najboljše predstavitve smo podelili tri nagrade za najboljše posterske predstavitve in nagrado za najboljšo študentsko predstavitev. Nagrade za posterske predstavitve so prejeli Lan Zupancic s soavtorji (1. mesto), Nina Valand s soavtorji (2. mesto) in Tea Nova­ kovic s soavtorji (3. mesto). Nagrado za najboljšo študentsko predstavitev pa je za predavanje pre­jela Valentina Pezdir s soavtorjema. Plenarna predavanja Štiri plenarna predavanja so povezovala rdeco nit letošnjega kongresa, temo »Geologija in druž­ba«, s katero smo opozarjali na vlogo in pomen geologije in geološkega profesionalizma za druž­bo in njen razvoj. Dr. Slavko Šolar, generalni se­kretar Evropskega združenja geoloških zavodov (EuroGeoSurveys), je o tem govoril v predavanju z naslovom Interakcija med znanstveniki/stro­kovnjaki in družbo: neizkorišcene priložnosti za vse? (sl. 1), dr. Vitor Correia, predsednik Evropske zveze geologov (European Federation of Geologi-sts), v predavanju Družbeni izzivi XXI. stoletja: geologija na piedestalu (sl. 2), dr. Ruth Allington, predsednica Delovne skupine IUGS za profesio­nalizem v geoznanosti (IUGS Task Group on Glo­bal Geoscience Professionalism), pa v predavanju z naslovom Brisanje meja med znanostjo in stro­ko – obveza družbeno odgovorne in koristne ge­oznanosti (sl. 3). V zadnjem plenarnem predava­nju z naslovom Geoenergetski viri Slovenije je dr. Miloš Markic predstavil prispevek širše skupine, ki se na Geološkem zavodu Slovenije ukvarja s to, za družbo zelo aktualno tematiko (sl. 4). Okrogla miza in predstavitev portala eGeologija Osrednji dogodek v okviru kongresa je bila okrogla miza z naslovom Ali je Slovenija prip­ravljena na uporabo geološkega znanja pri svo­jem razvoju? Na njej smo 4. 10. 2018 soocili razlicne poglede in izkušnje predstavnikov ge­oznanosti in uporabnikov geoloških podatkov glede vloge in pomena zbiranja, interpretiranja in javne dostopnosti geoloških podatkov za ra­zvoj družbe. V razpravi, ki jo je povezoval Igor E. Bergant, so sodelovali (sl. 5 z desne proti levi): mag. Joško Knez, Agencija RS za okolje (ARSO); Tomaž Prohinar, Direkcija za vode, MOP; Ervin Vivoda, Sektor za zmanjševanje posledic narav­nih nesrec, MOP; dr. Leopold Vrankar, Direkto­rat za energijo, MZI; dr. Tomaž Žagar, Služba za nacrtovanje in nadzor v GEN energija; An­drej Locniškar, DRI upravljanje investicij; dr. Mihael Brencic, Naravoslovnotehniška fakulteta UL in dr. Miloš Bavec, GeoZS. Cilj okrogle mize je bil, da bi mnenja razpravljavcev spodbudila snovalce politik k ucinkovitejšemu prenosu zna­nja in kompetenc slovenske geoznanosti v pra­ kso za potrebe državnih in lokalnih organov in gospodarskih subjektov. V skladu s tem ciljem so sodelavci Geološkega informacijskega centra GeoZS pred okroglo mizo predstavili spletni portal eGeologija, ki je razvit za namene zbira­nja, urejanja in javne dostopnosti podatkov o ge­osferi. Portal eGeologija je bilo možno tudi pre­izkusiti ves cas kongresa v hotelski avli (sl. 6). Sl. 5. Okrogla miza Ali je Slovenija pripravljena na uporabo geološkega znanja pri svojem razvoju? Sl. 2. Dr. Vitor Correia, predsednik Evropske zveze geologov Sl. 3. Dr. Ruth Allington, predsednica Delovne skupine (European Federation of Geologists) IUGS za profesionalizem v geoznanosti (IUGS Task Group on Global Geoscience Professionalism) Sl. 4. Dr. Miloš Markic, Geološki zavod Slovenije Sl. 6. Demonstracija spletnega portala eGeologija Sl. 7. Udeleženci ekskurzije E-1 na bloku Termoelektrarne Sl. 8. Razlaga na ekskurziji E-2 Šoštanj Sl. 9. Udeleženci ekskurzije E-3 ob profilu Velunja na prostem Ekskurzije Tridnevni kongres so sklenile tri celodnevne kongresne ekskurzije in ena tridnevna pokongre­sna ekskurzija. Ekskurzija E-1: Velenjski lignit – geološka edinstvenost in njegova vloga v ener­getiki Slovenije, je tri locene skupine vodila v aktivni del Premogovnika Velenje (jamo Pesje), Muzeja premogovništva Slovenije in Termoelek­ trarno Šoštanj (sl. 7), skupna pa sta bila uvoda predstavitev na sedežu Premogovnika in ogled obmocij z vidnimi posledicami rudarjenja in ob­mocij sanacije. Inženirsko-geološka ekskurzija E-2: Nacrtovanje trase 3. razvojne osi in geološko pogojeni dejavniki tveganja pri umešcanju pro­metnic v prostor je potekala po trasi nacrtovane­ga severnega odseka 3. razvojne osi, od prikljucka Velenje jug do Šentruperta (sl. 8). Stratigrafsko­-sedimentološko-tektonska ekskurzija E-3: Geo­loški razvoj kenozojskih sedimentacijskih baze­ nov v širši okolici Velenja je potekala na obmocjih oligocenskega Smrekovškega bazena, preko Peri­adriatske prelomne cone do Slovenjgraškega mio­censkega bazena in Velenjskega pliokvartarnega bazena (sl. 9). Pokongresna ekskurzija je podrobneje opisana v locenem prispevku v tej izdaji. Obkongresne dejavnosti in dogodki Eden od pomembnih ciljev 5. slovenskega ge­ološkega kongresa je bil tudi ta, da geologijo kot znanost in stroko predstavimo najširši družbi. V ta namen je bila organizirana vrsta obkongresnih aktivnosti in dogodkov. Organizatorja kongresa sta razpisala fotografski natecaj Geoznanost za družbo, na katerem je sodelovalo 15 avtorjev, ki so poslali skupaj 41 fotografij. Ocenjevalna ko­misija je med njimi izbrala 12 fotografij. Zmago­valne fotografije natecaja in fotografije strokov­njakov Geološkega zavoda Slovenije, ki tematsko dopolnjujejo predstavitev razlicnih vej geoznano­sti in podrocij njihovih raziskav, bodo do aprila 2019 razstavljene v velenjski Galeriji na prostem (sl. 10). Tudi razstava Litosfera, ki jo je v sodelovanju z Muzejem Velenje pripravil Oddelek za geologijo NTF in bo na Velenjskem gradu razstavljena vse do oktobra 2019, je imela podoben cilj. Na razsta­vljenih vzorcih slovenskih kamnin iz študijskih zbirk Oddelka je predstavljeno, kako geologi be­remo zgodovino Zemlje, procesov, ki jo oblikujejo in zgodovino življenja na njej. Med najpomembnejšimi ciljnimi skupinami so bili ucenci in dijaki osnovnih in srednjih šol. Za­nje smo v okviru evropskega projekta RM@Scho­ols3.0 – Raw Matters Ambassadors at Schools 3.0 v sodelovanju z Muzejem premogovništva Slove­nije pripravili delavnico o mineralnih surovinah, v sodelovanju z Visoko šolo za varstvo okolja v Velenju pa je Skupina za popularizacijo geologi­je Slovenskega geološkega društva organizirala Dan geologije z geološkimi delavnicami. Na de­lavnice se je prijavilo skupaj kar 150 ucencev in dijakov (sl. 11). Ob tem smo z organizacijo GeoTEKa okrog Škalskega jezera, tradicionalne akcije Slovenske­ga geološkega društva, poskrbeli tudi za geološko obarvano rekreacijo. Kongresna gradiva Vse podrobnejše informacije o 5. slovenskem geološkem kongresu in obkongresnih dogodkih najdete na kongresni spletni strani www.geo-zs. si/5SGK. Tam so objavljene tudi elektronske iz­daje vseh tiskanih kongresnih gradiv, video po­snetki okrogle mize in dveh plenarnih predavanj, rezultati natecajev in fotografije. Zahvala Vsem sodelujocim inštitucijam in posamezni­kom, ki so na kakršen koli nacin pripomogli k uspešni izvedbi kongresa, se v imenu organiza­cijskega odbora najlepše zahvaljujeva. Zahvalju­jeva se tudi vsem sponzorjem in donatorjem, ki so z denarnimi ali materialnimi prispevki omo­gocili izvedbo kongresa. To so: GEN energija, d.o.o.; Alpina, tovarna obutve; Atlantic Grupa; Dana, proizvodnja in prodaja pijac; Energetika Ljubljana; Fido; Gdi Gisdata; Geobrugg AG Swi­tzerland; Geokop; Gradbeni inštitut ZRMK; Ni­kon Slovenija; Ocean Orchids; Petrol Geoterm; Pomgrad; Radenska; Skupnosti znanja in inovacij EIT RawMaterials; Šcurek; Tektonik pivovarna in Termit. Short report on: Post-congress field trip of the 5th Slovenian Geological Congress, October 6th-8th 2018: Geology, hydrogeology and geothermy of NE Slovenia and N Croatia Nina RMAN Geološki zavod Slovenije, Dimiceva ul. 14, SI-1000 Ljubljana; e-mail: nina.rman@geo-zs.si The 5th Slovenian Geological Congress was a great opportunity to promote also international exchange of experience. One of the reasons that 21 researchers in the fields of hydrogeology and geothermal energy from nine countries (Slovenia, Belgium, Croatia, Hugary, New Zealand, Poland, Slovakia, Switzerland and USA) spent an intere­sting prolonged weekend together, visiting sites in Slovenia and Croatia, was also the patronage of the Commission on Mineral and Thermal Water of the International Association of Hydrogeologi­sts (CMTW-IAH). The Commission on Mineral and Thermal Wa­ter is one of the two the oldest commissions of IAH, being established in August 1968 in Pra­gue, Czechoslovakia, during the 23rd session of the International Geological Congress (IGC). The objective of the Commission is to bring together scientists, engineers and other professionals dea­ling with mineral and thermal waters, and is open also to young beginners. The traditional CMTW­-IAH annual meetings are educational, with lots of scientific and technical knowledge exchange regarding also the host country of the meeting. In 2018, the annual meeting was organised during the presented post-congress field trip, however, many commission members contributed already to the scientific sessions of the 5th Slovenian Ge­ological Congress with posters and presentations. The Commission is honoured to have among its members internationally recognized professio­nals, we may mention only some: the ambassa­ dor professor Jan Dowgiallo, professor Ladislaus Rybach, and dr. Jim LaMoreaux, the actual Cha­ irman. More about the history of the CMTW-IAH can be found in the article of Dowgiallo (2013: Envir. Earth Sci. 70: 2923-2928). On Saturday, we have learned about geo­logy and hydrogeology along the Celje-Lenart highway, visited very promising but now closed geother mal well Be-2 in Benedikt in Slovenske go-rice, tasted the mineral water of Ivanjševska sla­tina, listened to the natural CO2 seeps at mofette Strmec, visited the bottling company Radenska d.o.o., heard about the shallow and deep geother­mal energy use as well as coal and hydrocarbon exploration in NE Slovenia, visited the exhibition on 75 years of hydrocarbon exploitation at Lenda­va, and visited the geothermal doublet in Lenda­va. On Sunday, we stared at a natural oil spring in Peklenica, walked on the Quaternary sands “Ðurdevacki peski” and discussed the local drin­king water supply, had a most interesting visit to a brand new nearly-opened geothermal power plant in Velika Ciglena, and listened to the geo­logical evolution of the Croatian Zagorje Region in Stubicke Toplice. On Monday, we have learned about the bathing and heating technology in the AQUAE VIVAE Waterpark in Krapinske Toplice, visited the exhibition in the Krapina Neanderthal Museum, and tasted the natural mineral waters in Rogaška Slatina. Fig. 1. Mofette Strmec (photo: D. Rajver). Fig. 2. Natural oil spring in Peklenica (photo: N. Rman). Fig. 3. Wells in geothermal power plant in Velika Ciglena (photo: L. Serianz). Evaluation showed that the most interesting topics to the participants were: geothermal power plant in Velika Ciglena, chemistry, isotopic data and hydrogeological information, presentation of Mg rich natural mineral waters and natural oil spring in Peklenica. In future, more informati­on is wanted also on the utilization of geother­mal and mineral water in Slovenia in relation to Europe, operation of various geothermal systems for heat production in neighbouring countries, shallow geothermal heating and cooling practice, mitigation of scaling and environmental effects of geothermal fluid production and, of course, strategy and perspective of geothermal energy in the region. The journey was positioned in the pilot area of the project DARLINGe (http:// www.interreg-danube.eu/approved-projects/dar­linge), and we hope that with this international knowledge exchange we will help to support en­hanced sustainable use of geothermal energy in this region with really high geothermal potential. As we see it, the interest in further development among experts is promising. Organization of the field trip was the result of collaboration of several institutions and their representatives, dr. Nina Rman, dr. Tamara Mar­kovic and assoc. prof. dr. Mihael Brencic as repre­sentatives from the Slovenian Geological Society, the Geological Survey of Slovenia, the Faculty of Natural Sciences and Engineering of the Uni­versity of Ljubljana, the Slovenian Committee of the International Association of Hydrogeologists, the Croatian Geological Society and the Croatian Geological Survey. Beside them, we also thank to sponsors who supported the field trip in various ways: Atlantic Grupa d.d., Dana d.o.o., Krapina Neanderthal museum, Petrol Geoterm d.o.o. and Radenska d.o.o. Posvetovanje »Vloga in pomen geologije v formalnem izobraževanju«, Ljubljana 5. 12. 2019, Oddelek za geologijo NTF Petra ŽVAB ROŽIC Naravoslovnotehniška fakulteta, Oddelek za geologijo, Aškerceva 12, SI-1000 Ljubljana Slovensko geološko društvo, Dimiceva ul. 14, SI-1000 Ljubljana; e-mail: petra.zvab@ntf.uni-lj.si V okviru tedna Univerze v Ljubljani je v sre­do, 5.12.2018 na Oddelku za geologijo Naravo­slovnotehniške fakultete potekalo posvetovanje z naslovom »Vloga in pomen geologije v formalnem izobraževanju«. Dogodek sta organizirala Oddel­ka za geologijo (NTF, UL) in Slovensko geološko društvo (SGD). Posvetovanje je bilo namenjeno razpravi o tem, kakšna je vloga geologije pri izo­braževanju na stopnji predšolske vzgoje, osnovne in srednje šole, predstavljen pa je bil tudi pomen geologije v srednješolskem in visokošolskem iz­obraževanju. Predstavljeni so bili rezultati dela v okviru razlicnih projektov in v zadnjih letih tudi Skupine za popularizacijo geologije, ki se je v okviru Slovenskega geološkega društva z letom 2018 formirala v Sekcijo za popularizacijo geolo­gije. Med predstavitvami je potekala odprta raz­prava vseh sodelujocih. Uvodni pozdrav so izrek­li namestnik predstojnice Oddelka za geologijo izr. prof. dr. Mihael Brencic in v. d. predsednika Slovenskega geološkega društva dr. Matevž No­vak. Dogodek je vodila in povezovala predsedni­ca Sekcije za popularizacijo geologije doc. dr. Pe­tra Žvab Rožic z Oddelka za geologijo. V prvi predstavitvi se je mag. Mojca Bedjanic (Zavod RS za varstvo narave), osredotocila na vkljucevanje vsebin geologije in varstva geološke naravne dedišcine v vrtce in 1. triado OŠ, ki je rezultat dolgoletnega izobraževanja na Zavodu RS za varstvo narave in UNESCO Globalnega Geoparka Karavanke. Predstavila je, na kakšen nacin se geološki cilji pojavljajo v vrtcih in 1. tri­adi OŠ. Ti so v kurikulumu za vrtce na geolo­gijo navezani posredno, skozi spoznavanje mate­rialov in pokrajine, v ucnih nacrtih za 1. triado OŠ pa posredno vezani na geološko tematiko pri predmetu Spoznavanje okolja skozi spoznavanje snovi. Opozorila je, da je vkljucevanje vsebin ge­ologije v tem obdobju izobraževanja v veliki meri odvisno od vzgojitelja oz. ucitelja. Da bi le te spodbudili k vkljucevanju geoloških vsebin v nji­hove programe, v Geoparku Karavanke že nekaj let pripravljajo in aktivno izvajajo Geo-projektne dneve v okviru projekta “Zabavno, poucno, nic mucno”, ki so primer dobre prakse vkljuceva­nja geoloških vsebin v formalno izobraževanje. Njihov namen je spodbujati drugacen pristop k vzgoji in poucevanju, aktiven odnos do vsebin s podrocja geologije in dvigovanje ustvarjalnosti. Sledilo je predavanje doc. dr. Tomislava Popi­ta (Oddelek za geologijo NTF), ki je predstavil del rezultatov projekta ESTEAM Erazmus+. Eden od ciljev projekta je izdelati mobilno aplikacijo za poucevanje naravoslovnih vsebin v osnovnih šo­lah (ciljna skupina 3. triada). Predstavil je rezul­tate analize naravoslovnih vsebin nacionalnih ucnih nacrtov, izpostavil je pomen metodologij poucevanja naravoslovnih vsebin in prikazal re­zultate vprašalnikov, ki so jih v okviru projek­ta pripravili za ucence ter za obstojece in bodo­ce ucitelje. Rezultati nacionalnih ucnih nacrtov kažejo premajhen obseg pedagoških ur, ki so na razpolago za geološke vsebine. Rezultati vprašal­nikov so pokazali, da se ucenci radi ucijo s po­mocjo eksperimentov, z uporabo IKT tehnologij in v naravi, kar pa se v praksi redko ali nikoli ne izvaja. Pomemben in celo zaskrbljujoc rezul­tat pa je ta, da skoraj polovica vprašanih na leto za poucevane in ucenje naravoslovnih vsebin na prostem preživi le od enega do dveh dni. Rezultate natancnih analiz trenutno veljavnih ucnih nacrtov in vsebin ucbenikov za osnovne in srednje šole je predstavil Rok Brajkovic (Geolo­ški zavod Slovenije). Osredotocil se je predvsem na taksonomsko nadgradnjo geoloških vsebin, in ali le te ustrezajo zahtevanim stopnjam ucnih ci­ljev, izpostavil je medpredmetno povezanost vse­bin, ki je eden od pomembnih faktorjev za dvig trajnosti znanja, na primerih pa je predstavil nekaj vsebinskih nepravilnosti in pomanjkljivo­sti, ki se pojavljajo v obstojecih ucbenikih. Ucni cilji in vsebine se vecinoma smiselno nadgraju­jejo, vendar ostajajo predvsem na prvih treh ta­ksonomskih stopnjah (poznavanje, razumevanje, uporaba). Medpredmetna povezava je precej po­manjkljiva, kar vodi v precejšnjo vsebinsko zme­do in predvsem nezmožnost povezovanja in nad­grajevanja vsebin. Poleg tega so geološke vsebine v ucbenikih strokovno pomanjkljive in nezvezne. Razvoj geološkega izobraževanja v slovenskem nacionalnem prostoru je predstavil izr. prof. dr. Mihael Brencic (Oddelek za geologijo NTF). Iz­ postavil je pomen definicije geologije pri razu­mevanju razvoja geološkega izobraževanja ter vpliv družbeno ekonomskih in politicnih razmer v poucevanju geologije. Pregled geološkega izo­braževanja je zacel z razvojem znanstvene geolo­gije v 18. stoletju in pomenom idrijskega rudnika v tistem casu. Geologija je bila v visokošolskem izobraževanju prisotna že pred ustanovitvijo Univerze v Ljubljani, v okviru drugih podrocij poucevanja ter v strokovnih revijah, pomemben del izobraževalnih vsebin pa je bila vse od za­cetka ustanovitve Univerze. V srednješolskem izobraževanju se je poucevanje geologije pojavilo z uvedbo realnih gimnazij sredi 19. stoletja, kar je privedlo tudi do prvih ucbenikov s podrocja geologije v slovenskem jeziku. Geologija se kot samostojni predmet v srednjih šolah ne poucuje od konca 80. let 20 stoletja, kar pomeni, da je bila vec kot 140 let del srednješolskega poucevanja. Dejstvo je, da geologija v sekundarnem izobraže­vanju nikoli ni bila v slabši poziciji kot je danes. Razprava v okviru posveta je prispevala po­membna dejstva tudi s strani udeležencev, ki bodo poleg vseh prikazanih rezultatov predsta­vljala uporabne dopolnitve za nacrtovanje dela in izzivov v bodoce. Predvsem bi si želeli vkljuceva­nja geologov v morebitno prenovo ucnih nacrtov, sodelovanja pri strokovnih recenzijah šolskih ucbenikov ter povezovanja in vkljucevanja geo­logov v poucevanje bodocih uciteljev, ki geološke vsebine na osnovnih in srednjih šolah poucujejo. Dolgorocni cilj pa je ponovna uvedba samostoj­nega predmeta Geologija v srednje šole. Navodila avtorjem GEOLOGIJA objavlja znanstvene in strokovne clanke s podrocja geologije in sorodnih ved. Revija izhaja dvakrat letno. Clanke recenzirajo domaci in tuji strokovnjaki z obravnavanega podrocja. Ob oddaji clankov avtorji predlagajo tri recenzente, uredništvo si pridržuje pravico do izbire recenzentov po lastni presoji. Avtorji morajo clanek popraviti v skladu z recenzentskimi pripombami ali utemeljiti zakaj se z njimi ne strinjajo. Avtorstvo: Za izvirnost podatkov, predvsem pa mnenj, idej, sklepov in citirano literaturo so odgovorni avtorji. Z objavo v GEOLOGIJI se tudi obvežejo, da ne bodo drugje objavili prispevka z isto vsebino. Avtorji z objavo prispevka v GEOLOGIJI potrjujejo, da se strinjajo, da je njihov prispevek odprto dostopen z izbrano licenco CC-BY. Jezik: Clanki naj bodo napisani v angleškem, izjemoma v slovenskem jeziku, vsi pa morajo imeti slovenski in angleški izvlecek. Za prevod poskrbijo avtorji prispevkov sami. Vrste prispevkov: Izvirni znanstveni clanek Izvirni znanstveni clanek je prva objava originalnih razisko­valnih rezultatov v takšni obliki, da se raziskava lahko ponovi, ugotovitve pa preverijo. Praviloma je organiziran po shemi IMRAD (Introduction, Methods, Results, And Discussion). Pregledni znanstveni clanek Pregledni znanstveni clanek je pregled najnovejših del o dolocenem predmetnem podrocju, del posameznega razisko­ valca ali skupine raziskovalcev z namenom povzemati, analizirati, evalvirati ali sintetizirati informacije, ki so že bile publicirane. Prinaša nove sinteze, ki vkljucujejo tudi rezultate lastnega raziskovanja avtorja. Strokovni clanek Strokovni clanek je predstavitev že znanega, s poudarkom na uporabnosti rezultatov izvirnih raziskav in širjenju znanja. Diskusija in polemika Prispevek, v katerem avtor ocenjuje ali komentira neko delo, objavljeno v GEOLOGIJI, ali z avtorjem strokovno polemizira. Recenzija, prikaz knjige Prispevek, v katerem avtor predstavlja vsebino nove knjige. Oblika prispevka: Besedilo pripravite v urejevalniku Micro- soft Word. Prispevki naj praviloma ne bodo daljši od 20 strani formata A4, v kar so vštete tudi slike, tabele in table. Le v izjemnih primerih je možno, ob predhodnem dogovoru z uredništvom, tiskati tudi daljše prispevke. Clanek oddajte uredništvu vkljucno z vsemi slikami, tabelami in tablami v elektronski obliki po naslednjem sistemu: -Naslov clanka (do 12 besed) - Avtorji (ime in priimek, poštni in elektronski naslov) -Kljucne besede (do 7 besed) -Izvlecek (do 300 besed) -Besedilo -Literatura - Podnaslovi slik in tabel -Tabele, Slike, Table Citiranje: V literaturi naj avtorji prispevkov praviloma upoštevajo le objavljene vire. Porocila in rokopise naj navajajo le v izjemnih primerih, z navedbo kje so shranjeni. V seznamu literature naj bodo navedena samo v clanku omenjena dela. Citirana dela, ki imajo DOI identifikator (angl. Digital Object Identifier), morajo imeti ta identifikator izpisan na koncu citata. Za citiranje revije uporabljamo standardno okrajšavo naslova revije. Med besedilom prispevka citirajte samo avtorjev priimek, v oklepaju pa navajajte letnico izida navedenega dela in po potrebi tudi stran. Ce navajate delo dveh avtorjev, izpišite med tekstom prispevka oba priimka (npr. Plenicar & Buser, 1967), pri treh ali vec avtorjih pa napišite samo prvo ime in dodajte et al. z letnico (npr. Mlakar et al., 1992). Citiranje virov z medmrežja v primeru, kjer avtor ni poznan, zapišemo (Internet 1). V seznamu literaturo navajajte po abecednem redu avtorjev. Imena fosilov (rod in vrsta) naj bodo napisana poševno, imena višjih taksonomskih enot (družina, razred, itn.) pa normalno. Imena avtorjev taksonov naj bodo prav tako napisana normalno, npr. Clypeaster pyramidalis Michelin, Galeanella tollmanni (Kristan), Echinoidea. Primeri citiranja clanka: Mali, N., Urbanc, J. & Leis, A. 2007: Tracing of water movement through the unsaturated zone of a coarse gravel aquifer by means of dye and deuterated water. Environ. geol., 51/8: 1401–1412. https://doi.org/10.1007/s00254-006-0437-4 Plenicar, M. 1993: Apricardia pachiniana Sirna from lower part of Liburnian beds at Divaca (Triest-Komen Plateau). Geologija, 35: 65–68 Primer citirane knjige: Flügel, E. 2004: Mikrofacies of Carbonate Rocks. Springer Verlag, Berlin: 976 p. Jurkovšek, B., Toman, M., Ogorelec, B., Šribar, L., Drobne, K., Poljak, M. & Šribar, Lj. 1996: Formacijska geološka karta južnega dela Tržaško-komenske planote – Kredne in paleogenske kamnine 1: 50.000 = Geological map of the southern part of the Trieste-Komen plateau – Cretaceous and Paleogene carbonate rocks. Geološki zavod Slovenije, Ljubljana: 143 p., incl. Pls. 23, 1 geol. map. Primer citiranja poglavja iz knjige: Turnšek, D. & Drobne, K. 1998: Paleocene corals from the northern Adriatic platform. In: Hottinger, L. & Drobne, K. (eds.): Paleogene Shallow Benthos of the Tethys. Dela SAZU, IV. Razreda, 34/2: 129–154, incl. 10 Pls. Primer citiranja virov z medmrežja: Ce sta znana avtor in naslov citirane enote zapišemo: Carman, M. 2009: Priporocila lastnikom objektov, zgrajenih na nestabilnih obmocjih. Internet: http://www.geo-zs. si/UserFiles/1/File/Nasveti_lastnikom_objektov_na_ nestabilnih_tleh.pdf (17. 1. 2010) Ce avtor ni poznan zapišemo tako: Internet: http://www.geo-zs.si/ (22. 10. 2009) Ce se navaja vec enot z medmrežja, jim dodamo še številko: Internet 1: http://www.geo-zs.si/ (15. 11. 2000) Internet 2: http://www.geo-zs.si/ (10. 12. 2009) Slike, tabele in table: Slike (ilustracije in fotografije), tabele in table morajo biti zaporedno oštevilcene in oznacene kot sl. 1, sl. 2 itn., oddane v formatu TIFF, JPG, EPS ali PDF z locljivostjo 300 dpi. Le izjemoma je možno objaviti tudi barvne slike, vendar samo po predhodnem dogovoru z uredništvom. Ce avtorji oddajo barvne slike bodo te v barvah objavljene samo v spletni razlicici clanka. Pazite, da bo tudi slika tiskana v sivi tehniki berljiva. Graficni materiali naj bodo usklajeni z zrcalom revije, kar pomeni, da so široki najvec 172 mm (ena stran) ali 83 mm (pol strani, en stolpec) in visoki najvec 235 mm. Vecjih formatov od omenjenega zrcala GEOLOGIJE ne tiskamo na zgib, je pa možno, da vecje oziroma daljše slike natisnemo na dveh straneh (skupaj na levi in desni strani) z vmesnim "rezom". V besedilu prispevka morate omeniti vsako sliko po številcnem vrstnem redu. Dovoljenja za objavo slikovnega gradiva iz drugih revij, publikacij in knjig, si pridobijo avtorji sami. Ce je clanek napisan v slovenskem jeziku, mora imeti celotno besedilo, ki je na slikah in tabelah tudi v angleškem jeziku. Podnaslovi naj bodo cim krajši. Korekture: Avtorji prejmejo po elektronski pošti clanek v avtorski pregled. Popravijo lahko samo tiskarske napake. Krajši dodatki ali spremembe pri korekturah so možne samo na avtorjeve stroške. Prispevki so prosto dostopni na spletnem mestu: http://www. geologija-revija.si/ Oddaja prispevkov: Avtorje prosimo, da prispevke oddajo v elektronski obliki na naslov uredni{tva: GEOLOGIJA Geolo{ki zavod Slovenije Dimi~eva ulica 14, SI-1000 Ljubljana bernarda.bolegeo-zs.si ali urednikgeologija-revija.si Uredni{tvo Geologije Instructions for authors Scope of the journal: GEOLOGIJA publishes scientific papers which contribute to understanding of the geology of Slovenia or to general understanding of all fields of geology. Some shorter contributions on technical or conceptual issues are also welcome. Occasionally, a collection of symposia papers is also published. All submitted manuscripts are peer-reviewed. When submitting paper, authors should recommend at least three reviewers. Note that the editorial office retains the sole right to decide whether or not the suggested reviewers are used. Authors should correct their papers according to the instructions given by the reviewers. Should you disagree with any part of the reviews, please explain why. Revised manuscript will be reconsidered for publication. Author’s declaration: Submission of a paper for publication in GEOLOGIJA implies that the work described has not been published previously, that it is not under consideration for publication elsewhere and that, if accepted, it will not be published elsewhere. Authors agree that their contributions published in GEOLOGIJA are open access under the licence CC-BY. Language: Papers should be written in English or Slovene, and should have both English and Slovene abstracts. Types of papers: Original scientific paper In an original scientific paper, original research results are published for the first time and in such a form that the research can be repeated and the results checked. It should be organised according to the IMRAD scheme (Introduction, Methods, Results, And Discussion). Review scientific paper In a review scientific paper the newest published works on specific research field or works of a single researcher or a group of researchers are presented in order to summarise, analyse, evaluate or synthesise previously published information. However, it should contain new information and/or new interpretations. Professional paper Technical papers give information on research results that have already been published and emphasise their applicability. Discussion paper A discussion gives an evaluation of another paper, or parts of it, published in GEOLOGIJA or discusses its ideas. Book review This is a contribution that presents a content of a new book in the field of geology. Style guide: Submitted manuscripts should not exceed 20 pages of A4 format including figures, tables and plates. Only exceptionally and in agreement with the editorial board longer contributions can also be accepted. Manuscripts submitted to the editorial office should include figures, tables and plates in electronic format organized according to the following scheme: -Title (maximum 12 words) - Authors (full name and family name, postal address and e-mail address) - Key words (maximum 7 words) - Abstract (maximum 300 words) -Text - References - Figure and Table Captions -Tables, Figures, Plates References: References should be cited in the text as follows: (Flügel, 2004) for a single author, (Plenicar & Buser, 1967) for two authors and (Mlakar et al., 1992) for multiple authors. Pages and figures should be cited as follows: (Plenicar, 1993, p. 67) and (Plenicar, 1993, fig. 1). Anonymous internet resources should be cited as (Internet 1). Only published references should be cited. Manuscripts should be cited only in some special cases in which it also has to be stated where they are kept. Cited reference list should include only publications that are mentioned in the paper. Authors should be listed alphabetically. Journal titles should be given in a standard abbreviated form. A DOI identifier, if there is any, should be placed at the end as shown in the first case below. Taxonomic names should be in italics, while names of the authors of taxonomic names should be in normal, such as Clypeaster pyramidalis Michelin, Galeanella tollmanni (Kristan), Echinoidea. Articles should be listed as follows: Mali, N., Urbanc, J. & Leis, A. 2007: Tracing of water movement through the unsaturated zone of a coarse gravel aquifer by means of dye and deuterated water. Environ. geol., 51/8: 1401–1412. https://doi.org/10.1007/s00254-006-0437-4 Plenicar, M. 1993: Apricardia pachiniana Sirna from lower part of Liburnian beds at Divaca (Triest-Komen Plateau). Geologija, 35: 65–68. Books should be listed as follows: Flügel, E. 2004: Mikrofacies of Carbonate Rocks. Springer Verlag, Berlin: 976 p. Jurkovšek, B., Toman, M., Ogorelec, B., Šribar, L., Drobne,K., Poljak, M. & Šribar, Lj. 1996: Formacijska geološka karta južnega dela Tržaško-komenske planote – Kredne in paleogenske kamnine 1: 50.000 = Geological map of the southern part of the Trieste-Komen plateau – Cretaceous and Paleogene carbonate rocks. Geološki zavod Slovenije, Ljubljana: 143 p., incl. Pls. 23, 1 geol. map. Book chapters should be listed as follows: Turnšek, D. & Drobne, K. 1998: Paleocene corals from the northern Adriatic platform. In: Hottinger, L. & Drobne, K. (eds.): Paleogene Shallow Benthos of the Tethys. Dela SAZU, IV. Razreda, 34/2: 129–154, incl. 10 Pls. Internet sources should be listed as follows: Known author and title: Carman, M. 2009: Priporocila lastnikom objektov, zgrajenih na nestabilnih obmocjih. Internet: http://www.geo-zs. si/UserFiles/1/File/Nasveti_lastnikom_objektov_na_ nestabilnih_tleh.pdf (17. 1. 2010) Unknown authors and title: Internet: http://www.geo-zs.si/ (22.10.2009) When more than one unit from the internet are cited they should be numbered: Internet 1: http://www.geo-zs.si/ (15.11. 2000) Internet 2: http://www.geo-zs.si/ (10.12. 2009) Figures, tables and plates: Figures (illustrations and photographs), tables and plates should be numbered consecutively and marked as Fig. 1, Fig. 2 etc., and saved as TIFF, JPG, EPS or PDF files and submitted at 300 dpi. Colour pictures will be published only on the basis of previous agreement with the editorial office. If, together with the article, you submit colour figures then these figures will appear in colour only in the Website version of the article. Be careful that the grey scale printed version is also readable. Graphic materials should be adapted to the journal’s format. They should be up to 172 mm (one page) or 83 mm wide (half page, one column), and up to 235 mm high. Larger formats can only be printed as a double-sided illustration (left and right) with a cut in the middle. All graphic materials should be referred to in the text and numbered in the sequence in which they are cited. The approval for using illustrations previously published in other journals or books should be obtained by each author. When a paper is written in Slovene it has to have the entire text which accompanies illustrations and tables written both in Slovene and English. Figure and table captions should be kept as short as possible. Proofs: Proofs (in pdf format) will be sent by e-mail to the corresponding author. Corrections are made by the authors. They should correct only typographical errors. Short additions and changes are possible, but they will be charged to the authors. GEOLOGIJA is an open access journal; all pdfs can be downloaded from the website: http://www.geologija-revija.si/ en/ Submission: Authors should submit their papers in electronic form to the address of the GEOLOGIJA editorial office: GEOLOGIJA Geological Survey of Slovenia Dimi~eva ulica 14, SI-1000 Ljubljana, Slovenia bernarda.bolegeo-zs.si or urednikgeologija-revija.si The Editorial Office GEOLOGIJA št.: 61/2, 2018 www.geologija-revija.si Bavec, M. 131 Manj sivine (uvodnik) Car, J. 133 Geostructural mapping of karstified limestones Kercmar, J. 163 Nahajališca zemeljskega plina na naftno-plinskem polju Petišovci Peternel, T., Jež, J., Milanic, B., Markelj, A. & Jemec Auflic, M. 177 Engineering-geological conditions of landslides above the settlement of Koroška Bela (NW Slovenia) Janža, M., Serianz, L., Šram, D. & Klasinc, M. 191 Hydrogeological investigation of landslides Urbas and Cikla above the settlement of Koroška Bela (NW Slovenia) Brencic, M. 205 Comparison of the fully penetrating well drawdown in leaky aquifers between finite and infinite radius of influence under steady-state pumping conditions Uhan, J. & Andjelov, M. 215 Primerjava rezultatov modeliranja vsebnosti nitrata v vodi pod koreninskim obmocjem tal v lokalnem in regionalnem merilu Brencic, M. 229 Korespondenca med Vasilijem Vasilijevicem Nikitinom in Vladimirjem Ivanovicem Vernadskim Brajkovic, R., Bedjanic, M., Malenšek Andolšek, N., Rman, N., Novak, M., Šušmelj, K. & Žvab Rožic, P. 239 Sistematicen pregled geoloških ucnih ciljev in ucbeniških vsebin v osnovnih šolah in v splošnih gimnazijah Peulic, K., Novak, M. & Vrabec, Mi. 253 Provenance and characteristics of the pavement stone from the courtyard of the Ljubljana Castle ISSN 0016-7789