ISSN 1408-7073 RMZ - MATERIALS AND GEOENVIRONMENT PERIODICAL FOR MINING, METALLURGY AND GEOLOGY RMZ - MATERIALI IN GEOOKOLJE REVIJA ZA RUDARSTVO, METALURGIJO IN GEOLOGIJO RMZ-M&G, Vol. 54, No. 2 pp. 151-302 (2007) Ljubljana, October 2007 Historical Review More than 80 years have passed since in 1919 the University Ljubljana in Slovenia was founded. Technical fields were joint in the School of Engineering that included the Geologic and Mining Division while the Metallurgy Division was established in 1939 only. Today the Departments of Geology, Mining and Geotechnology, Materials and Metallurgy are part of the Faculty of Natural Sciences and Engineering, University of Ljubljana. Before War II the members of the Mining Section together with the Association of Yugoslav Mining and Metallurgy Engineers began to publish the summaries of their research and studies in their technical periodical Rudarski zbornik (Mining Proceedings). Three volumes of Rudarski zbornik (1937, 1938 and 1939) were published. The War interrupted the publication and not until 1952 the first number of the new journal Rudarsko-metalurški zbornik - RMZ (Mining and Metallurgy Quarterly) has been published by the Division of Mining and Metallurgy, University of Ljubljana. Later the journal has been regularly published quarterly by the Departments of Geology, Mining and Geotechnology, Materials and Metallurgy, and the Institute for Mining, Geotech-nology and Environment. On the meeting of the Advisory and the Editorial Board on May 22nd 1998 Rudarsko-metalurški zbornik has been renamed into "RMZ - Materials and Geoenvironment (RMZ -Materiali in Geookolje)" or shortly RMZ - M&G. RMZ - M&G is managed by an international advisory and editorial board and is exchanged with other world-known periodicals. All the papers are reviewed by the corresponding professionals and experts. RMZ - M&G is the only scientific and professional periodical in Slovenia, which is published in the same form nearly 50 years. It incorporates the scientific and professional topics in geology, mining, and geotechnology, in materials and in metallurgy. The wide range of topics inside the geosciences are welcome to be published in the RMZ -Materials and Geoenvironment. Research results in geology, hydrogeology, mining, geotechnology, materials, metallurgy, natural and antropogenic pollution of environment, biogeochemistry are proposed fields of work which the journal will handle. RMZ - M&G is co-issued and co-financed by the Faculty of Natural Sciences and Engineering Ljubljana, and the Institute for Mining, Geotechnology and Environment Ljubljana. In addition it is financially supported also by the Ministry of Higher Education, Science and Technology of Republic of Slovenia. Editor in chief Table of Contents - Kazalo Characterization of titanium and stainless steel medical implants surfaces Karakterizacija površin medicinskih vsadkov iz titana in nerjavnih jekel Bombač, D., Brojan, M., Krkovič, M., Turk, R., Zalar, A......................................... 151 Hot forming of Zn and ZnCuTi, ZnPb alloys Toplo preoblikovanje Zn in zlitin ZnCuTi ter ZnPb Fajfar, P., Turk, R., Breskvar, B., Terčelj, M............................................................. 165 Varjenje močno legiranih jekel z oplaščenimi elektrodami Welding of high-alloy steels with covered electrodes Kejžar, R., Kosec, L., Kejžar U.................................................................................... 179 Določitev meje T/J z analizo stabilnih izotopov 513C in 518O (Krim, Slovenija) Determination of T/J boundary by 513C and 518O stable isotope analysis (Krim Mountain, Slovenia) Miler, M., Pavšič, J., Dolenec, M................................................................................. 189 Foraminiferal suborder Robertinina from the Badenian of Kozjansko (Eastern Slovenia) Foraminiferni podred Robertinina iz badenija na Kozjanskem (vzhodna Slovenija) Oblak, K........................................................................................................................ 203 Geological characteristics of the terrain along Vc corridor between Sava river and Sarajevo town Bašagić, M., Škripić, N., Skopljak, F. ........................................................................... 217 Environmental protection and investment costs as factors of road placement Okolje in investicijski stroški kot dejavnika za umeščanje cestne trase v prostor Kočevar, H., Šetinc, M................................................................................................. 223 Designing a national groundwater quantity monitoring network on groundwater bodies with alluvial aquifers in Slovenia Načrtovanje državne mreže za spremljanje količin podzemne vode na vodnih telesih podzemne vode z aluvialnimi vodonosniki SouvENT, P., Mikulič, Z., Andjelov, M., Savić, V. ......................................................... 235 A contribution to construction monitoring with simultaneous application of various types of observations Prispevek k spremljanju objektov s simultanimi meritvami različnih tipov Vulić, M., Üranjek, G................................................................................................... 247 Distance reduction with the use of UDF and Mathematica Redukcija dolžin z uporabo MS Excel-ovih lastnih funkcij in programa Mathematica Vulić, M., Brecelj, U.................................................................................................... 265 Predstavitev Oddelka za materiale in metalurgijo Naravoslovnotehniške fakultete na sejmu GIFA, METEC, THERM PROCESS in NEWCAST 2007 Kores, S., Petrič, M., Vončina, M................................................................................................................................................................287 Author s Index, Vol. 54, No. 2 ................................................................................................................................................................291 Instructions to Authors ........................................................................................................................................................................................292 Template ............................................................................................................................................................................................................................................295 No. of indexing of RMZ-M&G in singular Databases Število indeksiranih člankov iz RMZ-M&G v posameznih bazah ................................................................302 Characterization of titanium and stainless steel medical implants surfaces Karakterizacija površin medicinskih vsadkov iz titana in nerjavnih jekel David Bombač 1, Miha Brojan2, Matija Krkovič3, Radomir Turk 1, Anton Zalar1,4 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva cesta 12, SI-1000 Ljubljana, Slovenia; E-mail: david.bombac@ntf.uni-lj.si, rado.turk@ntf.uni-lj.si 2 University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva cesta 6, SI-1000 Ljubljana, Slovenia; E-mail: miha.brojan@fs.uni-lj.si 3 University Medical Center, Zaloška cesta 7, SI-1525 Ljubljana, Slovenia; E-mail: matija.krkovic@kclj.si 4 Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; E-mail: anton.zalar@ijs.si Received: March 25, 2007 Accepted: September 28, 2007 Abstract: Medical implants made from titanium and stainless steel have been used widely and successfully for various types of trauma and orthopaedic reconstructions. It is believed that oxide films covering implant surfaces are of crucial importance for biocompatibility and successful osseointegra-tion. The aim of this study is to investigate the surfaces of new and used commercial medical implants made from titanium and stainless steel. The surfaces were studied by Auger electron spectroscopy (AES) and Atomic force microscopy (AFM). Izvleček: Medicinski vsadki narejeni iz titana in nedavnega jekla so uspešno uporabljani v kirurški praksi pri rekonstrukcijah v travmatologiji in ortopediji. Splošno prepričanje je, da so oksidne plasti, ki prekrivajo površine, bistvenega pomena pri biokompatibilnosti in uspešni oseointegraciji. Cilj te študije je preiskava površin komercialnih novih in že uporabljenih medicinskih vsadkov narejenih iz titana in nerjavnih jekel. Površine so bile preiskane z Augerjevo elektronsko spektroskopijo (AES) in mikroskopijo na atomsko silo (AFM). Key words: medical implants, AES, depth profiling, AFM, roughness Ključne besede: medicinski vsadki, AES, profilna analiza, AFM, hrapavost Introduction Implants used in medicine for bone osteosynthesis have to satisfy functional demands defined by the working environment of human body. Ideally, they should have biomechanical properties comparable to those of autogenous tissues without any adverse effects. The principal requirements are corrosion resistance, biocompat-ibility, biofunctionality, bioadhesion, etc. Geometry, roughness and other characteristics of the implant surface also importantly influence the surface-tissue interaction, which is considered to be dynamic. In the first few seconds after the contact has been made, there are only water, dissolved ions, and free biomolecules in the closest proximity of the surface, but no cells. The composition of the body liquid changes continuously as inflammatory and healing processes precede, causing changes in the composition of the adsorbed layer of biomolecules on the implant surface until it is balanced. Cells and tissues eventually contact the surface and, depending on the nature of the adsorbed layer, they respond in specific ways that may further modify the adsorbed biomolecules[1]. Currently commercially pure (CP-Ti), titanium alloy TiAl6V4 and stainless steel AISI 316L are the most popular alloys used for the trauma and orthopaedic medical implants and are normally covered with a thin protective film, which largely determines the surface properties of an implant. On stainless steel a layer of the surface oxide is formed either during manufacturing or intentionally passivated in various media. Passivation is the spontaneous formation of a surface film on a metal which inhibits further corrosion. A metal is passive when it behaves nobler than it is in a given solution as a result of the protective surface film, usually an oxide. As the name indicates, the metal is then said to be passive to corrosion. Passivation of AISI 316L steel can be performed either thermally, electro-chemically, or in nitric acid. Very good corrosion resistance of medical grade stainless steel is derived from the protective layer of chromium oxide type Cr2O3 that forms on the surface. If surface is damaged, e.g. scratched the oxide layer reforms almost instantly and can be referred to as "self-healing"[2]. This surface oxide provides the ultimate interface with tissue after implantation and behaves differently compared to bare metallic surface. The corrosion process is responsible for cell toxicity and stimulates fibroblast growth, protein, and platelet adhesion. Metallic implants can interact with living tissue in 3 ways: (1) by electron exchange - redox reaction, (2) by proton exchange - hydrolysis, and (3) by complex formation - metal ion-organic molecule binding. The behaviour of stainless steel is dominated by its nickel component, which induces all 3 reactions, whereas none have been observed with titanium[3]. Studies by other authors reported the surface oxide on commercially available titanium implant systems, consisted mainly of TiO2, and the oxide structure was found to be noncrystalline[4-6]. This thin oxide film, naturally formed on a titanium substrate, is presumably responsible for the excellent biocompatibility of titanium implants due to a low level of electronic conductivity[7], a high corrosion resistance and a thermo-dynamically stable state at physiological pH values[8],[9]. The primary goal of this study was to investigate the difference of the surfaces chemical and physical properties on the unused and the in-vitro implanted medical device by using atomic force microscopy (AFM) to study the surface morphology and Auger electron spectroscopy (AES) to analyze the chemical composition of surface oxide layers. Experimental procedure Osteosynthetic medical implants for this study have been provided by the University Medical Centre Ljubljana. Obtained os-teosyntetic material have been commercial products: compression plates LCP Locking Compression Plates, screw and Phi-los plate system manufactured by Synthes GmbH. Titanium based samples have been coated with TiN based hard coating with two different colours (exact preparation technique of surface coatings is unknown due to the commercial nature of obtained osteosyntetic material). Details of the implants investigated are shown in Table 1. Surface analyses were performed on the central portions of the external surfaces of implants made from AISI 316L stainless steel and Ti-based alloys. The plate shaped implants were cut in dimensions of approximately 1*1 cm and mounted into the spectrometer. Chemical composition of the samples surfaces were characterized with AES instrument SAM, PHI Model 545A, manufactured by Physical Electronics Industries Inc. The argon pressure in the chamber during depth profiling was about 10-5 Pa and the base pressure was about 1.1*10-9 Pa. A static primary electron beam of 3 keV, 1 ^A and a diameter of approximately 40 ^m were used. The samples were sputtered using two symmetrically inclined Perkin-Elmer- PHI Mod. 04-191 ion guns. The ion incidence angle was about 47 ° with respect to the normal of the sample surface. The samples were sputtered with 1 keV Ar+ ion beams, rastered on area of 5*5 mm. AES depth profiles of the samples were obtained by continuous ion sputtering. The sputtering rate determined on a Cr/Ni multilayer reference sample was about 4 nm/min. The sputter rate is dependent on a number of factors such as instrumental factors (adsorption from residual gas atmosphere, impurities in ion beam, etc.), sample characteristics (original surface roughness, compounds, second phases, etc.) and radiation induced effects (primary atom implantation, atomic mixing, etc.). It is well known that metallic oxides sputter at different rates, and many at rates slower than pure metal. Although the depth profiles presented in this paper and in the literature assume constant ion sputtering rates, the rates actually increase as the oxide is removed. Absolute sputter rates are unknown because the composition of the specimen is continuously changing with depth. The Auger peak-to-peak heights of P (120 eV), Mo (186 eV), K (252 eV), C (272 eV), Ca (292 eV), N (385 eV), Ti (418 eV), Cr (446 eV), O (510 eV), Fe (703 eV), Ni (848 eV) and Na (990 eV) were measured. Concentration profiles were evaluated using relative sensitivity factors from the manufacturer's handbook[10]. The following sensitivity factors were used: P (0.53), Mo (0.34), K (0.80), C (0.18), Ca (0.47), Ti (0.44), Cr (0.041), O (0.50), Fe (0.21), Ni (0.29), Na (0.21). The sensitivity factor of N (0.70) was determined on stoichiometric TiN thin film structure. Surface structure was investigated with a Solver PRO-M atomic force microscope (AFM) manufactured by NT-MDT Co. in semi contact mode. The images were Table 1. Presentation of analyzed samples Tabela 1. Predstavitev analiziranih vzorcev recorded with a resolution of 256 points per line on a 10^10 ^m area using commercial Si cantilevers NSG10 series with the Au conductive coating from NT-MDT Co., with stiffness 11.5 N/m, resonant frequency 255 kHz and tip curvature 10 nm as reported by the manufacturer[11]. The roughness amplitude Ra of medical implants surfaces was measured. Sample Material Osteosynthetic system Exposure Analysis method 1 AISI316L Compression plate Unused AES 2 AISI316L Screw Implanted AES 3 Ti6AI4V (golden coating) LCP plate Unused AES 4 Ti6AI4V (golden coating) LCP plate Implanted AES 5 Ti6AI4V (blue coating) Philos LCP system Implanted AES 6 Ti6AI4V (blue coating) Philos LCP system Implanted AFM 7 AISI316L Compression plate Unused AFM Results and discussion AES depth profiles of unused and used samples made from AISI 316L stainless steel are depicted in Figure 1a,b. Elements O, C, N, Na, Fe, Cr, Mo, and Ni have been found on an unused medical implant. Characteristic depth profile of the elements distribution is exhibited in Figure 1a, where oxygen concentrated, chromium enriched and iron impaired profiles are distinguished. The depletion of iron concentration and the enrichment of chromium on the outmost surface oxide may indicate a selective dissolution of iron and a preferential oxidation of Cr metal in the depth of the passive film during the manufacturing of medical device where passivation (soaking in acids and heating at elevated temperatures) is process occurring after mechanical and electropolishing. Also a smaller extent of Ni is enriched in the oxide layer. Inner composition on depth profile is near bulk. Iron oxides such as Fe3O4 and Fe2O3 are normally reduced to FeO by ion bombardment[12] and can therefore be identified even after sputtering. Figure 1. AES depth profile of AISI 316L sample, a.) unused medical implant, b.) used medical implant Slika 1. AES profilna analiza vzorca iz AISI 316L, a.) neuporabljen medicinski vsadek, b.) uporabljen medicinski vsadek Samples that have been implanted in the human body have surfaces which contain spots with layers of relatively thick organic material. In Figure 1b AES depth profile of stainless steel implant which has been in contact with living tissue is shown. The surface layer on the used implant changes compared to unimplanted sample, where on booth depth profiles inner composition is near bulk. Traces of S and K were additionally found on surface as depicted in Figure 2. Implanted sample consists of much thicker oxide layer compared to an unimplanted sample. All metal components are diminished on the surface and organic components are enriched. Iron and Ni concentrations increase rapidly from outermost side of the surface layer to deepness in depth profile. It can also be observed from Figure 1b that concentration of Cr increases at first and then starts to sink. This can be related to oxidation of Cr in oxide layer. 0(51 OeV) C(272eV) 1 I I Г! I I Г I J I Г ! 1 I Г Г! I I Г П Г Г1 M I [ II M 1 I I Г1 I F Г M I Г Г И Г f 1 I MT M Г[ 1 I IT 1 III! I I M 1 I Г! II [ I 1 I I Г1 I I Г J M I I 1 I I Г 1 J IT 1 I I ГМ I [ Г II I 0 100 200 300 400 500 600 700 800 900 1000 1100 Electron kinetic energy (eV) Figure 2. AES spectrum of an implanted AISI 316L sample surface Slika 2. AES spekter na površini vsadka iz AISI 316L According to the theory, the bipolar structure of the passive oxide film on stainless steel consists of excess metal ions or oxygen ion vacancies in the inner layer, which provide a positive fixed charge with an an-ion-selective property, as well as an excess oxygen ions or metal ion vacancies in the outer layer, which result in a negative fixed charge with a cation selective property. All cells and surfaces of the body carry an electrical charge, and the majority of the particles within the blood are negatively charged[13]. Figure 3. AES depth profile of unused titanium medical implant with golden colour protective layer Slika 3. AES profilna analiza neuporabljenega vzorca medicinskega vsadka narejenega iz titana z zlato obarvano zaščitno prevleko An AES depth profile of an unimplanted titanium sample with golden colour protection layer is shown in Figure 3. Elements O, Ti, N, P are compounds of an coating deposited on bulk titanium to increase bio-compatibility. Carbon in the depth profile is due to surface roughness and carbon low density. It is overestimated due to the back-scattering effect and preferential sputtering. High content of O, Ti and N is found due to the formation of protective layer and appears to consist of either mixture of TiO2 and TiNx or a Ti oxynitride (TiOxNy). D 2 4 e S 10 t: li 16 IB ID 22 24 Ж 2t 3D 32 24 3S 38 J3 42 M 1Ü 43 50 52 Sputter time (min) GO o' 2 i 6 S 10 II 14 16 13 20 22 24 26 28 30 32 34 36 40 42 44 «6 48 ЬО 52 54 Sputter time (min) Figure 4. AES depth profile of titanium medical implants with a.) golden coloured coating, b.) blue coloured coating Slika 4. AES profilna analiza titanovega medicinskega vsadka z a.) zlato obarvana prevleka, b.) modro obarvana prevleka Because coating preparation technique is unknown due to commercial nature of medical products, another possible interpretation is that the surface consists of a TiO2 layer covering the underlying Ti nitride. More detailed analysis, including angle resolved XPS, is necessary to distinguish between these interpretations. Significant change of the oxide composition in the surface region is because of contamination. Surface contamination on air-exposed samples is practically inevitable and the contamination layers on titanium oxide or oxynitride surfaces are most often dominated by oxygen and organic molecules with ingredients of Ca, Na, K and C. Chemical properties of two used titanium medical implants with different coatings colours were examined on spectrometer by AES. Difference in the colour is due to different coating composition as can be seen in AES depth profiles of golden (sample 4) and blue (sample 5) colour coating presented in Figure 4a, and 4b, respectively. Obtained depth profiles of implanted sam- ple 4 (Figure 4a) is significantly different compared to an unimplanted one (Figure 3). Penetration of Ca and P and also some Na was found in superficial stratum of the protective layer while K has been found relatively deeper. Sample 5 is different in composition and thickness. On its depth profile shown in Figure 4b, elements C and K were found on the surface and Ca and P in depth of the protective layer. Correlation between Ca and P can be linked to formation of calcium phosphate rich layer on its surface, very similar to hidroxyapatite which also prevents corrosion. Another advantageous property of formatted layer is that in the case of damaging the protective layer the titanium oxides and Ca-P layer regenerate[1]. This study presents surface characterization of unused and implanted biomaterial for trauma and orthopaedic medical products. A key issue in all trauma and orthopaedic medical applications of biomaterials is how the implanted material influences, and is influenced by, the biological re- Figure 5. A formation of calcium phosphate rich layer on titanium oxide film Slika 5. Nastanek obogatene plasti kalcijevega fosfata na substratu titanovega oksida sponse resulting from the contact between the biological system and the biomaterial. Understanding the surface phenomena of changes when the biomaterials are used in the biosystem can improve the knowledge about material - biosystem interactions. Several scenarios have been proposed for the events that may occur when a material surface is placed in contact with a biological system. The initial events in such scenarios are adsorption of water molecules, hydrated ions, and biomolecules, which form a so-called "conditioning film" on the biomaterial surface. Cells of the host tissue interact in this hydrated biomolecule coating, therefore the original surface properties of an implanted biomaterial constitute an important starting condition for the dynamics of the interface[14]. In Figure 5 formation of calcium phosphate rich layer similar to hidroxyapatite on hydrated surface is shown[1]. Furthermore the titanium with different coatings and deposition techniques show a wide range of chemical and physical properties, depending on how they are prepared and handled, and by using different surface preparation methods it is possible to control and vary selected surface properties of titanium over a relatively wide range. Different chemical properties of protective layer of used titanium base implants analysed in this study show different behaviour of deposed layer. On one formation of Ca-P rich layer was found on sample 5 while on sample 4 on such layer was found. The observed differences can be attributed mainly to the different textures of the sur- faces, where chemical surface analyses of samples gave only a limited picture of their surface characteristics. It is equally important to characterize the structural properties also, as they influence the biological function of biomaterials as well. The topography and roughness of polished AISI 316L stainless steel (Figure 6) and blue coated titanium (Figure 7) medical implants were analyzed with AFM. The roughness amplitude of electropol-ished and passivated medical implant of AISI 316L measured with AFM over area 10x10 ^m and the maximum Z-range of 120 nm, resulted in Ra value of 6.5 nm. Electropolishing produces surfaces which have a mirror like appearance with smooth corrugation on the scale of 10x10 ^m surveyed with AFM. In Figure 6 the individual granular structure is shown, with granule sizes of a few nanometres. AFM roughness measurements on blue colour coated titanium over areas of 10x10 ^m give Ra values of 68.6 nm, with maximum Z-range of 400 nm respectively. Higher roughness compared to polished AISI 316L samples can be explained with implantation of molecules on coating when implant was in contact with bodily fluids. 3D topography of wavy surface of blue coloured implanted sample is depicted in Figure 7, where raised and descended regions can be seen. In comparison to topography of stainless steel sample we can see fewer apexes which are nicely rounded and measured distance from highest to lowest point is increased. Figure 6. AFM 3D topography of unused AISI 316L medical implants (10*10 Mm) Slika 6. AFM 3D prikaz topografije površine jeklenega neuporabljenega vsadka iz AISI 316L (10*10 Mm) • < Figure 7. AFM 3D topography of used blue coated titanium trauma plate (10*10 Mm) Slika 7. AFM 3D predstavitev topografije rabljene modro prevlečene titanove plošče (10*10 Mm) The techniques utilised in this study were effective in the characterisation of the chemical composition, morphology and surface quality of the analysed surfaces. Analysed sample surfaces show a wide variety of structural and chemical properties. By using a combination of different experimental and analytical techniques it is possible to characterize the surface properties at a relatively high level of detail. Further studies using carefully prepared and systematically varied samples surfaces are necessary, and are likely to lead to an increased understanding of the biocompat-ibility of materials in question. This development is dependent on thorough surface characterization of the materials by a broad range of surface spectroscopic and microscopic techniques. Conclusions Detailed information about changes in the composition of a medical implant's surface can be obtained by AES and AFM. A comparison of depth profiling results between unused and implanted commercial medical devices used for bone osteosynthesis using AES depth profiling with 3 keV Ar+ ion beams and physical properties examined by AFM showed that: • Oxides grow when implant is contact with bodily fluids on both stainless steel and titanium devices. • Type of changes in chemical composition depends on used protective coating as has been shown on titanium implants with different coatings. • Main factor for the colour change seems is the oxide thickness which has been confirmed by the ion sputtering of golden coated sample. • Backscattering effect and preferential sputtering increase concentration of carbon especial on rougher titanium surfaces. • Surfaces of stainless steel implants are much smoother, where average roughness Ra = 6.5 nm has been measured, while on coated titanium average roughness Ra was 68.6 nm, since titanium surfaces are coated with hard coatings. Povzetki Karakterizacija površin medicinskih vsadkov iz titana in nerjavnih jekel Podrobne informacije o spremembah v sestavi površine medicinskega vsadka lahko dobimo z metodama AES in AFM. Primerjava globinskih profilov novega in že uporabljenega komercialnega medicinske -ga vsadka za oseosintezo kostnega tkiva z AES globinsko profilometrijo s 3 keV Ar+ ioni in fizikalne lastnosti preiskane z AFM so pokazale: • Površinski oksidi rastejo pri kontaktu vsadka s telesnimi sokovi, tako na vsadkih iz nerjavnega jekla, kot tudi na vsadkih iz titana. • Vrsta spremembe v kemijski sestavi je odvisna od vrste zaščitne prevleke, ki je bila nanesena na vsadek iz titana. • Barva zaščitne prevleke je odvisna od re- ferenčne debeline oksida, kar je bilo potrjeno pri ionskem jedkanju zlato obarvane prevleke. • Na zasenčenih površinah, ki jih pri ionskem jedkanju ne dosežemo izmerimo višjo koncentracijo ogljika, še posebej na bolj hrapavih površinah. • Površine vsadkov, narejenih iz neijav-nega jekla so bolj gladke, s povprečno vrednostjo Ra = 6.5 nm. Na površinah titanovih vsadkov je bila izmerjena večja povprečna hrapavost Ra = 68.6 nm, kar je posledica nanosa zaščitne prevleke. Acknowledgements The authors would like to thank to Mr. B. Pracek and dr. J. Kovac, Jozef Stefan Institute, for technical assistance. References [5] [1] [2] [3] [4] Balazic, M., Bombac, D., Brojan, M., Caram, R. Jr., Kosel, F., Kopac, J. (2007): Titanium and titanium alloy applications in medicine. Surface Engineered Surgical Tools and Medical Devices. Editors: J. Jackson, W. Ahmed. Springer, ISBN: 978-0-38727026-5. Johnson, SL. (2006): Surface studies of potentially corrosion resistant thin film coatings on chromium and type 316l stainless steel: Ph.D. Thesis. Kansas, Kansas State University, pp. 50-58. Windecker, S., Mayer, I., De Pasquale, G., Maier, W., Dirsch, O., De Groot, P., Wu, Y.P., Noll, G., Leskosek, B., Meier, B., Hess, o.M. (2001): Stent Coating With Titanium-Nitride-Oxide for Reduction of Neointimal Hyperplasia. Circulation 104. pp. 928. Lausmaa, J., Kasemo, B. (1990): Surface spectroscopic characterization of titanium implant materials. Applied Surface Science 44. pp. 133-146. [6] [7] [8] Machnee, CH., Wagner, WC., Jaarda, MJ., Lang, BR. (1993): Identification of oxide layers of commercially pure titanium in response to cleaning procedures. International Journal of Oral & Maxillofacial Implants 8. pp. 529-533. Wälivaara, B., Aronsson, Bo., Rodahl, M., Lausmaa, J., Tengvall, P. (1994): Titanium with different oxides: in vitro studies of protein adsorption and contact activation. Biomaterials 9. pp. 827-834. Zitter, H., Plenk, HJ. (1987): The electrochemical behaviour of metallic implant materials as indicator of their biocompatibility. Journal of Biomedical Materials Research 21. pp. 881896. solar, RJ., Pollack, sr., Korostoff, E. (1979): In vitro corrosion testing of titanium surgical implant alloys: an approach to understanding titanium release from implants. Journal of Biomedical Materials Research 13. pp. 217-250. [91 William, DF. (1976): Corrosion of implant materials. Annual Reviews of Material Science 6, pp. 237-265. [101 Davis, LE., MacDonald, NC., Palmberg, PW., Riach, GE., Weber RE. (1976): Handbook of Auger electron spectroscopy 2nd ed. Physical Electronics Industries Inc., Eden Prairie, Minesota. [11] NT-MDT - Molecular devices and tools for nano technology. Dostopno na svetovnem spletu: http://www.ntmdt-tips.com/catalog/golden/cond/non/au/ products/NSG10_Au_50.html [12] Sundgren, J-E., Bodo, P., Lundström, I. (1986): Auger electron spectroscopic studies of the interface between human tissue and implants of titanium and stainless steel. Journal of Colloid andInterface Science 110. pp. 9-20. [13] Shih, CC., Shih, CM., su, YY., su, LHJ., chang, MS. (2004): Effect of surface oxide properties on corrosion resistance of 316L stainless steel for biomedical applications. Corrosion Science 46. pp. 427-441. [14] Lausmaa, j. (1996): Surface spectroscopic characterization of titanium implant materials. Journal of Electron Spectroscopy and Related Phenomena 81. pp. 343-361. Hot forming of Zn and ZnCuTi, ZnPb alloys Toplo preoblikovanje Zn in zlitin ZnCuTi ter ZnPb Peter Fajfar 1, Radomir Turk 1, Bojan Breskvar 2, Milan Terčelj1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva cesta 12, SI-1000 Ljubljana, Slovenia; E-mail: peter.fajfar@ntf.uni-lj.si, rado.turk@ ntf.uni-lj.si, milan.tercelj@ ntf.uni-lj.si 2 Institute of metals and technology, Lepi pot 11, SI-1000 Ljubljana, Slovenia; E-mail: bojan.breskvar@imt.si Received: September 19, 2007 Accepted: October 25, 2007 Abstract: Hot compression tests of pure zinc and zinc alloyed with copper, titanium and lead have been carried out on Instron 1255. Since the testing machine was not equipped with the proper heating system, a new heating device was developed. Specimens and compression tools were heated using oil bath. Specimens were in as-cast and pre-deformed state. Tests were performed at two constant tools speeds: 0.2 and 0.01 m/s and three temperatures: 80, 150 in 210 °C. Constants for flow stress description of Hajduk-Hensel equation were detrermined. The comparison between measured and predicted flow stresses are in good accordance. Izvleček: Za določitev krivulj tečenja so bili z uporabo preizkuševalne naprave Instron 1255 narejeni topli tlačni preizkusi za čist Zn in zlitini: ZnCuTi ter ZnPb. Ker preizkuševalni stroj ni bil opremljen s sistemom za ogrevanje vzorcev, smo izdelali napravo, s katero smo vzorce in tudi orodje ogrevali v oljni kopeli. Vzorci so bili tako v litem kot tudi predhodno deformiranem stanju. Preizkuse smo vodili pri dveh konstantnih hitrostih pomika orodja: 0,2 in 0,01 m/s ter treh temperaturah: 80, 150 in 210 °C. Določene so bile konstante za izračun krivulj tečenja po Hajduk-Hensel. Izračunane vrednosti so v dokaj dobrem ujemanju z izmerjenimi vrednostmi. Key words: Zn, Zn alloys, compression test, flow curves Ključne besede: Zn, Zn zlitine, tlačni preizkusi, krivulje tečenja Introduction Zinc is the fourth most common metal in use. Over 7 million tons of zinc is produced annually worldwide. Only annual production of iron, aluminium and copper are major. Zinc and zinc alloys are used in the form of coatings, casting and wrought zinc products. Wrought zinc and zinc alloys may be obtained as rolled strip, sheet and foil; extruded rod and shapes; and drawn rod and wire. These metals exhibit good resistance to corrosion in many types of service. Nearly half of annual production is used for galvanizing to protect steel from corrosion. Approximately 19 % are used to produce brass and 16 % go into the production of zinc base alloys to supply e.g. the die casting industry. Significant amounts are also utilized for compounds such as zinc oxide and zinc sulphate and semi-manufactures including roofing, gutters and down-pipes. Main application areas are construction, transport, consumer goods and electrical appliances and general engineering. Wrought zinc is easily machined using standard methods and tools. However, if it is necessary to machine zinc containing exceedingly coarse grains, the metal should be heated to a temperature between 70 and 100 °C in order to avoid cleavage of crystals. Zinc strips are usually produced from 25 to 100 mm thick slabs. Finish rolling in the temperature range 120 to 150 °C is required to obtain a bright surface and high ductility. Rolled zinc is produced as pure zinc and in seven basic alloys. Pure zinc is brittle at room temperature and at temperatures above 150 °C, being workable only in the range between 100 °C and 150 °C. When alloyed with copper and titanium, zinc sheet is very creep resistant. This alloy is manly used in building industry for roofing, flashing and weathering applications. In common with many other metals and alloys, wrought zinc creeps under constant loads that are substantially less than its ultimate strength; that is, wrought zinc does not have clearly defined elastic module, and hence creep data from service tests must be used in designing for strength and rigidity under conditions of continuous stress. Rolled zinc alloyed with lead is mostly used for drawn or formed articles requiring some rigidity. It must be deformed under light continuous load at elevated temperatures[1L [2]. The aim of presented work is to intensify productivity on reversing hot rolling mill with slab lengthening. Industrial measurements of loads on the mechanical side (torque on the mean shaft) and on the energetic side (current, voltage, revolutions of electromotor, etc.), and laboratory test of rolled material were carried out. Due to increasing length of the slab, the rolling time is extended. This causes the change of the slab temperature evolution and consecutive the change of rolling mill load. Because of all these changes new pass schedule must be optimized. Flow curves are very important input data for numerical modelling of rolling pass schedules. Accurate knowledge of the mechanisms acting during hot rolling is important for the manufacture of high quality products, as well as for design of optimum pass schedules. Experimental Initial state of specimens In the present study pure zinc and two zinc alloys ZnPb (0.8 %Pb) and ZnCuTi (0.11 % Cu, 0.1 % Ti) in as-cast and deformed state were investigated. For hot compression tests cylindrical specimens with initial heights of 20 mm and initial diameters of 15.5 mm were used. For the as-cast state specimens were machined from the centre of gravity cast block of dimensions 40x80x1500 mm. The bottom of the gravity die was cooled down by water that caused appearance of fine grains. In the centre part of the block the crystallization was oriented similar to macrostructure founded in plates produced in real technological process. For this reason the speci- mens were taken from the upper two thirds of the block. Macrostructure of the transverse section in the centre of the block is presented in Figure 1. Specimens for pre-deformed state were taken from the centre of the strip which was 30 % deformed. Macrostructure of the transverse section in the centre of deformed plate shows that direction of recrystallized grains and direction of dendrite in as-cast are nearly the same (Figure 2). This effect is not presented in the specimens (Figures 3, 5 and 7) what confirmed the accurate procedure of taking specimens from plates. In deformed specimens (Figure 3b, 5b and 7b) the re-crystallization of crystal grains is noticed. To clarify initial state of specimens micro-structures are presented as well (Figures 4, 6 and 8) where uniformity is obvious. Figure 1. Transverse section of Zn cast block Slika 1. Prečni presek ulitka iz Zn Figure 2. Transverse section of 30 % deformed Zn plate Slika 2. Prečni presek 30 % toplo deformiranega ulitka iz Zn Figure 3. Macrostructure of Zn specimen: as-cast (a), deformed (b) Slika 3. Makrostruktura Zn vzorca: ulit (a), deformiran (b) Figure 4. Microstructure of Zn specimen of as-cast (a), deformed (b) Slika 4. Mikrostruktura Zn vzorca: ulit (a), deformiran (b) Figure 5. Macrostructure of ZnCuTi specimen: as-cast (a), deformed (b) Slika 5. Makrostruktura ZnCuTi vzorca: ulit (a), deformiran (b) Figure 6. Microstructure of ZnCuTi specimen: as-cast (a), deformed (b) Slika 6. Mikrostruktura ZnCuTi vzorca: ulit (a), deformiran (b) Figure 7. Macrostructure of ZnPb specimen: as-cast (a), deformed (b) Slika 7. Makrostruktura ZnPb vzorca: ulit (a), deformiran (b) Figure 8. Microstructure of ZnPb specimen: as-cast (a), deformed (b) Slika 8. Mikrostruktura ZnPb vzorca: ulit (a), deformiran (b) Compression tests A material testing machine Instron 1255 was used for compression testing. Testing was performed at two constant punch velocities: 0.01 and 0.2 m/s and three temperatures: 80, 150 in 210 oC what correspond technological condition of hot forming. Specimens were heated with use of special heating device (Figure 9). This device enables heating of specimens in the oil bath. Oil is used as a lubricant at the contact tool- specimen as well. In this way cooling of specimen when transported from furnace to tools was hindered. Power of a heater was 1 kW. Temperature field was homogeneous due the mechanical mixing of the oil bath. Control thermocouple was placed in the tool area. Temperature oscillation was in range of ±2.5 oC. Jaws of the testing machine were protected against overheating with water cooling. 1. specimen 2. tool 3. oil container 4. heater 100 W 5. holder of the heater 6. control thermocouple 7. power supply for the heater 8. asbestos isolation 9. cold winding 10. mixer 11. cover 12. holder of the cover 13. cylinder oil level Figure 9. Hot compression test device Slika 9. Shema naprave za tlačne preizkuse v vročem Determination of flow curves When performing compression tests, friction between specimen and tool can result in tangential stresses at the contact surfaces, which increase the forming force. Friction has negligible influence on elastic deformation but it causes barrel-shaped specimen on plastic deformation. In extreme cases, this can lead to sticking the specimen to the tool's surface. This is why we have to determine the coefficient of friction, considering the roughness of the tool's and specimen's surface, lubrication, temperature and the strain rate. The coefficient of friction was determined using the Burgdorf's methods. This value was lower than 0,02 and was taken into account while defining hot flow curves. Considering the coefficient of friction we calculated flow stresses for all materials at different thermo mechanical conditions and initial states from measured load and displacement of compression tool[3]. A-F-h a = (1) о F - force h - instantaneous specimen height ho - initial specimen height do - initial specimen diameter i - coefficient of friction Because flow stress curves are defined at constant temperature and strain rate, thermo mechanical constants for the selected mathematical equation for flow curves were defined using experimentally acquired values with linear regression. These values are written in Table 1. Matching the measured (dashed line) and the calculated values (solid line) is shown on Figures 7, 8 and 9. Flow curves can be written in the following form[4]: (2) (3) (4) where £ is the strain, e is the strain rate, ü is the temperature, a A}, A2, A3, m}, m2, m3 are constants, ho is the initial slab height, h is the instantaneous slab height, and v is the tool velocity. A new constant B (Table 1) replaces product of the constants a,, A , A , and A,. fO P 2 3 Results and discussions All three materials were deformed in the temperature range between 80 and 210 °C. In this temperature range flow stresses increase with strain trough work hardening up to a critical strain beyond which softening is initiated. Softening includes dynamics recovery and dynamic recrystallization where substructure rearrangements and dislocation reduction lead to decrease in flow stress. With decreasing strain rate or increasing temperature, the strain hardening effect becomes weaken, while the degree of strain softening becomes notable. This phenomena is more evident is as-cast materials. Under a constant strain rate, the peak stress and the peak strain increased with decreasing temperature (Figure 13). Under the same temperature, the peak stress and the peak strain increased with increasing strain rate. Table 1. The values of thermo mechanical constants Tabela 1. Vrednosti termomehanskih konstant Material Initial state B [MPa] m, m2 m3 m4 Zn as-cast 545 0.00472 0.104 1.578 0.116 deformed 694 0.00582 0.257 1.629 0.116 ZnPb as-cast 888 0.00547 0.347 1.682 0.089 deformed 803 0.00599 0.299 1.441 0.100 ZnCuTi as-cast 1027 0.00460 0.407 1.890 0.061 deformed 619 0.00531 0.210 1.085 0.085 ZnPb alloy indicated minimum values of flow stress in as-cast state at both punch velocities. At the velocity of 0.2 m/s and at the temperature of 210 °C are the values of flow stresses for pure zinc essential greater than for ZnCuTi and ZnPb alloys, at 80 °C they are all nearly the same. Flow stresses for ZnCuTi and ZnPb are similar at higher velocity while flow stresses for Zn in Zn-CuTi are similar at lower velocity. In deformed state and at punch velocity 0.2 m/s values of flow stresses for ZnTiCu and ZnPb are similar to pure Zn with the exception of those at 210 °C where they are all very similar. At lower velocity is the value of flow stress for pure Zn lower as is case for ZnCuTi and ZnPb. At the temperature 210 °C flow stresses for Zn and ZnPb are similar, while for ZnCuTi is higher. Figures 10, 11 and 12 show the stressstrain curves of pure zinc and two alloys ZnCuTi and ZnPb under different deformation conditions. Dynamic recrystalliza-tion (DRX) is evident in all cases, even at increasing strain rates. Although calculated flow stress curves have similar shapes as the measured ones, they cannot follow the processes of dynamic softening, present at higher temperatures. Figure 10. Flow stress curves for Zn in as-cast: v = 0.01 m/s (a), v = 0.2 m/s (b), and deformed state: v = 0.01 m/s (c), v = 0.2 m/s (d) Slika10. Krivulje tečenja za Zn v ulitem: v = 0,01 m/s (a), v = 0,2 m/s (b) in deformiranem stanju: v = 0,01 m/s (c), v = 0,2 m/s (d) Figure 11. Flow stress curves for ZnCuTi in as-cast: v = 0.01 m/s (a), v = 0.2 m/s (b), and deformed state: v = 0.01 m/s (c), v = 0.2 m/s (d) Slika 11. Krivulje tečenja za ZnCuTi v ulitem: v = 0,01 m/s (a), v = 0,2 m/s (b) in deformiranem stanju: v = 0,01 m/s (c), v = 0,2 m/s (d) Figure 12. Flow stress curves for ZnPb in as-cast: v = 0.01 m/s (a), v = 0.2 m/s (b), and deformed state: v = 0.01 m/s (c), v = 0.2 m/s (d) Slika 12. Krivulje tečenja za ZnPb v ulitem: v = 0,01 m/s (a), v = 0,2 m/s (b) in deformiranem stanju: v = 0,01 m/s (c), v = 0,2 m/s (d) Figure 13. Peak stresses for as-cast (a) and deformed state (b) Slika 13. Natezne trdnosti v ulitem (a) in deformiranem stanju (b) Conclusions 1. True stress-strain curves for Zn and its alloys were defined at known thermo mechanical parameters. 2. Multilevel linear regression method was used to define thermo mechanical constants in dependence of initial state of material, strain, strain rate and temperature. These constants were obtained for extensive area of the thermo mechanical parameters and therefore they render impossible to describe all fineness, which have influence to stress-strain dependences. 3. For more accurate estimation of flow stress, applied mathematical expression should be improved or the area of thermo mechanical parameters should be tightened. 4. In as-cast state softening process is more evident. Povzetek Toplo preoblikovanje Zn in zlitin ZnCuTi ter ZnPb Raziskali smo tople preoblikovalnosti čistega cinka, zlitine ZnPb (0,8 %Pb) in zlitine ZnCuTi (0,11 % Cu, 0,1 % Ti) v litem in predhodno deformiranem stanju (30 %). Za določitev preoblikovalnih lastnosti smo uporabili tlačni preizkus. Preizkušan-ci so bili valjčki premera 15,5 mm in višine 20 mm. Za lito stanje so bili valjčki odvzeti iz sredine ulitih trakov dimenzije 40x80x1500 mm. Ker je bilo dno kokile vodno hlajeno, se je v tem področju tvorilo območje drobne kristalizacije. Srednji del traka je imel značilno območje usmerjene kristalizacije, ki je bilo primerljivo z dejansko makrostrukturo plošč izdelanih v realnih pogojih tehnološkega procesa. Tudi v deformiranih ploščah je še vedno razvidna določena usmerjenost rekristali-ziranih zrn v smeri ulitih dendritskih zrn. Ta usmerjenost pa ni razvidna v makro-strukturi vzdolžnih presekov valjčkov, kar je dokaz o pravilnem odvzemu vzorcev iz plošč. Ker preiskuševalni stroj za tlačne preizkuse ni bil opremljen s sistemom za ogrevanje vzorcev, smo izdelali napravo, s katero smo vzorce in tudi orodje ogrevali v oljni kopeli. Preizkuse smo izvajali pri dveh hitrostih pomika orodja: 0,2 in 0,01 m/s ter treh temperaturah: 80, 150 in 210 °C. Iz izmerjenih vrednosti sil in deformacij in z upoštevanjem koeficenta trenja (<0,2) smo določili preoblikovalne trdnosti. Ker so krivulje tečenja definirane za konstantne temperature in hitrosti deformacij, smo na osnovi eksperimentalno dobljenih vrednosti z linearno regresijo določili ter-momehanske konstante za izbran matematičen zapis krivulj tečenja. Analitično izračunane vrednosti iz funkcijskega izraza se z regresijsko dobljenimi konstantami za eksperimente celotnega variiranja termo-mehanskih parametrov bolj ali manj prilagajajo izmerjenim rezultatom. Izračunane krivulje imajo sicer podobno obliko t.j. najprej naraščajoč potem pa padajoč značaj, ne morejo pa povsem slediti procesom dinamičnega mehčanja. Vsi preiskovani materiali so v temperaturnem območju med 80 in 210 °C nahajajo v toplem stanju, to pomeni, da začetnemu utrjevanju sledi po dosegu kritične deformacije mehčanje dinamičnega značaja. Maksimumi napetosti tečenja teh krivulj se z naraščajočo temperaturo pomikajo k nižjim deformacijam, z naraščajočo hitrostjo deformacije pa proti višjim vrednostim deformacij. Ta zakonitost je podobna za vse preiskovane materiale. Nastopajo bistvene razlike v poteku preoblikovalnih trdnosti, če imamo za izhodišče enkrat lito drugič pa deformirano stanje. V litem stanju je intenziteta mehčanja večja, kritična napetost tečenja pa je dosežena že pri nekoliko nižjih deformacijah kot v deformiranem stanju. V litem stanju so vrednosti preoblikovalnih trdnosti pri obeh hitrostih stiskanja najnižje za zlitino ZnPb. Pri hitrosti stiskanja 0,2 m/s in temperaturi 210 °C so vrednosti za čisti Zn bistveno večje od ostalih dveh, medtem ko so si vrednosti pri 80 °C približno enake. Pri višji hitrosti sta si preoblikovalni trdnosti za ZnCuTi in ZnPb podobni, pri nižji hitrosti pa sta si podobni preoblikovalni trdnosti za Zn in ZnCuTi. V deformiranem stanju se pri hitrosti stiskanja 0,2 m/s vrednosti preoblikovalnih trdnosti za ZnTiCu in ZnPb bistveno ne razlikujeta in sta višji od čistega Zn razen pri temperaturi 210 °C, ko so si vrednosti enake. Tudi pri hitrosti stiskanja 0,01 m/s je preoblikovalna trdnost za Zn nižja kot pri ostalih dveh kvalitetah. Pri temperaturi 210 °C pa sta si vrednosti za Zn in ZnPb enaki, medtem, ko je preoblikovalna trdnost za ZnCuTi višja. Zlitine se med seboj glede na legirne elemente ločijo po zahtevani napetosti tečenja in v splošnem velja brez izjem, da je proces mehčanja, ki ga pripišemo rekristaliza-ciji deloma pa tudi popravi, intenzivnejši pri litem stanju. References [1] Schweitzer, P.A. (2003): Metalic materi- als: Physical, mechanical, and corrosion properties. New York, Basel: Marcel Dekker, Inc., 712 p. [2] Prasad, Y.V.R.K., Sasidhara, S. (1997): Hot working guide: A compendium of processing maps. ASM International, 543 p. [3] Pawelski, О. (1977): Theoretische Grun- dlagen des Freiformenschmiedens. Stahl und Eisen 5. [4] Hensel, a., Spittel, T. (1978): Kraft und Arbeitsbedarf Bildsamer Formgebungs-verfahren. Leipzig, Deutscher Verlag für Grundstoffindustrie, 528 p. Varjenje močno legiranih jekel z oplaščenimi elektrodami Welding of high-alloy steels with covered electrodes Rajko Kejžar 1, Lado Kosec 2, üros Kejžar3 1 Univerza v Ljubljani, Fakulteta za strojništvo, Aškerčeva cesta 6, 1000 Ljubljana; E-mail: rajko.kejzar@fs.uni-lj.si 2 Univerza v Ljubljani, Naravoslovnotehniška fakulteta, Oddelek za materiale in metalurgijo, Aškerčeva cesta 12, 1000 Ljubljana; E-mail: kosec@ntf.uni-lj.si 3 ISKRA VARJENJE, Stegne 21c, 1000 Ljubljana; E-mail: uros.kejzar@iskra-varjenje.si Received: April 12, 2007 Accepted: October 1, 2007 Izvleček: Oplaščene elektrode so primerne za varjenje in navarjanje močno legiranih jekel. Var lahko legiramo tako preko legirane elektrodne žice, kot tudi preko elektrodne obloge. Zgradba elektrode pomembno vpliva na njeno uporabnost, ki v največji meri zavisi od ionizacije obloka, odtaljevanja in legiranja vara. Pri varjenju z oplaščenimi elektrodami je sestava elektrodne obloge, od katere zavisi stabilnost ter produktivnost in izkoristek varjenja, odločilna za nastajanje varilne žlindre in osnovnega pomena za varilnotehnične lastnosti elektrode. Varjenje s tanko oplaščenimi močno legiranimi elektrodami (legiranje vara preko žice) je neproduktivno, ker je odtaljevanje grobo kapljičasto. Pri varjenju z debelo oplaščenimi močno legiranimi elektrodami (legiranje vara preko obloge), pa je odtaljevanje fino kapljičasto - pršeče, kar povzroči izboljšanje produktivnosti. Težave pa nastopijo pri varjenju v prisilnih legah. Zaradi visokih minimalnih izkoristkov varjenja pride do omejitev glede uporabnosti teh elektrod. Abstract: Covered electrodes are suitable for welding and surfacing of high-alloy steels. Alloying of the weld metal can be accomplished by both an electrode wire and an electrode covering. The electrode composition has a major influence on its usability that mainly depends on arc ionisation, melting-off, and alloying of the weld metal. In welding with a covered electrode, the electrode-covering composition, on which stability, welding productivity, and efficiency depend, is a deciding factor in the formation of welding slag and of basic importance for welding characteristics of the electrode. Welding with thin-coated high-alloyed electrodes (alloying of the weld metal by the wire) is unproductive since melting proceeds in coarse drops. In welding with thick-coated high-alloyed electrodes (alloying of the weld metal by the covering), melting proceeds in fine droplets, which increases productivity. Difficulties, however, are encountered in welding out of po- sition. Because of high minimum welding efficiencies, there are certain limitations as to the applicability of these electrodes. Ključne besede: oplaščene elektrode, odtaljevanje, legiranje vara preko žice, le- giranje vara preko obloge Key words: covered electrodes, melting-off, alloying of the weld metal by the wire, alloying of the weld metal by the covering Uvod Pri varjenju z oplaščenimi elektrodami je sestava oplaščenja bistvenega pomena za kvaliteto zvarov in navarov. Oplaščenje odločilno vpliva na stabilnost varjenja (ionizacija obloka) in odtaljevanje elektrode[1]. Pri varjenju z rutilno in kislo oplaščenimi elektrodami (npr. Finkord), je varjenje zelo stabilno - oblok je dobro ioniziran, zato običajno varimo z izmeničnim ali pa enosmernim tokom na minus pol, odtaljevanje je finokapljičasto in pršeče z zelo malo kratkih stikov (glej sliki 1 in 2). Pri varjenju z bazično oplaščenimi elektrodami (npr. EVB 50), pa moramo zaradi slabe ionizacije obloka variti z enosmernim tokom na plus pol, odtaljevanje je grobo kapljičasto s pogostimi kratkimi stiki (glej sliki 1 in 2). U/V I EVB 50 0 50 100 150 200 250 300 350 400 450 500 Slika 1. Časovno spreminjanje varilne napetosti pri varjenju z elektrodama EVB 50 in Finkord[2] Figure 1. Time variation of welding voltage in welding with electrodes EVB 50 and Finkord[2] Slika 2. Statistična porazdelitev napetosti in ocena deleža kratkih stikov pri varjenju z elektrodama EVB 50 in Finkord[1] Figure 2. Statistical distribution of voltage and assessment of fraction of short circuits in welding with electrodes EVB 50 and Finkord[1] Preko elektrodne obloge lahko tudi legi-ramo navar. Tako sestava legirane varilne žice, kot tudi dezoksidanti in legirni elementi v oplaščenju, vplivajo na odtaljeva-nje in stabilnost varjenja. Odtaljevanje pri oplaščenih elektrodah, ki so izdelane iz močno legiranih žic, je bolj grobo kaplji-často, kot odtaljevanje pri oplaščenih elektrodah, pri katerih je legiranje in dezoksi-dacija preko elektrodne obloge[3],[4]. Ker je oplaščenje elektrode lahko rutilno kislo ali pa bazično, poznamo najmanj štiri osnovne tipe elektrod[4]. I. Rutilno kislo oplaščene elektrode: a) legiranje vara preko elektrodne žice in b) legiranje vara preko elektrodne obloge II. Bazično oplaščene elektrode: d) legiranje vara preko elektrodne žice in e) legiranje vara preko elektrodne obloge Odtaljevanje močno legiranih elektrod Legiranje navara preko elektrodne žice Tako rutilne kot tudi bazične elektrode so tanko oplaščene (f.opl = 1,4). Preko obloge le dezoksidiramo in stabiliziramo navar z manganom in niobijem. Odtaljevanje rutilno oplaščenih močno legiranih elektrod je bolj fino kapljičasto, podobno kot odtaljevanje pri varjenju s Finkord elektrodami, pri katerih zaradi oksidativnosti obloge pride do pršečega odtaljevanja (eksplozije kapljic, zaradi nastajanja ogljikovega monoksida; [C] + [O] = {CO}). Pri bazično oplaščenih močno legiranih elektrodah pa je odtaljevanje grobo kapljičasto - celo bolj kot pri varjenju z elektrodami EVB 50. Velikost odta-ljenih kapljic je nad 4 mm. Pri varjenju z rutilno oplaščenimi močno legiranimi elektrodami pa se odtaljujejo predvsem bolj drobne kapljice (pod 2 mm). Kemična sestava kapljic je tako pri rutilno oplaščenih elektrodah, kot tudi pri bazično oplaščenih elektrodah, zelo podobna kemični sestavi vara (tabela 1)[5]. Tabela 1. Kemične sestave varov in odtaljenih kapljic različne velikosti pri varjenju z močno legiranimi elektrodami (legiranje vara preko žice) Table 1. Chemical compositions of weld metals and melted droplets of various sizes in welding with high-alloyed electrodes (weld-metal alloying by the wire) Vzorec / Sample Kemična sestava / Chemical composition (%) Velikost kapljice / Droplet size Si Cr Ni Nb Rutilno opl. el / Rutile: Var / weld metal 1,38 16,6 8,5 1,41 Nad / above 2 mm 1,80 16,9 9,1 0,75 Nad / less than 2 mm 1,87 17,6 9,2 0,75 Bazično opl. el. / Basic: Var / weld metal 1,32 18,1 8,8 1,30 Nad / above 4 mm 1,16 19,4 8,8 0,84 Iz rezultatov kemičnih analiz je razvidno, da so izgube legirnih elementov zaradi odgorevanja in dezoksidacije vara pri rutilno oplaščenih elektrodah večje, kot pri bazično oplaščenih. Pri bazično oplaščenih elektrodah je že na stopnji kapljice dezo-ksidacija zaključena. Pri rutilno oplaščenih elektrodah pa visoka vsebnost silicija v kapljici še na stopnji kopeli dezoksidira var. Mikrostruktura kapljic, ki nastanejo pri varjenju tako z rutilno kislimi, kot tudi bazičnimi elektrodami, je ne glede na njihovo velikost podobna mikrostrukturi vara, ki je drobnozrnata avstenitna (slika 3 in 4). Slika 3. Mikrostruktura kapljice (pod 2 mm) pri varjenju z rutilno oplaščeno elektrodo - pov. 50 x Figure 3. Droplet microstructure (below 2 mm) in welding with rutile electrode. x50 Slika 4. Mikrostruktura kapljice (nad 4 mm) pri varjenju z bazično oplaščeno elektrodo - pov. 50 x Figure 4. Droplet microstructure (above 4 mm) in welding with basic electrode. x50 Legiranje in dezoksidacija vara je zelo ne-izotermičen proces[6]. Ravnotežje reakcij dezoksidacije in hitrost procesov se s temperaturo spreminjata. Na stopnji kapljice potekajo procesi bistveno hitreje, kot v kopeli vara. Pri rutilno oplaščenih elektrodah poteka dezoksidacija in legiranje, kot je razvidno iz kemičnih sestav vara in kapljic, zelo zanimivo. Predvsem niob, ki kapljice legira preko obloge, pri visokih temperaturah obloka močno reducira SiO2 iz obloge in s tem povzroči visok prigor Si v kapljici. Visok silicij pa pri nižji temperaturi kopeli vara reducira dezoksidacijske produkte (predvsem Nb2O5). Vsebnost silicija v navaru se zato zniža, nioba pa zviša. Dezoksidacija pri varjenju z rutilno kislimi elektrodami se zaključi šele v kopeli vara, pri varjenju z bazično oplaščenimi elektrodami (legiranje preko žice) pa je praktično zaključena že na stopnji kapljice. Legiranje navara preko elektrodne obloge Elektrode pri katerih poteka legiranje na-vara preko elektrodne obloge so debelo oplaščene (f-opl. = 1,85). Preko obloge moramo legirati navar z zadostno količino legirnih elementov. Izkoristki varjenja so zato pri teh elektrodah zelo visoki - okoli 180 %, kar je zelo neugodno pri varjenju v prisilnih legah[4]. Tudi odtaljevanje in legiranje vara poteka nekoliko drugače, kot pri varjenju s tanko oplaščenimi elektrodami, ko legiranje navara poteka preko močno legirane elektrodne žice. Odtaljevanje žice, ki je pri elektrodah z veliko vsebnostjo legirnih elementov in dezo-ksidantov v oblogi, nelegirana in običajno tudi nepomirjena, je nekoliko bolj fino ka-pljičasto. Največja razlika pa je v prenosu legirnih elementov iz obloge v var, ki delno poteka preko legiranja kapljic, delno pa v zelo finih kapljicah kar direktno v var. Posledica tega načina prenosa je, da imamo tudi pri varjenju z bazično oplaščenimi elektrodami (legiranje preko obloge) poleg večjih tudi drobne kapljice - podobno, kot pri varjenju z rutilno oplaščenimi elektrodami. Iz kemične analize kapljic pa je razvidno, da so drobne kapljice raztaljeni dodatki kovin in zlitin, ki so dani v oblogo za legiranje in dezoksidacijo vara (tabela 2)[5]. Iz rezultatov kemičnih analiz čistih varov in odtaljenih kapljic je lepo vidno, da večji del procesov legiranja in dezoksidacije var poteče že na stopnji kapljice (preko 90 %). Kovinski dodatki v elektrodni oblogi za legiranje in dezoksidacijo vara, legirajo že kapljice, ki se odtaljujejo od nelegirane žice. Sestava večjih odtaljenih kapljic je praktično enaka sestavi vara. Odstopanja so le pri legiranju in dezoksidaciji vara s silicijem in niobom pri varjenju z rutilno kislo oplaščenimi elektrodami, ker niob pri visokih temperaturah obloka reducira SiO2 v oplaščenju ter povzroči višji prigor silicija v kapljici. Na stopnji kopeli vara pa silicij reducira nekatere dizoksidacijske produkte, kar povzroči znižanje Si in porast Nb v čistem varu, podobno kot smo ugotovili tudi pri varjenju z rutilno kislo oplaščenimi elektrodami, ko je bilo legiranje vara preko žice. Mikrostruktura večjih kapljic je finozrna-ta avstenitna in že podobna mikrostrukturi varov, le dezoksidacija še ni povsem zaključena. Pri kapljicah bazično oplaščenih elektrod (slika 5), je potekla bolj daleč, kot pri kapljicah rutilno oplaščenih elektrod (slika 6), kar je razvidno iz bolj učinkovitega očiščenja kovine kapljice. Vse zelo drobne kapljice (pod 2 mm), tako pri bazično, kot tudi rutilno kislo opla- ščenih elektrodah (slika 7), pa so skupek dezoksidacijskih in legirnih dodatkov in so si glede mikrostrukture povsem podobne[5]. Tabela 2. Kemične sestave čistih varov in odtaljenih kapljic različne velikosti pri varjenju z močno legiranimi elektrodami (legiranje vara preko obloge) Table 2. Chemical compositions of all weld metals and melted droplets of various sizes in welding with high-alloyed electrodes (weld-metal alloying by the coating) Vzorec / Sample Kemična sestava (%) / chemical composition (%) Velikost kapljice / droplet size Si Cr Ni Nb Var / weld metal 1,04 20,3 8,8 0,63 Rutilno opl. el / Nad / above 4 mm 1,40 20,2 9,4 0,64 Rutile: 2-3 mm 1,18 23,8 9,0 0,46 Pod / less than 2 mm 2,18 34,4 21,7 0,69 Var / weld metal 0,96 20,8 9,5 1,18 Bazično opl. el. / Nad / above 4 mm 0,76 20,1 8,4 0,61 Basic: 2-3 mm 1,12 22,0 8,4 0,68 Pod / less than 2 mm 2,48 40,4 15,9 3,04 Slika 5. Mikrostruktura kapljice (nad 2 mm) pri varjenju z bazično oplaščeno elektrodo; temne pike so bogate z niobom - pov. 50x Figure 5. Droplet microstructure (above 2 mm) in welding with basic electrode; dark spots are rich in niobium. x50 Slika 6. Mikrostruktura kapljice (pod 2 mm) pri varjenju z rutilno kislo opla-ščeno elektrodo; temne pike so dezoksidacijski vključki - pov. 50x. Figure 6. Droplet microstructure (below 2 mm) in welding with rutile-acid electrode; dark spots are deoxidation inclusions. x50 Slika 7. Mikrostruktura zelo drobne kapljice (pod 2 mm) pri varjenju z rutilno kislo oplaščeno elektrodo; svetla polja so bogata s kromom, temnejša pa z nikljem - pov. 50x. Figure 7. Microstructure of very fine droplet (below 2 mm) in welding with rutile-acid electrode; light spots are rich in chromium and darker spots in nickel. x50 Sklepi Pri varjenju z oplaščenimi elektrodami sestava elektrodne obloge odločilno vpliva na varilno tehnične lastnosti elektrode. Z rutilno kislimi elektrodami lahko varimo z izmeničnim tokom in enosmernim tokom na minus pol. Oblok je zelo dobro ioniziran, zato je varjenje stabilno, odtaljevanje kapljic pa fino kapljičasto z zelo malo kratkih stikov (pod 2 %). Pri bazično oplašče-nih elektrodah pa je oblok slabše ioniziran, zato moramo z njimi variti z enosmernim tokom na plus pod. Odtaljevanje kapljic pa je grobo kapljičasto s pogostimi kratkimi stiki (preko 5 %). Preko elektrodne obloge pa lahko tudi le-giramo in dezoksidiramo navar. Pri močno legiranih oplaščenih elektrodah je odtaljevanje bolj grobo kapljičasto, še posebno, če je oplaščenje elektrode bazično. Zanimivo je, da legirni in dezoksidacijski kovinski dodatki v elektrodni oblogi legirajo in dezoksidirajo že kapljice, ki se odtalju-jejo od nelegirane žice. To pomeni, da večji del procesov legiranja in dezoksidacije med varjenjem poteče že na stopnji kapljice (preko 90 %). Odstopanja so le pri legiranju in dezoksidaciji vara s silicijem in niobom pri varjenju z rutilno kislo oplaščenimi elektrodami, ker niob pri visokih temperaturah obloka močno reducira SiO2 v oplaščenju ter povzroči visok prigor Si v kapljici. Na stopnji kopeli vara pa silicij reducira produkte dezoksidacije (predvsem Nb2O5), kar ima za posledico znižanje silicija in zvišanje nioba v navaru. Manjši del legirnih in dezoksidacijskih dodatkov pa legira navar preko zelo drobnih kapljic, ki nastajajo z zlivanjem. Zelo drobne kapljice so zato močno legirane in nehomogene, velike kapljice pa tako po mikrostrukturi, kot tudi kemični sestavi podobne sestavi varov. Prednost bazičnega oplaščenja je intenzivnejše legiranje in dezoksidacija vara. Izgube legirnih dodatkov so manjše. Hiba pa je slabša ionizacija obloka, zato z njimi lahko kvalitetno varimo le z enosmernim tokom na plus pol. Summary Welding of high-alloy steels with covered electrodes In welding with covered electrodes, the composition of an electrode coating has a decisive influence on technical features of the electrode. Rutile-acid electrodes permit welding with alternating current and direct current negative. The arc obtained is well ionised; therefore, welding is sta- ble and melting-off proceeds in fine droplets with very few short circuits (below 2 %). With basic covered electrodes the ionization of the arc is poorer; therefore, welding should be carried out with direct current positive. Melting-off proceeds in coarse drops with frequent short circuits (above 5 %), (see Figures 1 and 2). By means of the electrode coating a surfacing weld may be alloyed and deoxidized. With high-alloy covered electrodes melting-off proceeds in coarse drops, particularly if the electrode coating is basic. It is interesting that alloying and deoxidizing metal additions to the electrode coating produce alloying and deoxidization of the droplets melting off from an unalloyed wire. This means that the major part of alloying and deoxidation processes during welding occur at the stage of droplets (over 90 %) (see Tables 1 and 2, and Figures 3 through 6). There are some deviations only in case of alloying and deoxidation of a weld metal with silicon and niobium in welding with a rutile-acid electrodes because niobium at high arc temperatures strongly reduces SiO2 in the coating and produces a high pick-up of Si in a droplet. At the stage of a weld pool, silicon, however, will reduce products of deoxidation (particularly Nb2O5), which will result in silicon reduction and an increase in nio- bium in the surfacing weld (see Tables 1 and 2). A minor portion of the alloying and deoxidizing additions, however, will alloy the surfacing weld via very fine droplets produced by fusion (see Figure 7). Consequently, the fine droplets are strongly alloyed and non-homogeneous whereas coarser droplets are similar, in terms of microstructure and chemical composition, to the weld metal (see Figures 3 through 6, Tables 1 and 2). An advantage of the basic coating consists in more intense alloying and deoxidation of the weld metal. Losses of the alloying additions are small. Its disadvantage, however, is poorer ionization. Consequently, quality welding requires the use of direct current positive. Viri [1] Kejžar, R., Kralj, V., Rehfeldt, D. (1991): Analiza obloka z analizatorjem, Hannover AH-7. Poročilo ZRMK. Ljubljana, 1991. [2] Kejžar, U., Kejžar, R. (2001): Izpopol- njevanje programske opreme za opazovanje električnih parametrov varjenja. Poročilo o delu. Fakulteta za strojništvo Univerze v Ljubljani, Ljubljana, 2001. [3] Becken (1970): Werkstoffübergang bei Schweisselektvoden. Schweissen und Schneiden 22. Düsseldorf, 11, str. 478/479. [4] [5] [6] Kejžar, R. (1975): Vpliv dezoksidantov na vsebnost kisika v čistem varu in izkoristek Cr iz plašča pri elektroob-ločnem varjenju. Železarski zbornik 9. Jesenice, 1, str. 19/27. Kosec, L., Kejžar, R., Ralič, B. (1974): Mehanizem legiranja varov - analiza produktov varjenja. Poročilo Metalurškega inštituta. Ljubljana, 1974. Evohin, A.A. (1965): Kinctika metallurgi-českih processov dugovoj svarki. Ma-šinostroenie, Moskva. Določitev meje T/J z analizo stabilnih izotopov S13C in 818O (Krim, Slovenija) Determination of T/J boundary by 813C and 818O stable isotope analysis (Krim Mountain, Slovenia) Miloš Miler 1, Jernej Pavšič 2, Matej Dolenec 3 1 Hribi 2, 1291 Škofljica, Slovenija; E-mail: mmiler@email.si 2 Univerza v Ljubljani, Naravoslovnotehniška fakulteta, Oddelek za geologijo, Privoz 11, 1000 Ljubljana, Slovenija; E-mail: jernej.pavsic@ntf.uni-lj.si 3 Univerza v Ljubljani, Naravoslovnotehniška fakulteta, Oddelek za geologijo, Aškerčeva cesta 12, 1000 Ljubljana, Slovenija; E-mail: matej.dolenec@s5.net Received: June 21, 2007 Accepted: October 23, 2007 Izvleček: Izotopske analize ogljika in kisika v dolomitih triasne in jurske starosti iz profilov Žvencelj-Novi zavodi in Tresenk-Rupendol na območju Krimskega hribovja, so bile preliminarne, izvedene z namenom določitve meje med triasom in juro. Zaradi neprekinjene sedimentacije karbonatov na prehodu iz triasa v juro in pomanjkanja fosilnih ostankov meja ni bila natančno določena. Predpostavljena je bila tam, kjer med zrnatim dolomitom glavnega dolomita v loferskem razvoju ni več laminiranega dolomita. Za prehod iz triasa v juro je značilna negativna ogljikova anomalija. Ta je verjetno posledica zgornjetriasne regresije morja. Na zgornjetriasno regresijo kažejo tudi vedno pogostejše dolomitne breče v zgornjem delu zgornjetriasnih plasti. Za spodnjeliasne plasti so značilne povišane vrednosti 513C, ki sovpadajo z nenadno transgresijo morja. Na podlagi rezultatov izotopskih analiz ogljika in kisika je bila meja med triasom in juro natančneje postavljena med črnimi dolomitnimi brečami zgornjetriasne starosti in svetlosivimi zrnatimi dolomiti spodnjeliasne starosti. Abstract: Carbon and oxygen stable isotope analyses of Triassic and Jurassic dolomites from Žvencelj-Novi zavodi and Tresenk-Rupendol sections on Krim Mountain area, were preliminary and were carried out with the purpose of determining T/J boundary. Due to lack of fossil remains and continuous carbonate sedimentation during T/J transition, the exact position of T/J boundary has not been defined yet. It was presumed in coarse-grained Main dolomite in which intermediate beds of laminated dolomites are no longer present. The T/J transition is characterised by negative excursion in 513C. The carbon isotope variability is probably a consequence of Upper Triassic marine regression which is also indicated by more frequently appearing beds of dolomitic breccias in the upper part of Upper Triassic. Fol- lowing positive shift in 513C values is characteristic of Lower Liassic beds and is consistent with sudden marine transgression. Based on results of carbon and oxygen isotope analyses the T/J boundary was more accurately placed between Upper Triassic black dolomitic breccias and Lower Liassic light grey coarse-grained dolomites. Ključne besede: meja T/J, dolomiti, stabilni izotopi ogljika in kisika, Dinarska karbonatna platforma, Krim Key words: T/J boundary, dolomites, carbon and oxygen stable isotopes, Dinaric Carbonate Platform, Krim Mountain Uvod Konec triasa je prišlo do enega največjih množičnih izumrtij, ki po svojem obsegu preseže celo izumrtje ob koncu krede (McRoberts et al., 1997). Pri tem je izumrlo nekaj več kot polovica vseh rodov morskih organizmov. Različni avtorji navajajo različne razloge za izumrtje, kot so zmanjšana bioprodukcija in akumulacija C12 v rezervoarju ogljika (Kump & Arthur, 1999), povečanje količine CO2 v atmosferi zaradi vulkanizma (Kump & Arthur, 1999), sproščanje metana iz metanovih hidratov kot posledica vulkanizma in sledeče spremembe okolja, ki so vplivale na organizme (Palfy et al., 2001), zmanjšanje morskih habitatov zaradi regresije morja in širjenje anoksične vode med sledečo transgresijo (Hallam, 1981) ter prekinitev morske in kopenske prehranjevalne verige zaradi znižanja primarne produkcije (McRoberts et al., 1995). Verjetno pa je šlo za kombinacijo naštetih dogodkov. Raziskave meje T/J na območju avstrijskih Severnih apneniških Alp (McRoberts et al., 1997; Krystyn et al., 2005) in Csövar na Madžarskem (Palfy et al., 2001) kažejo, da je za prehod iz triasa v juro značilna negativna 513C anomalija anorganskega in organskega ogljika. Veliko množičnih izumrtij je povezanih z negativno 513C anomalijo in bolj ali manj vzporedno anomalijo 518O. To pomeni, da so povezana tudi s spremembami v globalnem ogljikovem ciklu (Palfy et al., 2001). Negativna 513C anomalija je posledica zgornjetriasne regresije morja, pri kateri je prišlo do povečanega dotoka meteorne vode in oksidacije organske snovi v morju (McRoberts et al., 1997; Palfy et al., 2001). Izotopska sestava kisika v diagenet-sko nespremenjenih karbonatih pa lahko odraža izotopsko sestavo in temperaturo morske vode (Schräg et al., 1995). Slika 1. Geografski položaj profilov Žvencelj-Novi zavodi (1) in Tresenk-Ru-pendol (2) na območju Krima Figure 1. Geographic location of Žvencelj-Novi zavodi (1) and Tresenk-Ru-pendol (2) sections (Krim Mountain, Slovenia) Geološka zgradba in paleogeografija Za potrebe analize izotopske sestave kisika in ogljika v karbonatih na meji T/J so bile vzorčevane kamnine v profilih Žvencelj-Novi zavodi in Tresenk-Rupendol. Profila sta na območju Krimskega hribovja in sicer vzhodno ter severozahodno od Krima (slika 1). Krimsko hribovje leži v severnem delu Zunanjih Dinaridov, ki so v triasu in juri pripadali Dinarski karbonatni platformi. Na območju Krimskega hribovja je na prehodu iz triasa v juro potekala neprekinjena karbonatna sedimentacija (Plenic ar, 1970). Zaradi postopne litostratigrafske meje in odsotnosti fosilnih ostankov meja med zgornjetriasnimi in spodnjeliasnimi plastmi ni bila biostratigrafsko določena. Po Pleničarju (1970) in Buserju (1986) je meja postavljena tam, kjer med zrnatim dolomitom ni več laminiranega dolomita oziroma tam, kjer se pojavljajo sive do-lomitne breče z zrnatim dolomitnim vezi- vom in ostrorobimi klasti laminiranega dolomita. Po Novaku (2003) pa je meja T/J v litološkem pogledu postavljena v pas, kjer se zaključi loferska sedimentacija, paleon-tološko pa po izumrtju megalodontid. Zgornjetriasne plasti predstavlja glavni dolomit v loferskem razvoju (slika 2). Gre za menjavanje sivega do svetlosivega zrnatega dolomita, sivega do temnosivega stromatolitnega dolomikrita, ki ponekod navzgor prehaja v siv onkodolomikrospa-rit in temnosivih do črnih dolomitnih breč s svetlosivimi klasti. Siv in svetlosiv zrnat dolomit, ki ponekod vsebuje megalodonti-dne školjke, predstavlja člen C loferske ci-kloteme in je nastal v podplimskem okolju. Siv in temnosiv stromatoliten dolomikrit s horizontom sivega onkodolomikrosparita, ki ga tvorijo ostanki onkoidov tipa »Spha-erocodium bornemanni«, predstavlja člen B, ki je nastal v medplimskem okolju. Te-mnosive do črne dolomitne breče pa so nastale v nadplimskem okolju in predstavlja- jo člen A. Menjavanje teh členov je posledica pogrezanja šelfa, evstazije in produkcije karbonata. Dolomitnih breč člena A je navzgor vedno več, kar kaže na postopno regresijo morja (McRoberts et al., 1997; Krystyn et al., 2005). Večje debeline breč v skrajnem zgornjem delu zgornjega triasa so lahko tudi posledica močnejše sinsedi -mentne tektonike. V spodnjem delu spodnjeliasnih plasti je menjavanje sive do črne dolomitne breče s klasti zrnatega in laminiranega dolomita, s sivim do svetlosivim zrnatim dolomitom. Sive do črne dolomitne breče so verjetno nastale še v plitvem okolju pod vplivom sinsedimentne tektonike (McRoberts et al., 1997). Zaradi poglabljanja morja oz. spodnjeliasne transgresije (Hallam, 1997) stromatolitne lamine niso več nastajale in so zato v sivem zrnatem dolomitu odsotne. V zgornjem delu spodnjeliasnih plasti pa se že pojavlja svetlosiv mikriten apnenec. Materiali in metode Analiziranih je bilo 16 vzorcev iz profilov Žvencelj-Novi zavodi in Tresenk-Rupen-dol. Uporabljeni so bili sveži neprepereli vzorci dolomitov. Vzorci dolomitov so bili zmleti v homogen prah. Vsak izmed 16 vzorcev je bil razdeljen na 4 manjše 8 miligramske vzorce, ki so bili odtehtani s tehtnico Mettler Toledo AE240. Pri reakciji 100 % fosforne kisline (H3PO4) s karbonatom pri 50 °C se je tvoril plin CO2, ki je bil nato analiziran z masnim spektrometrom Varian MAT 250. Vrednosti razultatov so bile normalizirane glede na standarda IAEA-CO-1 (8* po 4 mg) z 513C vrednostjo +2,48 %o in 518OVPDB vrednostjo -2,44 %o ter NBS-19 (8* po4 mg) z 513C vrednostjo +1,95 %o in 518OVPDB vrednostjo -2,20 %o. Vsi vzorci so bili analizirani na Inštitutu Jožef Štefan v Ljubljani. Slika 2. Litostratigrafski stolpec zgornjetriasnih in spodnjeliasnih plasti na območju Krima Figure 2. Lithostratigraphic column of Upper Triassic and Lower Liassic beds in Krim Mountain area Rezultati raziskav Izotopske analize ogljika in kisika so bile preliminarne, opravljene z namenom natančnejše določitve postopne meje med triasom in juro zaradi pomanjkanja fosilnih ostankov v dolomitih. Izotopske sestave ogljika in kisika iz profilov Žvencelj-Novi zavodi in Tre-senk-Rupendol so navedene v tabeli 1 in 2 ter grafično prikazane na sliki 3. Vrednosti 513C v profilu Žvencelj-Novi zavodi (tabela 1) se gibljejo med +0,62 %o in +1,82 %o, vrednosti 518O pa med -4,15 %0 in +0,67 %o. V profilu Tresenk-Rupendol (tabela 2) pa so vrednosti 513C med +1,04 %o in +2,72 %o ter 518O med -5,28 %0 in +0,64 %o. Najvišja vrednost 513C je v obeh profilih dosežena v zgornjetriasnem sivem stro-matolitnem in svetlosivem drobno in sre-dnjezrnatem dolomitu (vzorci IA0, IA16-2 in IA16-1), ki se pojavlja med stromatoli-tnim. Minimalna vrednost je pri obeh profilih dosežena v debeli črni in temnosivi Tabela 1. Izotopska sestava ogljika in kisika v dolomitih iz profila Žvencelj-Novi zavodi Table 1. Isotopic composition of carbon and oxygen in dolomites from Žvencelj-Novi zavodi section Vzorec-Sample 618O std. 613C std. IA0 -0,16 0,00 1,82 0,04 IA1 -1,36 0,03 0,62 0,08 IA2 -4,15 0,06 1,22 0,03 IA3 0,67 0,07 1,75 0,07 IA3a -2,70 0,06 1,00 0,08 IA3b -0,68 0,03 1,19 0,01 Tabela 2. Izotopska sestava ogljika in kisika v dolomitih iz profila Tresenk-Rupendol Table 2. Isotopic composition of carbon and oxygen in dolomites from Tresenk-Rupendol section Vzorec-Sample 618O std. 613C std. IA16-2, IA16-1 0,45 0,12 2,72 0,09 IA15 -0,40 0,15 1,04 0,14 IA13 -5,28 0,04 1,55 0,07 IA12 -0,46 0,08 1,36 0,12 IA11 -2,63 0,01 2,12 0,04 IA9 0,64 0,04 1,30 0,05 IA8 0,53 0,02 1,72 0,05 IA7 -0,57 0,14 1,48 0,13 IA5 0,20 0,03 1,21 0,05 STAROST AGE . (л 3« LITOLOGUA UTHOLOGY VZOREC SAMPLE BARVA COLOUR zvenceu - ),s L itä г novi zavodi 51Ъ(*о) ■* -2 0 tresenk l'tH i г з rupendol б1ЪСЧ -4-2 0 2 JURA-JURASSIC SPODMJI LIAS-LOWER LIASSIC /' i 1 / ss { ( i ■ ', ' ■ —^ ss-ts ts * »й t/ ss 8 cn t / / ms б-ss / / lv ■ s-ts / • / • га ■ s / / lajb. 149 s / / 1 ia3a, la31' s & а/а л/ ia3 ts-ć / / LA12 ss 1а2.1а1э ss-e TRIAS-TRIASSIC ■z. < P*Ì ÜS II л v- / А а / л, / л Ь ( t> lai, lai 5 č / / У / У p iao, ia16-1, ia16-2 ' ss /4 л./ fr <7 А/ ts s Slika 3. Litostratigrafski stolpec in izotopska sestava ogljika in kisika v dolomitih raziskanih profilov Figure 3. Lithostratigraphic column and isotopic composition of carbon and oxygen in dolomites from studied sections Legenda k sliki 2 in 3 1 - apnenec, 2 - dolomit, 3 - dolomitna breča s svetlosivimi klasti, 4 - dolomitna breča s črnimi klasti, 5 - bituminozni dolomit, 6 - stromatolitni dolomit, 7 - dolomit z megalodontidami, 8 - onkoidni dolomit, 9 - onkoidi, 10 - stromatoliti, 11 - megalodontidne školjke, 12 - vzporedna laminacija, 13 - siva, 14 - svetlo siva, 15 - temno siva, 16 - črna, 17 - bela Explanation of Figure 2 and 3 1 - limestone, 2 - dolomite, 3 - dolomitic breccia with light grey clasts, 4 - dolomitic breccia with black clasts, 5 - bituminous dolomite, 6 - stromatolitic dolomite, 7 - dolomite with Megalodontids, 8 - oncoidal dolomite, 9 - oncoids, 10 - stromatolites, 11 - Megalodontids, 12 - parallel lamination, 13 - grey, 14 - light grey, 15 - dark grey, 16 - black, 17 - white dolomitni breči (vzorca IA1 in IA15), ki predstavlja skrajni zgornji del zgornjega triasa in je verjetno nastala v času viška zgornjetriasne regresije morja. Prvo zvišanje vrednosti 513C v svetlosivih zrnatih dolomitih (vzorca IA2 in IA13) sovpada z začetkom spodnjeliasnega zvišanja gladine morja oziroma transgresije. Meja med triasom in juro je bila tako postavljena med črnimi dolomitnimi brečami in svetlosivim zrnatim dolomitom (slika 3). Vrednost 518O v vzorcih IA1 in IA15, vzporedna minimalni vrednosti 513C, je relativno visoka in bi lahko sovpadala s povišano temperaturo v času viška regresije. Minimalna vrednost 518O v vzorcih IA2 in IA13 pa poteka vzporedno s prvim povišanjem vrednosti 513C in sovpada z znižanjem temperature oziroma spremembo kemizma morske vode (pornih voda) pri spodnjeliasni transgresiji morja. Nadaljna nihanja vrednosti 513C in 518O predstavljajo manjša nihanja gladine morja med napredujočo spodnjeliasno transgresijo. Med analiziranimi različki dolomitov prevladujejo zrnati dolomiti in vezivo dolo-mitnih breč ter redki mikritni in laminirani mikritni dolomiti. Zrnati dolomiti so nastali s poznodiagenetsko dolomitizacijo, laminirani mikritni dolomiti pa imajo ohranjeno prvotno strukturo kamnine in so nastali z zgodnjediagenetsko dolomitizacijo. Razprava Rezultati izotopskih analiz ogljika in lito-loških raziskav kažejo, da je debela črna in temnosiva dolomitna breča nastala pod vplivom močne sinsedimentne tektonike verjetno v času viška zgornjetriasne regresije morja, ob kateri je prišlo do povečanega dotoka meteornih voda, in predstavlja skrajni zgornji del zgornjega triasa. Sve-tlosivi zrnati dolomiti nad brečo so nastali v nekoliko globlji vodi med začetkom spo-dnjeliasne transgresije morja. Podatki o izotopski sestavi kisika kažejo, da je bila v zgornjem delu zgornjega triasa, v času viška regresije, temperatura vode verjetno nekoliko povišana. Nasprotno se je v spodnjem delu spodnjega liasa, zaradi napredujoče transgresije, temperatura vode znižala oziroma je prišlo do spremembe kemizma morske vode (pornih voda). Za mejo T/J je značilna negativna 513C anomalija, ki je posledica povečanega dotoka meteorne vode in oksidacije morske organske snovi med zgornjetriasno regresijo morja. Zaradi regresije je prišlo do su-baerske oksidacije organske snovi, pri čemer se je C12 vezal v CO2 in se uravnotežil z oceansko vodo. Pri tem se je rezervoar ogljika v oceanski vodi obogatil z lažjim izotopom ogljika (Dolenec et al., 1998; Palfy et al., 2001). Pri transgresiji morja pa se je zgodilo ravno obratno. Oceanska voda se je relativno obogatila s težjim ogljikovim izotopom. Poleg tega pa zaradi poglabljanja morja stromatolitne lamine med spodnjeliasnimi zrnatimi dolomiti niso več nastajale. Zaradi pomanjkanja oziroma odsotnosti fosilnih ostankov meja med triasom in juro ni bila paleontološko utemeljena. Naše raziskave so izhajale iz stare predpostavke, da je meja med triasom in juro postavljena tam, kjer se med zrnatim dolomitom lami-niran dolomit ne pojavlja več (Pleničar, 1970; Buser, 1986). V litološkem pogledu je meja T/J postavljena v pas, kjer se zaključi loferska sedimentacija, paleonto-loško pa po izumrtju megalodontid (Novak, 2003). Samo na podlagi litoloških in sedimentoloških značilnosti ne moremo določiti natančnega položaja meje, lahko pa vsaj približno opredelimo interval, v katerem se meja nahaja. Vzorci so bili odvzeti v intervalu od zrnatega dolomita, ki leži pod laminiranim dolomitom do prvega pojava mikritnega apnenca, nad katerim leži ooidni apnenec, ki je biostratigrafsko dokazano srednjeliasne starosti. Obravnavano zaporedje kamnin tako skoraj zagotovo obsega skrajni zgornji del retija in spodnji del spodnjega liasa ter s tem tudi mejo T/J. Primerjava obravnavanih plasti z zgornje-triasnimi in spodnjeliasnimi plastmi Severnih Apneniških Alp (McRoberts et al., 1997; Krystyn et al., 2005) je pokazala, da so v Severnih Apneniških Alpah v nori-ju nastajali glavni dolomiti in dachsteinski apnenci v laguni, ki so jo pričeli v zgornjem retiju prekrivati bioklastični apnenci in la-porovci, medtem ko se je na obravnavanem ozemlju sedimentacija glavnega dolomita zaključila s temnosivimi do črnimi sinse-dimentnimi brečami večjih debelin. Zaradi napredujoče sedimentacije klastičnih kamnin se je karbonatna platforma skrčila in delno okopnila. Sedimentacija pa se je nadaljevala v bazenskih predelih, kjer so nastala t.i. »znotrajplatformska« medplimska okolja z značilno favno megalodontidnih školjk in loferskim faciesom (McRoberts et al., 1997). Med retijem in spodnjim lia-som so se ob začetku transgresije odložile klastične in karbonatno klastične kamnine mejnih plasti (muljevci, meljevci in lapor-nati apnenci) brez značilnih fosilov. Nad mejnimi plastmi je več horizontov z zaobljenimi klasti apnencev, ki vsebujejo zgor-njetriasne foraminifere (McRoberts et al., 1997). Te horizonte bi lahko primerjali s temnosivimi do črnimi dolomitnimi brečami obravnavanega ozemlja, ki vsebujejo klaste zrnatega in laminiranega zgornjetri-asnega dolomita. V plitvem podplimskem okolju pa so nastali ooidni apnenci z amo-niti, ki kažejo na hettangijsko starost. Ker so bili vzorčevani predvsem pozno-diagenetski dolomiti, obstaja verjetnost, da so primarni izotopski signal zabrisale poznodiagenetske spremembe. Dobljeni izotopski signal je tako lahko posledica izmenjave z izotopsko lažjo porno vodo pri poznodiagenetskih procesih. Poznodiage-netski dolomiti so glede na zgodnjediage-netske običajno obogateni z lahkima izotopoma ogljika in kisika, vendar pa imajo nekateri norijsko-retijski poznodiagenet-ski dolomiti podobno izotopsko sestavo kot zgodnjediagenetski, kar pomeni, da se temperatura in izotopska sestava raztopin, ki so povzročile poznodiagenetsko dolo-mitizacijo, nista bistveno razlikovali od morske vode, v kateri je nastal zgodnjediagenetski dolomit (Ügorelec et al., 1999). Ker je do poznodiagenetske dolomitizacije glavnega dolomita prišlo še v času norija in retija (ügorelec & Rothe, 1993) in se je poznodiagenetska dolomitizacija spo-dnjeliasnih dolomitov izvršila v spodnjem liasu, so imele porne raztopine, ki so časovno različni dolomitizaciji povzročile, verjetno različno izotopsko sestavo. Zato je primerjava rezultatov izotopskih analiz poznodiagenetskih dolomitov zgornjetriasne in spodnjeliasne starosti smiselna. Da je prišlo do popolne dolomitizacije glavnega dolomita v času zgornjega triasa, dokazujejo tudi klasti zrnatih in laminiranih dolomitov v liasnih brečah. Za kvalitetnejšo interpretacijo rezultatov izotopske analize bi bilo potrebno analizirati večje število vzorcev, odvzetih v manjših medsebojnih intervalih in obravnavati večji profil. Sklepi Na območju Krimskega hribovja so v času zgornjega triasa na Dinarski karbonatni platformi nastajali glavni dolomiti v lofer-skem razvoju z redkimi ohranjenimi fosilnimi ostanki. V nadplimskem okolju so nastale dolomitne breče, v medplimskem okolju zgodnjediagenetski stromatolitni dolomiti in v podplimskem okolju zrnati dolomiti, ki so nastali s poznodiagenetsko dolomitizacijo. V času spodnjega liasa pa so nastajale črne in svetlosive dolomitne breče ter sivi zrnati dolomiti brez vmesnih plasti laminiranih dolomitov. asna starost) in svetlosivimi zrnatimi dolomiti (spodnjeliasna starost). Za natančnejšo in bolj zanesljivo določitev meje pa bi bile vsekakor potrebne podrobnejše in obširnejše izotopske analize s pogostejšim vzorčevanjem. Na vrednosti 513C in 518O v karbonatih vpliva izotopska sestava organske snovi v morju med sedimentacijo in kasnejše diagenetske spremembe (Pezdič, 1999). Diagenetske spremembe, ki lahko povzročijo vzporedne negativne anomalije 518O in 513C, vplivajo predvsem na vrednosti 513C, (Palfy et al., 2001). Litološka in izotopska analiza zgornjetri-asnih kamnin sta pokazali, da je v času zgornjega triasa prišlo do napredujoče regresije morja, ki je dosegla svoj višek konec zgornjega triasa. Z začetkom spodnjega liasa pa se je pričelo poglabljanje morja oziroma transgresija, na kar kaže tudi odsotnost stromatolitnih dolomitov med zrnatimi dolomiti. Na podlagi litoloških značilnosti in rezultatov izotopskih analiz smo sklepali, da poteka meja T/J, na območju Krima, med črnimi dolomitnimi brečami (zgornjetri- Pri poznodiagenetskih dolomitih, ki imajo podobno izotopsko sestavo kot zgodnje-diagenetski, je bila izotopska sestava raztopin, ki so povzročile poznodiagenetsko dolomitizacijo, verjetno podobna izotop-ski sestavi morske vode. Poleg tega je do popolne dolomitizacije glavnega dolomita prišlo še v času norija in retija (Ogorelec & Rothe, 1993; Novak, 2003), zato lahko s primerjavo izotopske sestave ogljika in kisika v poznodiagenetskih dolomitih zgor-njetriasne in spodnjeliasne starosti dobimo zadovoljive rezultate, ki so uporabni pri določitvi meje T/J. Summary Determination of T/J boundary by 513C and 518O stable isotope analysis (Krim Mountain, Slovenia) One of the most extensive mass extinctions, which caused extinction of more than 50 % of marine genera (McRoberts et al., 1997), took place at the end of Triassic period. There are different hypotheses explaining this extinction, but the most possible reason is a decrease in primary productivity and a reduction of marine habitats due to marine regression. Dolomites from two locations on Krim Mountain area (Figure 1) were sampled to define Triassic-Jurassic boundary. Krim Mountain area belongs to northern part of External Dinarides. During Triassic and Jurassic period carbonates of External Dinarides were deposited on Dinaric Carbonate Platform. The transition from Triassic to Jurassic was characterized by continuous carbonate sedimentation. Dolomites that exhibit cyclic bedded, supra to subtidal ''Lofer facies'' (Main dolomite) were deposited during Upper Triassic. Characteristic of Upper Triassic beds is an alternation of grey to light grey coarsegrained dolomites with rare megalodontid bivalves, grey and dark grey stromatolitic dolomicrite, grey oncodolomicrosparite with Sphaerocodium bornemanni and dark grey to black dolomitic breccias (Figure 2). Beds of supratidal dolomitic breccias appear more and more frequently upwards in the upper part of Upper Triassic, which indicates gradual sea-level fall (McRoberts et al., 1997; Krystyn et al., 2005). Alternation of grey to black dolomitic bre- ccias that contain clasts of coarse-grained and laminated dolomites with grey to light grey coarse-grained dolomites without intermediate stromatolitic laminae, in the lower part of Lower Liassic beds, indicates sea-level rise. Coarse-grained dolomites and dolomitic breccias are overlain by light grey micritic limestones in the upper part of Lower Liassic beds. 16 samples of non-degraded dolomites from Žvencelj-Novi zavodi and Tresenk-Rupendol sections were analysed. Samples were powdered and homogenized and treated with phosphoric acid. Isotopic composition of obtained CO2 was measured on Varian MAT 250 mass spectrometer. Data were normalized according to international standards. Oxygen and carbon isotope compositions are presented in Tables 1 and 2 and shown in Figure 3. Stable isotope studies of Triassic-Juras-sic boundary in the Northern Calcareous Alps, Austria (McRoberts et al., 1997; Krystyn et al., 2005) and Csövar section, Hungary (Palfy et al., 2001), show negative 513C anomaly in boundary beds as a consequence of meteoric water influx and oxidation of organic matter during Upper Triassic marine regression (McRoberts et al., 1997; Palfy et al., 2001). 513C values in dolomites from sections Žvencelj-Novi zavodi and Tresenk-Rupen-dol range from +0,62 %o to +2,72 %o and 518O from -5,28 %o to +0,67 %o. Positive excursion in 513C was recorded in Upper Triassic grey stromatolitic and light grey grainy dolomites. It is followed by prono-uced negative 513C anomaly in black and dark grey dolomitic breccias, coinciding with sea-level fall. Following positive 513C anomaly within light grey coarse-grained dolomites may reflect the beginning of the Lower Liassic sea-level rise. Based on li-thologic features and results of oxygen and carbon isotope analyses, the Triassic-Juras-sic boundary was more accurately defined between black dolomitic breccias and light grey coarse-grained dolomites (Figure 3). The 518O variability could reflect temperature changes and changes in isotopic composition of seawater or pore fluids during sea-level fluctuations. Due to lack of fossil remains, the Triassic-Jurassic boundary was not paleontological-ly documented. Thus, our researches were based on old presumption that Triassic-Ju-rassic boundary lies within coarse-grained dolomite in which intermediate beds of laminated dolomites are no longer present (Pleničar, 1970; Buser, 1986). The analysed dolomites were mostly late diagenetic therefore the diagenetic alterations could have significant influence on 513C and 518O values. Late diagenetic dolomites are usually depleted in heavy carbon and oxygen isotopes compared to early diagenetic dolomites. However, some late diagenetic dolomites have isotopic com- position similar to that of early diagenetic dolomites, which means that temperature and isotopic composition of pore fluids, that caused late diagenetic dolomitization were similar to those of sea-water, in which early diagenetic dolomites were deposited (ogorelec et al., 1999). Upper Triassic carbonates were completely dolomitized by the end of Triassic (ogorelec & Rothe, 1993), which is proved by Liassic breccias containing clasts of coarse-grained and laminated dolomites, and late diagenetic dolomitization of Lower Liassic carbonates occurred within Lower Liassic, it can be assumed that isotopic composition of pore fluids that caused do-lomitization of Upper Triassic carbonates probably differs from isotopic composition of pore fluids that caused dolomitization of Lower Liassic carbonates. Thus, it can be concluded that results of isotopic analyses of late diagenetic dolomites can be used for determination of Triassic-Jurassic boundary. For more precise determination of the Tri-assic-Jurassic boundary, more detailed is-otopic and lithologic analyses with more frequent sampling should be carried out Zahvala Avtorji se zahvaljujemo Institutu Jožef Stefan, predvsem dr. Sonji Lojen, za opravljene izotopske analize ter tehničnim sodelavcem Oddelka za geologijo Nara-voslovnotehniške fakultete za pomoč pri pripravi vzorcev. Viri Buser, S. (1986): Osnovna geološka karta SFRJ 1:100.000. Tolmač listov Tolmin in Videm. Zvezni geološki zavod, Beograd, pp. 1-103. Dolenec, T, Buser, S., Dolenec, M. (1998): The Permian-Triassic boundary in the Karavanke Mountains (Slovenia): Stable isotope variations in the boundary carbonate rocks of the Košutnik Creek and Brsnina section = Perm-sko-triasna meja v Karavankah: variabilnost izotopske sestave v karbonatih Košutnikovega potoka in Brsnine. Geologija.; Vol. 41, pp. 17-27. Hallam, A. (1981): The end-Triassic bivalve extinction event. Palaeogeography, Palaeoclimatology, Palaeoecology.; Vol. 35, pp. 1-44. Hallam, A. (1997): Estimates of the amount and rate of sea-level change across the Rhaetian-Hettangian and Pliens-bachian-Toarcian boundaries (latest Triassic to early Jurassic). Journal of the Geological Society.; Vol. 154, pp. 733-779. Krystyn, L., Böhm, F., Kürschner, W., Dele-cat, S. (2005): The Triassic-Jurassic boundary in the Northern Calcareous Alps. Field guide.; pp. 1-14. Kump, L. R., Arthur, m. a. (1999): Interpreting carbon-isotope excursions: Carbonates and organic matter. Chemical Geology.; Vol. 161, pp. 181-198. McRoberts, c. A., Newton, c. r. (1995): Selective extinction among end-Triassic European bivalves. Geology.; Vol. 23, pp. 102-104. McRoberts, c. A., Furrer, H., Jones, D. s. (1997): Palaeoenvironmental interpretation of a Triassic-Jurassic boundary section from Western Austria based on palaeoecological and geochemical data. Palaeogeography, Palaeoclima-tology, Palaeoecology.; Vol. 136, pp. 79-95. Novak, M. (2003): Zgornjetriasne in spodnje-jurske plasti na območju Podutika pri Ljubljani = Upper Triassic and Lower Jurassic beds in the Podutik area near Ljubljana (Slovenia). Geologija.; Vol. 46/1, str. 65-74. ogorelec, B., Rothe, P. (1993): Mikrofazies, Diagenese und Geochemie des Dachsteinkalkes und Hauptdolomits in Süd- West- Slowenien. Geologija.; Vol. 35, pp. 81-181. ogorelec, B., Dolenec, T., Pezdič, J. (1999): Izotopska sestava O in C v mezozoj-skih karbonatnih kamninah Slovenije - vpliv faciesa in diageneze = Isotope composition of O and C in Mesozoic carbonate rocks of Slovenia - effect of facies and diagenesis. Geologija.; Vol. 42, pp. 171-205. Palfy, J., Demeny, A., Haas, J., Hetenyi, M., orchard, M. J., veto, I. (2001): Carbon isotope anomaly and other geo-chemical changes at the Triassic-Ju-rassic boundary from a marine section in Hungary. Geology.; Vol. 29/11, pp. 1047-1050. Pezdič, J. (1999): Izotopi in geokemijski procesi. Naravoslovnotehniška fakulteta, Oddelek za geologijo, Ljubljana, 281 str. Pleničar, M. (1970): Osnovna geološka karta SFRJ 1:100.000. Tolmač lista Postoj -na. Zvezni geološki zavod, Beograd, str. 62. schräg, D. P., Depaolo, D. J., Richter, F. M. (1995): Reconstructing past sea surface temperatures: Correcting for diagenesis of bulk marine carbonates. Ge-ochimimica et Cosmochimica Acta.; Vol. 59, pp. 2265-2278. Foraminiferal suborder Robertinina from the Badenian of Kozjansko (Eastern Slovenia) Foraminiferni podred Robertinina iz badenija na Kozjanskem (vzhodna Slovenija) Katarina Oblak 1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Department of Geology, Privoz 11, SI-1000 Ljubljana, Slovenia; E-mail: katarina.oblak@ntf.uni-lj.si Received: September 5, 2007 Accepted: October 18, 2007 Abstract: In this study, two Badenian foraminiferal species of the suborder Robertinina from Kozjansko (Eastern Slovenia) are presented. Both species Ceratobulimina contraria (Reuss) and Hoeglundina elegans (d'Orbigny) occur frequently in samples from the Lower to Upper Badenian (Middle Miocene). The occurrence of C. contraria in the Upper Badenian indicates a wider stratigraphic range for the Central Paratethys than was previously recognized. This species has not been determined from Middle Miocene strata of Slovenia before this work. H. elegans is already known from the Middle Miocene of Slovenia, but in this paper specimens are described, imaged and classified for the first time. Povzetek: V prispevku sta predstavljeni dve badenijski foraminiferni vrsti iz po-dreda Robertinina s Kozjanskega (vzhodna Slovenija). Obe vrsti, Ceratobulimina contraria (Reuss) in Hoeglundina elegans (d'Orbigny), sta številčno zastopani v vzorcih od spodnjega do zgornjega badenija (srednji miocen). Pojav vrste C. contraria v zgornjebadenijskih plasteh kaže na njen širši stratigrafski razpon kot je bil za območje Centralne Paratetide poznan doslej. V srednjemiocenskih sedimentih Slovenije vrsta še ni bila določena. Vrsta H. elegans je iz srednjega miocena Slovenije sicer že poznana, vendar je v prispevku prvič opisana, upodobljena in uvrščena v sistem. Key words: Foraminifera, Robertinina, Badenian, Miocene, Central Paratethys Ključne besede: foraminifere, Robertinina, badenij, miocen, Centralna Paratet-ida 204 Oblak, K. Introduction The suborder Robertinina Loeblich & Tappan , 1984 is the last of twelve suborders described in the foraminiferal classification of Loeblich & Tappan (1987). The suborder is defined by the following characteristics; planispirally to trochospi-rally-enrolled tests, chambers commonly with internal partition and hyaline perforate wall composed of ultrastructurally and optically radiate aragonite (Loeblich & Tappan, 1984). With the exception of the extinct suborder Involutinina, which died out during the Mesozoic, all other hyaline foraminifera have tests formed of calcite. According to the foraminiferal classification of Loeblich and Tappan (1987), the suborder Robertinina includes 48 genera, ranging from the Upper Triassic to Holo-cene. From the Middle Miocene, six genera are recognized globally, and only four have been noted in European sediments: Ceratobulimina Toula, 1915, Lamarckina (Berthelin, 1881), Hoeglundina Brotzen, 1948 and Robertina d'Orbigny, 1846. Due to its relatively low species diversity in the Middle Miocene deposits, the suborder Robertinina represents a less frequent mentioned foraminiferal taxon in the literature. In Slovenia, foraminifera of the suborder Robertinina are poorly represented in sedimentary sequences. In Miocene sediments, only the species Hoeglundina elegans has been identified. It is noted as Hoeglun-dina elegans or Epistomina elegans from the Lower Egerian of the Laško syncline (Dozet et al., 1999), from the Upper Egerian of the Laško syncline (Dozet et al., 1999) and Planina syncline (Petrica et al., 1995, Dozet et al., 1999), from the Lower Badenian of Dravinjske gorice (Ri-JAVEC, 1975), from the Middle Badenian of the Laško syncline (Rijavec, 1976 in 1984) and Planina syncline (Rijavec, 1977), and from the Upper Badenian of the Laško syncline (Rijavec, 1976 in 1984). The species hasn't been described, imaged and classified further in a system previously. The species Ceratobulimina contraria hasn't been determined in any other previous research in Slovenia. In Kozjansko, robertininas were studied from six sections. The investigated area belongs to the Planina syncline, the westernmost margin of the Central Paratethys (Buser, 1977, 1979, Aničić & Juriša 1984, Aničić & Juriša 1985, Aničić et al., 2004). Material and methods Robertininas of Kozjansko were studied from six sections of the Planina syncline; Imenska Gorca, Plohov breg, Javoršica, Sveta Ana and Trobni Dol on the northern flank and Drensko Rebro on the south- ern flank (Oblak, 2006). One hundred and twenty-eight samples of Badenian marl and marly calcarenite were studied. Samples range from the Lower Badenian Lower Lagenidae Zone to the Upper Bade-nian Virgulinella pertusa Zone (Figure 1, Oblak, 2006). 187 species were deter- mined and classified into seven foramin-iferal suborders. The suborder Robertinina is represented by two species: Ceratobu-limina contraria (Reuss) and Hoeglundina elegans (d'Orbigny). Although the preser- vation is poor due to aragonitic composition, the characteristic appearance of both species allows accurate identification of specimens. Results and discussion Taxonomy of Foraminifera (according to Loeblich&Tappan, 1987) Ordo Foraminiferida Eichwald, 1830 Subordo Robertinina Loeblich & Tappan, 1984 Superfamilia Ceratobuliminacea Cushman, 1927 Familia Ceratobuliminidae Cushman, 1927 Subfamilia Ceratobulimininae Cushman, 1927 Genus Ceratobulimina Toula, 1915 Ceratobulimina contraria (Reuss, 1851) (Plate 1, figs. 1-8) 1851 Rotalina contraria - Reuss, 76, Taf. V, Fig. 37a-c. 1969 Ceratobulimina (Ceratobulimina) contraria (Reuss) - Langer, 62, Abb. 12b-c, Taf. 3, Fig. 15. 1975 Ceratobulimina contraria (Reuss) - PoPEscu, 105, pl. XC, Figs. 2a-b. 1982 Ceratobulimina contraria (Reuss) - Dondi & Barbieri, tav. XLIII, Fig. 2. 1987 Ceratobulimina contraria (Reuss) - Loeblich & Tappan, pl. 473, Figs. 9-13. 1995 Ceratobulimina contraria (Reuss) - Yassini & Jones, 142, Figs. 960-961. 1998 Ceratobulimina contraria (Reuss) - Cicha et al., 89, pl. 29, Figs. 9-10. 206 Üblak, K. Plate 1. Ceratobulimina contraria (Reuss, 1851). Fig. 1: Spiral side; J 33, Fig. 2: Spiral side; J 33, Fig. 3: Spiral side; J 33, Fig. 4: Umbilical side; J 33, Fig. 5: Umbilical side; J 33, Fig. 6: Umbilical side; J 27, Fig. 7: Side view; J 33, Fig. 8: Aperture; J 32. Scale bar represents 100 ^m. Tabla 1. Ceratobulimina contraria (Reuss, 1851). Sl. 1: Spiralna stran; J 33, Sl. 2: Spiralna stran; J 33, Sl. 3: Spiralna stran; J 33, Sl. 4: Umbilikalna stran; J 33, Sl. 5: Umbilikalna stran; J 33, Sl. 6: Umbilikalna stran; J 27, Sl. 7: Pogled s strani; J 33, Sl. 8: Ustje; J 32. Merilce predstavlja 100 ^m. Material: Rare to numerous tests from 15 samples (Figure 1). Description: Test consists of trochospi-rally arranged chambers. It is ovate in outline. Spiral side is slightly convex. Sutures are curved on the spiral side and straight on the umbilical side. Umbilicus is deep. Periphery is broadly rounded. Surface is very smooth and finely perforate. Aperture is in a shape of a narrow loop, running vertically along the apertural face. Wall is ara-gonitic (Loeblich & Tappan, 1987). Remark: Preservation of tests is poor. In the study of Grünig (1985), specimens are similar to mine by shape but differ in low slitlike aperture that characterize the genus Ceratocancris. Considering this, the species is cited as Ceratocancris contraria. Size: Test height is 0.38 - 0.45 mm, broadness 0.27 - 0.34 mm and thickness 0.2 mm. Occurrence: The species was first described from the Oligocene of Germany (remark: in 1851, the geological period Oligocene hasn't been assigned yet so these strata were determined as of Eocene age). In Germany, it is known from the Oligocene (Loeblich & Tappan, 1987) and the Middle Miocene (Langer, 1969), in Denmark from the Oligocene (Loeblich & Tappan, 1987) and in Italy from the Upper Oligocene to the Serravallian, maybe also to the Tortonian; it is most common in the Serravallian (Dondi & Barbieri, 1982: identified from samples collected in the Po Valley). The species is extant; it is noted from the South Pacific (Y assini & Jones, 1995). In the Central Paratethys, it appears from the Upper Eocene to the end of the Middle Badenian, its appearance in the Ottnan-gian and Karpatian is not certain (Cicha et al., 1998). In Hungary, it is known from the Lower Egerian (sztràkos, 1979) and in Romania from the Miocene (Popescu, 1975). Familia Epistominidae Wedekind, 1937 Subfamilia Epistomininae Wedekind, 1937 Genus Hoeglundina Brotzen, 1948 Hoeglundina elegans (d'Orbigny, 1826) (Plate 2, Figs. 1-5) 1826 Rotalia (Turbinulina) elegans - d'orbigny, 110. 1959 Epistomina elegans (d'Orbigny) - Dieci, 81, tav. VI, Fig. 31. 1960 Hoeglundina elegans (d'Orbigny) - Barker, 216, pl. 105, Figs. 3-6. 1975 Hoeglundina elegans (d'Orbigny) - Popescu, 106, pl. XC, Figs. 3a-c. 1982 Hoeglundina elegans (d'Orbigny) - Dondi & Barbieri, tav. XLI, Fig. 10. 1985 Hoeglundina elegans (d'Orbigny) - Papp & Schmid, 59, Taf. 49, Fig. 1-6. 1991 Hoeglundina elegans (d'Orbigny) - Cimerman & Langer, 56, pl. 59, Figs. 10-12. 1998 Hoeglundina elegans (d'Orbigny) - Cicha et al., 108, pl. 29, Figs. 19-21. 1998 Hoeglundina elegans (d'Orbigny) - Robertson, 114, pl. 44, Figs. 2a-e. Plate 2. Hoeglundina elegans (d'Orbigny, 1826). Fig. 1: Spiral side; Dr 17, Fig. 2: Spiral side; J 32, Fig. 3: Umbilical side; Dr 17, Fig. 4: Side view; Dr 17, Fig. 5: Side view; J 32. Scale bar represents 100 ^m. Tabla 2. Hoeglundina elegans (d'Orbigny, 1826). Sl. 1: Spiralna stran; Dr 17, Sl. 2: Spiralna stran; J 32, Sl. 3: Umbilikalna stran; Dr 17, Sl. 4: Pogled s strani; Dr 17, Sl. 5: Pogled s strani; J 32. Merilce predstavlja 100 ^m. Material: Rare to numerous tests from 16 samples (Figure 1). Description: Test is trochospiral and biconvex. Sutures are thickened. They are curved backward on the spiral side, and straight and oblique on the umbilical side. Periphery is subacute. Surface is smooth and finely perforate. Slitlike aperture is lat-eromarginal. Wall is aragonitic (Loeblich & Tappan, 1987). Size: Test diameter is 0.42 - 0.52 mm and thickness 0.25 mm. Remark: Preservation of tests is poor. Occurrence: There are no data about the type locality and type level by the first description (d'Orbigny, 1826). In Italy, the species is known from the Middle Eocene to Pleistocene, it is very frequent in the Upper Pliocene (Dondi & Barbieri, 1982: Po Valley, Dieci, 1959: Tortonian, Pliocene). In Middle America, it is known from the Upper Eocene (Bolli et al., 1994), Miocene and Pliocene (Robertson, 1998), in California, from the Pleistocene (Robertson, 1998), in Australia, from the Upper Oligocene and Lower Miocene (Li & McGowran, 2000), in the India Ocean from the Pliocene and Pleistocene (Basov & Krasheninnikov, 1995), and in the Atlantic from the Pleistocene (Lévy et al., 1998). The species is extant; it is known from the Atlantic (Barker, 1960), Pacific (Dieci, 1959, Yassini & Jones, 1995) and Mediterranean (Dieci, 1959, cimerman & Langer, 1991, sgarrella & Moncharmont Zei, 1993). In the Central Paratethys, it appears from the Upper Eocene to the end of the Bade- nian (cicha et al., 1998). It is most frequent in the Karpatian and Badenian (ci-cha et al., 1971). In Austria, it is known from the Upper Eocene (Gohrbandt, 1961) and Karpatian (Rögl, 1969), and in Bavaria, from the Kiscellian to Ottnangian (Reiser, 1987: Lower Rupelian - Lower Egerian, Wenger, 1987: Upper Egerian -Lower Ottnangian). Remark: In the literature that discusses Paleogene sedimentary sequences (Eocene of Italy: Grünig (1985), Eocene of Slovenia: cimerman et al. (2006), Lower Egerian of Hungary: sztràkos (1979)), morphologically similar tests have been determined as the species Hoeglundina eocenica (Cushman & Hanna). In the study of Braga & Grünig (1975), the specimens noted as H. elegans from the Oligocene of Belgium are identified in the synonymy of the species H. eocenica from the Eocene of Italy. There are three possible interpretations of the citied literature above. That the species H. elegans ranges from the Eocene to Holocene, while the morphologically similar H. eocenica is restricted to the Paleogene only, where the two very similar species were coexistent. Alternatively, H. eocenica (Paleogene) and H. elegans (Neogene) may be chronologically distinct species; in this case identification of H. elegans in Paleogene strata would represent a false identification of H. eocenica. It is also possible that both names are only synonyms of one species, ranging from the Eocene to Holocene. Further comparative study of specimens from the Paleogene and Neogene is required to determine the relationship between both species. 210 Üblak, K. Distribution of robertininas in sections Species Ceratobulimina contraria and Hoeglundina elegans were found in all six sections (Figure 1). C. contraria appears in 15 samples from the Lower Badenian (Lower Lagenidae Zone) to Upper Badenian (Bolivina dilatata Zone). In Plohov breg and Sveta Ana sections, it is delimited to the Lower Badenian; in the early Lower Badenian (Lower Lagenidae Zone) it was found only in the sample Sa 17m of the Sveta Ana section, while in the late Lower Badenian (Upper Lagenidae Zone) it becomes more common in both sections. In other four sections: Imenska Gorca, Javoršica, Trobni Dol and Drensko Rebro, the species appears in the Middle and Upper Badenian only. The highest abundance is seen in the Upper Badenian sample J 33. H. elegans appears in 16 samples from the Lower Badenian Upper Lagenidae Zone to Upper Badenian Bolivina dilatata Zone. It is more common in the Middle and Upper Badenian with highest abundances being seen in Middle Badenian samples Td 3 and Dr 17. In sections Imenska Gorca, Javoršica, Trobni Dol and Drensko Rebro, the co-occurrence of both species is noted. Conclusions In Kozjansko (Eastern Slovenia), the fora-miniferal suborder Robertinina is represented with two species; Ceratobulimina contraria (Reuss) and Hoeglundina elegans (d'Orbigny). Both species were found in samples from the Lower to Upper Badenian. They are scarce in the Early Lower Badenian (Lower Lagenidae Zone) but increased abundance is noted in the Middle and Upper Badenian. Highest abundances are seen in the late Middle Badenian (Uvi-gerina cf. pygmea Zone) and in the early Upper Badenian (Bolivina dilatata Zone). Due to their occurrence throughout whole sections the species have little stratigraph-ic value for the Badenian, which coincides with previous studies of the Central Parat-ethys (cicha et al., 1998). Moreover, occurrence of the species Ceratobulimina contraria in Upper Badenian samples points to its even wider stratigraphic range; the last appearance data of the species is moved from the Middle Badenian (Gcha et al., 1998) to early Upper Badenian (this study). Both species are described, imaged, classified and represented by their exact occurrence through the sections for the first time in Slovenia. LEGEMdI i samplrwittwui rgbCüninas J JI «Kiptt с ünianiPfl roberünffBF О * • иге, frequent. ftumemus CkralobuSmma contraria О * • гаге, frequent, (iirniefoiu Hagìundma Figure 1. Frequence distribution of robertininas in the sections (after oblak, 2006); samples are listed in stratigraphic sequence Slika 1. Pojavljanje robertinin v profilih (po oblak, 2006); vzorci si sledijo v stratigrafskem zaporedju Povzetki Foraminiferni podred Robertinina iz badenija na Kozjanskem (vzhodna Slovenija) V prispevku je predstavljen foraminiferni podred Robertinina iz badenijskih plasti Kozjanskega. Podred Robertinina je bil opisan zadnji izmed dvanajstih foramini -fernih podredov, ki jih zajema foramini -ferna klasifikacija Loeblicha in Tappano-ve (1987). Podred vključuje foraminifere s planispiralno do trohospiralno zavitimi hišicami, večinoma notranje predeljeni-mi kamricami in steklasto porozno steno, zgrajeno iz strukturno in optično žarkovi-tega aragonita (Loeblich & Tappan, 1987). Stene hišic vseh preostalih steklastih fora-minifer, z izjemo v mezozoiku izumrlega podreda Involutinina, so namreč kalcitne. V podred Robertinina je po omenjeni klasifikaciji (Loeblich & Tappan, 1987) uvrščenih 48 rodov, s stratigrafskim razponom od zgornjega triasa do danes. Iz srednjega miocena je poznanih šest rodov, od tega v Evropi le štirje; Ceratobulimina Tou-la, 1915, Lamarckina (Berthelin, 1881), Hoeglundina Brotzen, 1948 in Robertina d'Orbigny, 1846. Glede na relativno majhno vrstno diverziteto v srednjemiocenskih sedimentih je podred Robertinina kot ta-kson v literaturi manj poznan. V Sloveniji je bila iz miocenskih plasti doslej določena le vrsta Hoeglundina elegans (Rijavec, 1975, 1976, 1977 in 1984, Petrica et al., 1995, Dozet et al., 1999). Na Kozjanskem je bilo vzorčenih šest profilov; Imenska Gorca, Plohov breg, Javor-šica, Sveta Ana, Trobni Dol in Drensko Rebro (Oblak, 2006), ki pripadajo Planinski sinklinali, oziroma zahodnemu obrobju nekdanje Centralne Paratetide (Buser, 1977& 1979, Aničić & Juriša 1984, Aničić & Juriša 1985, Aničić et al., 2004). Iz 128 vzorcev laporja in laporastega kalkarenita je bilo določenih 187 foraminifernih vrst iz sedmih podredov. Red Robertinina je zastopan z vrstama Ceratobulimina contraria (Reuss) in Hoeglundina elegans (d'Orbigny) in se pojavlja v vseh šestih profilih (slika 1). C. contraria je prisotna v vzorcih od starejšega spodnjega badenija (spodnja lagenidna biocona) do starejšega zgornjega badenija (biocona Bolivina dilatata), medtem ko se pojavlja H. elegans od mlajšega spodnjega badenija (zgornja lagenidna biocona) dalje. Obe vrsti sta najpogostejši v mlajšem srednjem badeniju (biocona Uvigerina cf. pygmea) in starejšem zgornjem badeniju (biocona Bolivina dilatata), kjer je opazen tudi trend skupnega pojavljanja. Prisotnost C. contraria v zgornjebade-nijskih vzorcih kaže na širši stratigrafski razpon kot je bil za območje Centralne Paratetide poznan doslej. Glede na dosedanje raziskave naj bi živela vrsta na tem območju namreč le do konca srednjega badenija (Qcha et al., 1998). Iz srednje-miocenskih sedimentov Slovenije vrsta še ni bila poznana. H. elegans, ki je bila iz srednjega miocena Slovenije že določena, je v prispevku prvič opisana, upodobljena in uvrščena v sistem. Acknowledgements I would like to express my thanks to Ivan Rakovec Institute of Palaeontology, ZRC SAZU for giving me the possibility to take SEM images. References Aničić, B., Juriša, M. (1984): Osnovna geološka karta SFRJ 1:100.000, list Rogatec, L 33-68. Zvezni geološki zavod, Beograd. Aničić, B., Juriša, m. (1985): Tolmač k Osnovni geološki karti SFRJ 1:100.000, list Rogatec L 33-68. Zvezni geološki zavod, Beograd, 76 str. Aničić, B., ügorelec, B., Dozet, s. (2004): Geološka karta Kozjanskega, 1:50.000. Geološki zavod Slovenije, Mladinska knjiga, Ljubljana. Barker, R. W. (1960): Taxonomic Notes on the Species Figured by H. B. Brady in his Report on the Foraminifera Dredged by H.M.S. Challenger During the Years 1873-1876. Accompained by a Reproduction of Brady's Plates. Soc. Econom. Paleont. Miner; Spec. Publ., Vol. 9, pp. 1-238, Tulsa. Basov, I. A., Krasheninnikov, V. A. (1995): Stratigraphy and Foraminifers of the Pliocene and Quaternary Deposits of the Timor Trough (the Indian Ocean). Naučni mir, Moskva, 112 pp. Bolli, H. M., Beckmann, J.-P., Saunders, J. B. (1994): Benthic foraminiferal bi-ostratigraphy of the south Caribbean region. Cambridge University Press, Cambridge, 408 p. Braga, G., Grunig, A. (1975): Foraminiferi bentonici dell'Eocene superiore. In: Braga, G., De Biase, R. Grünig, A. & Proto Decima, F., Foraminiferi ben-tonici del Paleocene ed Eocene della sezione di Possagno. Schweizerische Paläontologische Abhandlungen.; Vol. 97, pp. 85-199, Basel. Buser, S. (1977): Osnovna geološka karta SFRJ 1:100.000, list Celje L 33-67. Zvezni geološki zavod, Beograd. Buser, S. (1979): Tolmač k Osnovni geološki karti SFRJ 1:100.000, list Celje L 3367. Zvezni geološki zavod, Beograd, 72 str. Cicha, I., Rögl, F., Rupp, C., Ctyroka, J. (1998): Oligocene - Miocene foraminifera of the Central Paratethys. Abh. Senckenberg. Naturforsch. Ges.; Vol. 549, 325 p., Frankfurt am Main. Cicha, I., Zapletalovà, I., Papp, A., Ctyroka, J., Lehotayova, R. (1971): Die Fora-miniferen der Eggenburger Schichten-gruppe (incl. Arcellinida). In: Steininger, F. & Seneš, J. (Eds.), Chro-nostratigraphie und Neostratotypen, Miozän der Zentralen Paratethys. Bd. II, Eggenburgien, VEDA, Bratislava, pp. 234-355. Cimerman, F., Langer, M. R. (1991): Mediterranean Foraminifera. Dela IV. razreda SAZU.; Vol. 30, 118 str., Ljubljana. Cimerman, F., Jelen, B., Skaberne, D. (2006): Late Eocene benthic foraminiferal fauna from clastic sequence of the Socka - Dobrna area and its chrono-stratigraphic importance (Slovenia). Geologija.; Vol. 49/1, pp. 7-44, Ljubljana. Dieci, G. (1959): I foraminiferi tortoniani di Montegibbio e Castel Vetro. Palae-ontographia Italica.; Vol. LIV (n. ser. vol. XXIV), pp. 1-113, Pisa. Dondi, L., Barbieri, R. (1982): Foraminiferi Padani, Atlante iconografico e distribuzione stratigrafica (Terziario e Quaternario). AGIP S.p.A., Milano, 52 pls. Dozet, S., Rijavec, L., Grad, K. (1999): Western Kozje Area Tertiary (Eastern Slovenia). Rudarsko metalurški zbornik.; Vol. 46, No. 3, pp. 475-489, Ljubljana. Gohrbandt, K. (1961): Die Kleinforaminife-renfauna des obereozänen Anteils der Reigruber Serie bei Bruderndorf (Bezirk Korneuburg, Niederösterreich). Mitt. Geol. Ges.; Vol. 54, pp. 55-145, Wien. Gronig, A. (1985): Systematical description of Eocene benthic foraminifera of Possagno (Northern Italy), Sansoain (Northern Spain) and Biarritz (Aquitaine, France). Memorie di Scienze Geologische, Inst. Geol. Mineal. Uni. Padova.; Vol. XXXVII, pp. 251-302, Padova. Langer, W. (1969): Beitrag zur Kenntnis einiger Foraminiferen aus dem mittleren und oberen Miozän des NordseeBeckens. N. Jb. Geol. Paläont. Abh.; Vol. 133, pp. 23-78, Stuttgart. Lévy, a., Mathieu, R., Poignant, a., Ros-set-Moulinier, M. (1998): 44. Data Report: Distribution of Pleistocene Benthic Foraminifers from the Eastern Equatorial Atlantic Ocean. In: Ma-scle, J., Lohmann, G. P. & Moullade, M. (Eds), Proceedings of the Ocean Drilling Program, Scientific Results.; Vol. 159, pp. 605-610, Texas. Li, Q., McGowran, B. (2000): Miocene foraminifera from Lakes Entrance Oil Shaft, Gippsland, southeastern Australia. Memoir of the Association of Australasian Palaeontologists.; Vol. 22, pp. 1-142, Canberra. Loeblich, A. R. Jr., Tappan, H. (1984): Supra-generic classification of the Forami-niferida (Protozoa). Micropaleonto-logy; Vol. 30, No. 1, pp. 1-70, New York. Loeblich, A. R. Jr., Tappan, H. (1987): Foraminiferal Genera and their Classification.; Vol. 1-2, 970 p., 847pls., Van Nostrand Reinhold, New York. d'Orbigny, A. (1826): Tableau Méthodique de la Classe des Céphalopodes. Ann. Sci. D'Hist. Nat.; Ser. 7, pp. 7-150, Paris. Oblak, K. (2006): Foraminiferna taksonomi-ja, biostratigrafija in paleoekologija badenija v Planinski sinklinali (vzhodna Slovenija, Centralna Paratetida) : Ph.D. Thesis. Ljubljana: University of Ljubljana 2006; 310 p, 60 pls. Papp, A., Schmid, M. E. (1985): Die Fossilen Foraminiferen des Tertiären Beckens von Wien. Revision der Monographie von Alcide d'Orbigny (1846). Abh. Geol. Bundesanst.; Vol. 37, 311 p., Wien. Petrica, R., Rijavec, L., Dozet, s. (1995): Stra- Robertson, B. E. (1998): Systematics and pa- tigraphy of the Upper Oligocene and leoecology of the benthic Foraminife- Miocene beds in the Trobni Dol area rida from the Buff Bay section, Mio- (Kozjansko). Rudarsko metalurški cene of Jamaica. Micropaleontology.; zbornik.; Vol. 42, No. 3-4, pp. 127- Vol. 44, No. 2, 266 p., New York. 141, Ljubljana. Rögl, F. (1969): Die miozäne Foraminiferen- Popescu, G. (1975): Études des foraminifères fauna von Laa an der Thaya in der du miocène inférieur et moyen du no- Molassezone von Niederösterreich. rd-ouest de la Transylvanie. Mémoires Mitt. Geol. Ges.; Vol. 61, pp. 63-123, Inst. Géol. Géophys.; Vol. XXIII, pp. Wien. 5-121, Bucarest. sgarrella, F., Moncharmont Zei, M. (1993): Reiser, H. (1987): Die Foraminiferen der baye- Benthic foraminifera of the Gulf of rischen Oligozän - Molasse; Systema- Naples (Italy): systematics and auto-tik, Stratigraphie und Paläobathyme- ecology. Boll. Soc. Paleont. Ital.; Vol. trie. Zitteliana.; Vol. 16, pp. 3-131, 32, No. 2, pp. 145-264, Modena. München. sztràkos, K. (1979): La stratigraphie, paléoé-Reuss, a. E. (1851): Über die fossilen Forami- cologie, paléogéographie et les niferen und Entomostraceen der Sep- Foraminifères de l'Oligocène du no-tarienthone der Umgegend von Ber- rd-est de la Hongrie. Cahiers Micro-lin. Zeitsch. Deut. Geol. Gesel.; Vol. paléontologie.; Vol. 3, 95 p., Paris. 3, pp. 49-92, Berlin. Wenger, W. F. (1987): Die Foraminiferen des Rijavec, L. (1975): Korelacija miocenskihpla- Miozäns der bayerischen Molasse und sti v vzhodni Sloveniji, II. faza. Arhiv ihre stratigraphische sowie paläogeo-geološkega zavoda Slovenije, 63 p., graphische Auswertung. Zitteliana.; Ljubljana. Vol. 16, pp. 173-340, München. Rijavec, L. (1976): Korelacija miocenskih pla- Yassini I., Jones, B. g. (1995): Recent Forasti v vzhodni Sloveniji, III. faza. Arhiv miniferida and Ostracoda from estu-geološkega zavoda Slovenije, 52 p., arine and shelf environments on the Ljubljana. southeastern coast of Australia. The Rijavec, L. (1977): Korelacija miocenskih pla- University of Wollongong Press, Wol-sti v vzhodni Sloveniji, IV faza. Arhiv longong, 484 p. geološkega zavoda Slovenije, 56 p., Ljubljana. Rijavec, L. (1984): Oligocen i miocen područja izmedju Rudnice i Boča (istočna Slovenija) na osnovi mikrofosila: Ph.D. Thesis. Zagreb: Sveučilište u Zagrebu, Prirodoslovno-matematički fakultet Zagreb 1984, 141 p. Geological characteristics of the terrain along Vc corridor between Sava river and Sarajevo town Mirza Bašagić 1, Nijaz Skripić 1, Ferid skopljak 1 1 Civil Engineering Faculty of University of Sarajevo, Geology Institute, Stjepana Tomića st. 3, 71000 Sarajevo, B&H; E-mail: mbasagic@lol.ba. Received: March 25, 2007 Accepted: August 20, 2007 Abstract: On the basis of analyzed geological, tectonic, seismic-tectonic, hydro and engineering geological characteristics of terrain, in this paper are reviewed geotechnical conditions for construction of highway, as a part of Vc Corridor through Bosnia and Herzegovina, between Sava river in the north and Sarajevo, i.e. Tarčin town in the south. Along northern half of BH-highway, 165 km long, it would be necessary to construct 37 tunnels in total length of 30.2 km and 119 bridges (viaducts) with 13 road junctions. Highway route mainly extends along river Bosna valley, in terrain with heterogeneous geological structure and complex structural-tectonic structure. It diagonally crosses structure of Dinaric Alps and active seismic-tectonic zones with intensity of up to 7 EMS. In regards to structural-geologic relations, subjects of change are also hydrogeological categories, porosity and functions of rock masses. However, highway is not in collision with water supply systems or significant water source areas. Regarding the fact that hard and stable rock masses are dominant in terrain, up to 3/4 of considered terrain belongs to favourable category for construction works. Exceptions are zones with thick covers along notches and particularly instable landslide zones within Zenica and Kakanj areas. Those parts, unfavourable for construction works are placed in about 1/4 of considered route. Key words: highway, corridor, geological structure, tectonic structure, seismic-tectonic zones, hydrogeological and engineering geological characteristics, stability, and favourability for construction works Introduction In the aim of establishment of direct road connection between Baltic and Adriatic Sea, in other words between countries of north, central and south Europe, construction of a highway in Corridor Vc is planned (Baltic-Adriatic). South part of future highway is also placed through Bosnia and Herzegovina, in length of 330 km. From the north state border, from the bridge across Sava river near Svilaj, highway is placed along river Bosna valley and in the area near Modriča, Doboj, Tešanj, Zenica, Sarajevo and Mostar cities, in its south part, along valleys of river Neretva, it connects to Adriatic - Ionic motorway in Republic of Croatia. North half part of BH corridor, in length of 164.93 km extends between Sava River and Sarajevo (Tarčin). Inside mentioned section, 37 tunnels in total length of 30,253 m shall be constructed as well as 119 bridges (viaducts), in other words structures, and 13 junctions (road loops). This paper represents review of geological-tectonic, seismic-tectonic and hydrogeological-engineering geological characteristics of terrain and geotechni-cal conditions for construction of highway along mentioned section. Results and discussion Physical and geographic characteristics Relief between Svilaj and Tarčin is uneven in morphologic aspect. Up to Doboj it belongs to a plain south edge of Pannonia lowland. From Doboj to Tarčin, road route in its main part extends along the valley of river Bosna, inside Dinaric Alps massif with hilly-mountain relief. The lowest altitudes are in the north, along riverbeds of Bosna and Sava, between 85 - 120 m a.s.l. In south direction, in the area of mountain ranges, altitude increases from 500 to over 1000 m a.s.l. Geological structure In geological structure, rock systems of Phanerozoic • Palaeozoic rock systems (Pz) compose south part of reviewed terrain. They are composed of philite, quartz-sericite schist with lenses of lidite, quartzite, quartz-porphyre, dolomite, limestone and marble of Devonian (D), and Permian conglomerate, sandstone and shale (P), and to Permian Triassic (P,T) belong shaley marly limestone in the area of Tarčin. • Mesozoic rock systems (Mz) compose middle part of terrain. They are characterized with great variety of facies. • Within lower Triassic (T1) represented are sandstone, schist, marl and limestone, and both stages of middle Trias-sic (T2) are composed of limestone and dolomite of Anisian (T^), and igneous-sedimentary formation of Ladinian (T22). Massive microsparite belongs to upper Triassic (T3). • Jurassic sediments (J) are extended from river Rudanka and Doboj, to Nemila. Dominant is igneous-sedimentary formation, more precisely ophiolite "melange". • Transitional horizons of Jurassic and Cretaceous (J, K) are represented in fly-sch like rocks, as "Nemila" (1J,K) and "Vranduk" sediments (2J,K). • Upper Cretaceous (K2) is characterised with so called "carbonate flysch" (limestone, breccia, subordinating pelite-alevrolite and marl in exchange). • Cainozoic (Kz) is represented with sediments of Palaeogene, Neogene and Quaternary, which are extended in Posavina and along valley of Bosna. • Palaeogene, more precisely Palaeocene-Eocene sediments (Pc,E) are developed in clastic and carbonate facie, and Eocene sediments (E) are composed of limestone-sandstone and facie of flysch. • Oligocene-Miocene sediments (Ol, M) are represented with conglomerate, sandstone, marl, clay and travertine limestone. • Neogene (N) is composed of sediments of Miocene and Pliocene. Miocene (M) sediments are conglomerate, sandstone, clay, marl and limestone with occurrences of coal in Sarajevo-Zenica and Šeher-Žepče basin. Pliocene and Pliocene-Quaternary rock systems (Pl; Pl,Q) are sand, gravel and clay, and in Pliocene, coal also occurs. • Quaternary surface covers of detritus-sand-clay composition have significant extension, especially in Posavina and on the slopes along river valleys, especially in parts where basic terrain structure is composed of clastic, clayey-marly sediments. Tectonic structure In tectonic aspect, the area of road route belongs to a region of inner Dinaric Alps and it extends over so called "zone of Palaeozoic schist and Mesozoic limestone", with central ophiolitic zone. Main folding structure is represented with fold of Bosnian flysch which crosses middle part of road route near Nemila. As main fault structures, determined are Spreča-Kozara and Busovača deep faults. Besides deep faults, there are also faults of the first category (Neo tectonic faults), and faults of the second category that crosses surface parts of terrain along the road route. Seismic-tectonic zones Deep fractures represent areas of contemporary tectonic movements that are the most common causes of occurrence of earthquakes. In that aspect, there are following seismic-tectonic zones: Sava -Modriča; Modriča - Doboj; Usora - Maglaj; Žepče - Vranduk and Sarajevo - Zenica basin. Within those zones, prognosticated intensity of earthquakes for returning period of 500 years is 6 o - 7 o EMS. Hydrogeological relations According to hydrogeological categories, porosity and functions of rock masses, in terrain are represented water permeable and watertight rocks. Water permeable rocks are characterised with crack-cavernous and intergranular porosity structures, and according to permeability and functions there are highly water permeable and moderately water permeable underground and surface aquifers. Springs occur mainly in carbonate rocks of crack-cavernous porosity. In rocks of intergranular porosity, formed are "free" water bearing layers out of which water is used for water supply, like they are water sources in Odžak, Ru-danka near Doboj, Jelah near Tešanj, near Žepče, Zenica, Kakanj, Sarajevo, etc. Watertight igneous, metamorphic and clayey-marly sedimentary rocks, in dependence of structural position, have a function of hydrogeological barriers in terrain. Engineering geological characteristics According to engineering geological clas- Figure 1. Geological map of Bosnia and Herzegovina (Hrvatović, H., 1999) sification, rock masses are divided as main mapped units and selected in taxonomic units as: lithological types (LT), complexes (LC) and suites (LS). According to grade of diagenesis and strength of bonds of mineral aggregates, selected units are divided into two basic groups: - hard and soft rocks, in other words masses of geological substrata, and - coherent and incoherent soil, in other words surface covers of different genesis types. Within group of hard and soft rocks, selected are 22 lithological complexes (LC) and 13 lithological types (LT). And within group of coherent and incoherent soil, se- lected are 6 lithological complexes (LC). On the basis of engineering geological characteristics, performed was classification and definition of rock masses as real environments where highway would be constructed. According to stability and en-dangerment of contemporary exodynamic and techno-genetic processes and occurrences, and satisfaction for construction, selected are three categories: - the first category: instable areas, unsatisfactory for constructions; - the second category: conditionally stable areas, conditionally satisfactory for constructions; - the third category: stabile areas, satisfactory for constructions. In reviewed section that is 164.93 km long, 3/4 of road route is placed in stabile terrain, satisfactory for construction, and only 1/4 of road route is placed in conditionally, and instable terrain. Geotechnical conditions for constructions In aspect of geotechnical conditions for construction, the following can be summarised: •In plain parts, which are composed of gravel-sand sediments, difficulties during construction are not expected, besides local occurrence of higher levels of underground water, what should be considered during disposition of road route level. •In aspect of satisfaction for construction, that areas belong to category of satisfactory and stabile terrains. •Middle part of road route, between Do-boj and Zenica, is characterised with heterogeneous lithological composition and variable physical-mechanical characteristics of rocks that create complex geotechnical conditions for constructions. •In that part, along road route, occurrences of disturbed stability of slopes could be expected, especially in parts where thicker covers are present as well as in parts of substrata that are more decayed, in portal parts of tunnels and zones of foundations of bridge constructions (tunnel Crni Vrh, tunnels between Ozimica - Nemila, bridges over river Bosna, etc). •In aspect of geological-geotechnical conditions for construction, the greatest difficulties are expected in the area of bypassing city of Zenica, because road route between Donja Gračanica and Drivuša is placed along instable and conditionally stable slopes. •Along section Drivuša - Kakanj, road route is placed in terrain that is composed of clastic sediments with formed thicker cover and decayed parts of basic substrata, and landslide Tičići should also be emphasized, which together with "Zenica" landslides represent the most important occurrence of instable parts of terrain. •Within tertiary marly-clayey rocks along tunnel, occurrences of rock yielding, underground pressures, rock collapsing, etc. should be expected, while in carbonate-clastic zones, some better conditions could be expected. •Along section between Vlakovo and Tarčin, road route is mainly placed inside tunnels in limestone and igneous-metamorphic rocks, but construction conditions could be evaluated as satisfactory. •In aspect of construction of tunnels, limestone and "healthy" igneous-meta-morphic rocks represent satisfactory working environment, even though fault zones could be expected in them together with scattered outbursts and occurrences of underground water. Conclusions On the basis of analysed relevant engineering geological parameters: lithofacie composition, conditions and characteristics of rock masses, morphologic characteristics, exodynamic geological processes and occurrences, angle of stability of natural slopes, hydrogeological and seismic characteristics along Corridor Vc in section between river Sava in the north and Sarajevo, more exactly Tarčin in the south, it can be concluded that geotechnical conditions for References Bašagić, M., Langof, Z., škripić, n., Skopljak, F. (2005): Highway in Corridor Vc, Planning-study documentation, Technical study, Elaborate on engineering geological, hydrogeological and geotechnical conditions for construction. Book 2.3, LOT N° 1&2, IPSA, Sarajevo, pp. 1-31. Bračinac, Z. (1966): Basic seismic-tectonic map of SR BH, 1:200,000. Institute for engineering geology and hydroge-ology, Sarajevo. Cičić, S. (2002): Geological composition and tectonic of terrain of Bosnia and Herzegovina (in Bosnian). Sarajevo, 311 p. Hrvatović, H. (1999): Geological guide through Bosnia and Herzegovina, Monographic (in Bosnian). Geological Herald.; XXIV, Sarajevo, pp. 1-203. construction are satisfactory in the most part. Regarding the fact that in terrain dominating are hard and stabile rock masses, that means that 3/4 of reviewed section belongs to more satisfactory category for construction. Exceptions to this are zones with thicker covers in notches and especially instable zones of landslides in the area of Zenica and Kakanj. Suitability for construction is represented also with a fact that road route of future highway is not in collision with water supply systems or more significant water sources. Rokić, L. (1989): Role and importance of engineering geological modifiers to engineering geological characteristics of terrain of middle Bosnia. Institute for geotechnics and foundations, Civil Engineering Faculty of Sarajevo, Sarajevo, pp. 1-169. vidović, M., Mojičević, M. (1975): General Tectonic Map of Bosnia and Herzegovina. Seismic Institute of BH, Sarajevo. Environmental protection and investment costs as factors of road placement Okolje in investicijski stroški kot dejavnika za umeščanje cestne trase v prostor Heda Kočevar 1, Marko Šetinc 1 1 OMEGAconsult d.o.o., Gregorčičeva ulica 7, SI-1000 Ljubljana, Slovenia; E-mail: heda.kocevar@omegaconsult.si, marko.setinc@omegaconsult.si Received: May 31, 2007 Accepted: September 5, 2007 Abstract: In the article, a methodology to aid the choice of the most appropriate road corridor from the standpoint of environmental protections and investment costs is presented. The methodology enables road planners to first define the route or so called corridor, which according to the selected factors is most acceptable and expert grounded, and in the next phase work out multiple combinations of previously "pure" scenarios. On the basis of additional evaluations, political preferences, financial capabilities and social acceptability, the most appropriate corridor for placement of a new road is chosen. Inside of the corridor, the most technically feasible route of new road is then drawn. The advantage of such an approach is foremost in the objectivity of the methodology and the simultaneous command of multiple factors when choosing the most appropriate corridor. The classic method of route placing has its roots in technical placement; and these alternatives are evaluated between each other from multiple perspectives. Izvleček: V prispevku je prikazana metodologija določitve najugodnejšega cestnega koridorja z vidika varovanja okolja in investicijskih stroškov gradnje ceste. Metodologija omogoča načrtovalcu najprej definirati t.i. koridorje, ki so glede na izbrane vplive najugodnejši ter strokovno in objektivno čim bolj utemeljeni. V naslednji stopnji se lahko izdela tudi različne kombinacije prejšnjih »čistih« koridorjev. Med vsemi predlaganimi koridorji se na podlagi dodatnih vrednotenj, političnih preferenc, finančnih zmožnosti in družbene sprejemljivosti izbere tistega, ki je najbolj ustrezen. Znotraj koridorja se nato izriše tehnično najbolj ugodna trasa ceste. Prednost takega pristopa je predvsem v objektivnosti metodologije in v hkratnem obvladovanju več dejavnikov, ko izbiramo najugodnejši koridor. Klasična metoda umeščanja cestne trase v prostor namreč izhaja najprej iz tehnične umestitve, šele kasneje pa se različne variante, določene na tak način, med sabo vrednoti z različnih vidikov. 224 KoČEVAR, H., šETINC, M. Key words: road planning, environmental vulnerability, investment costs, GIS, methodology Ključne besede: načrtovanje cest, ranljivost okolja, investicijski stroški, GIS, metodologija Introduction The construction of an infrastructure network is an important task that enables development of individual parts of the country as well as of the state as a whole. In road network planning - the largest in scope and complexity in infrastructure - we generally find many different approaches. The most frequent, and also the most commonly used, is the so-called »technical« approach[1]. With this approach, the alternative individual routes according to technical criteria are chosen first, and then are judged in view of the environmental and spatial impact later. Adequate protection measures are included in this approach. The second approach, originally introduced in Germany, and now utilized in Slovenia, is the so called "spatial" approach[1]. The purpose of this approach is to determine the spatial and environmental vulnerability of a particular route chosen. First, the narrow, spatially acceptable corridor is chosen. Then within the corridor alternative routes are designed according to technical criteria. A choice of factors to include in route selection modelling methodology, depend on the goals we wish to achieve. In most cases environmental vulnerability is the only factor. Environmental protection is becoming an increasingly important issue in today's world. Besides an increased public aware- ness of the need for environmental protection, Slovenia has with joining the EU in 2004 adopted European legislation, which places an even greater emphasis on environmental protection. It is important that the construction of new road connections does not harm the natural state of the environment, or cultural heritage. With project planning it is therefore paramount that the construction of the road connection itself impacts on the environment as little as possible. The second most important factor that influences road placement and construction are investment costs. Usually, the available funds are smaller than requested, so the goal is to find the solution which enables the greatest benefit for road users and society as a whole at the lowest cost possible. This article represents a useful introduction to the application of GIS methodologies to solve a transportation problem. In this paper appropriate methodology which allows optimal route determination in space, with regard to both environmental protection, and investment costs is utilized. The optimization of all different constrains is very important in road design, because a suitable initial approach results in substantial savings (in terms of both money and the environment) when it comes to further realization of plans and projects. Methodology In a broader sense the geographic information system (GIS) is an information system specializing in the input, storage, manipulation, analysis and reporting of geographical (spatially related) information[2]. Information in GIS is often stored and represented as layers, which are sets of geographical features linked with their attributes. Before a GIS can be use to solve the problems, data must be properly chosen and represented in a digital computing environment. Route selection or road planning is an example of the impact of multiple geographical constraints in nature. The route selection process is in fact a multi-criteria decision making process where a final decision is made by considering different types of information. The task is to define a route linking the previously identified start and end points. The goal is to insure that the road route chosen is the shortest, least expensive (i.e. presents minimum investment costs), and does the least harm to the environment (i.e. maximum environmental preservation). Some criteria are self reinforcing, such as road length and investment costs, while others are mutually exclusive, such as road length and environmental damage. An appropriate balance which tries to satisfy divergent interests must be found. The methodology for the optimal corridor or route selection can be divided into 5 steps. The first three are used for new data layer synthesis, for each factor separately (environment, costs, etc.), while the last two are used for optimal corridor modelling of all the factors combined (Figure 1). Figure 1. Schematic representation of methodology for route selection Slika 1. Shematska predstavitev metodologije za umeščanje cestne trase v prostor In the first stage data layer selection on an environmental protection basis is performed. The layers represent protected areas as defined by legislation or otherwise designated as protected. At this point, digital data layers of the space in question are collected and modified with the use of GIS tools. Areas where protection of the environment is called for are generally areas less (or not at all) appropriate for the placement of new road. In the second stage, depending on the meaning of a particular area, the weights for each individual layer are assigned. The more that a certain area needs to be protected, the larger the weight assigned to that layer. The weight actually shows how much longer a route between two points will be drawn, as opposite to the most direct path of the route. If too large weight is assigned, the environment is more protected (because the route will take the path across less protected areas); however the investment costs will be significantly higher, and the new road too long. In the third stage, vector data is converted to raster data. Every point is assigned a value, which represents the sum of the values of individual layers (layers, selected in the first stage and weights, assigned in the second). Areas with the highest values are least appropriate for new road determination from the standpoint of protection of the environment. Cost analysis is performed in a similar way as the environmental protection analysis. In the first stage, layers which lead to increased costs of construction of the new road are determined. For example, a large change in above sea level elevation (influence on the construction of tunnels and viaducts), potential avalanche areas or other geologically and hydrologically inappropriate areas on which the construction of roads is much more difficult. At this stage the expert geological opinion and judgement is very important. Individual layers are weighted in the second stage, with an eye as to how much they increase the total costs of construction of the new road connection. In the third stage, individual layers in raster form are combined and the values of individual overlapping areas summarized. In the fourth stage, the most environmentally appropriate corridor is placed. The new road is placed in a location which cumulatively has the least negative impact on the environment. This is determined with the help of appropriate GIS tools. In the same way a corridor which from a construction standpoint is lowest in cost is drawn. The two corridors determined in the fourth stage can have a similar path or can be considerably different. In the case of a considerable difference, a new corridor is determined, which represents the most optimal route between the two, in other words the most appropriate route of the new road, which would attain the lowest possible cost while not neglecting protection of the environment. In this process, every factor (environmental, cost analysis) can be assigned a weight, which is an expression of the degree of importance we assign to each perspective. Differing weights can fundamentally alter the placement of the new road route. A 4 Figure 2. Composite map of environmental layers Slika 2. Karta, sestavljena iz posameznih plasti varovanih delov okolja Results and Discussion For the presentation of the introduced methodology, a portion of southeast Slovenia was chosen. Selected digital layers for the environmental protection analysis included: - Natura 2000 areas, - protected areas of nature, - valuable natural features, - ecologically important zones, - water protection zones, - cultural heritage. For definition of a favourable corridor with regard to road construction cost analysis, the following layers were applied: - relief (slope), - sensible regions (flooded areas, erosion areas, landslide areas), - waters and lakes, - objects (buildings etc.). In this paper, all selected data layers have equal weight. If the importance or influence of certain data is determined to be greater than that of other data, the assigned weight should be heavier. In Figure 2, the composite map of all environmental layers is presented. The darker zones correspond to several protected areas. These are the areas less suitable for new road construction. The most appropriate areas for new road placement are in white. In the next stage, data is converted from vector format into raster format, and the most appropriate new road corridor from the environmental protection as well as cost perspective is drawn with the help of appropriate GIS tools. In Figure 3, the first picture on the top left is environmentally the most appropriate corridor, while the last picture on the bottom right is the most appropriate route from a cost perspective. The goal of the new road planner is to find a solution which will protect the environment to the highest degree possible at the lowest possible cost. Because two conditions that aren't directly comparable need to be satisfied in the final and most optimal corridor, there are many solutions which can be represented graphically (Figure 4 - gray and black points). The best solutions are the black points, which lay along the Pareto[3] curve. The Pareto trade-off curve is the curve made up of Pareto points that represent possible solutions. For all the points on the curve it holds true that in giving more importance to one factor it is automatically assigned less importance to the other. All the points present an equal solution to the problem -no particular one is better than any other. If we apply the Pareto model to the display of determination of the most appropriate corridor for road placement from an investment costs as well as environmental protection perspective (Figure 3), it can be determined that all the solutions displayed correspond to points on the Pareto curve. The next goal is to find the solution, which will be utilized in actual practice. Comparison of the individual pictures in Figure 3 show that the model of proportions varies from costs 80 %: environment 20 % to costs 10 %: environment 90 % show territory which is in common to all the models. This territory can thus be tak- Figure 3. Optimal road corridors as a result of the corridor modelling (E - environment, I - investment) Slika 3. Modelsko določeni optimalni koridorji poteka ceste (E - okolje, I -investicija) Figure 4. Pareto optimality curve Slika 4. Paretova optimizacijska krivulja en as the most convenient corridor for the construction of a new road. Inside of this corridor various alternatives can be determined, evaluated and compared with each other in classic approach. The choice of the most optimal route for a new road as demonstrated above is not always simple. In a way it is a political decision, because it entails deciding how important protection of the environment is in financial terms. Social acceptance plays an important role within this process, as does the influence the new road would have on the development of a particular area. The methodology demonstrated allows for individual alternatives which enter the political foray to be expertly and objectively supported to the maximum extent possible. In the demonstrated model two groups of limitations (environmental protection and investment costs) are included, even though more groups could be included. Possible limitations, which could also be included in the model, are: - limitations of space (for example, neighbourhoods - limiting factor regarding the construction of road, though at the same time also a factor of attractiveness in space), - physical barriers (unfavourable terrain, geological or hydrological conditions, water streams, lakes), - economic potential (industrial zones, tourist zones, accessibility and the connectedness of town centres), - political limitations and social acceptance. Conclusions In construction of transport infrastructure the question of how to intervene with minimal impact on the environment yet at the same time in a technically most feasible and cost effective way is a common problem. Every intervention into nature affects the environment. The planner's task is to pick the solution which will do the least harm to the environment while providing the greatest economical benefit. In the article, a methodology to aid the choice of the most appropriate road corridor from the standpoint of the environment protections and investment costs is presented. The methodology enables road planners to determine the route or corridor, which according to the selected factors is most acceptable, and in the next phase work out multiple combinations of previously »pure« scenarios. On the basis of additional evaluations, political preferences, financial capabilities and social accept- ability, the most appropriate corridor for placement of a new road is chosen. Inside of the corridor, the most technically feasible route of new road is then drawn. In spite of computer support importance for methodology execution, preparing the input data needs an expert knowledge and cooperation of different specialists. Selection and data layers synthesis needs the knowledge of geology, hydrology, civil engineering, environment, legislation, land use, etc. Only professional prepared and grounded input data enable optimal results. The advantage of such an approach is foremost in the objectivity of the methodology and the simultaneous command of multiple factors when choosing the most appropriate corridor. The classic method of placing the road route in space has its roots in technical placement; only later are alternatives evaluated between each other from multiple perspectives. Povzetki Okolje in investicijski stroški kot dejavnika za umeščanje cestne trase v prostor Pri gradnji prometne infrastrukture se vedno srečujemo z dilemo kako poseči v prostor, da bo okolje kar najmanj prizadeto, in hkrati najti tehnično najugodnejšo rešitev, ki bo tudi stroškovno ugodna. Vsak poseg v okolje prizadene tudi naravo. Načrtoval-čeva naloga je, da izbere tako rešitev, ki ponuja ob najmanjši prizadetosti okolja, največjo ekonomsko korist. Izbor posameznih dejavnikov, ki jih vključimo v metodologijo za določitev sprejemljivega infrastrukturnega koridorja, je lahko zelo različen, odvisno od cilja, ki ga želimo doseči. Večinoma je tak dejavnik samo eden, to so različna varovana območja okolja. V tem primeru projektant izriše traso ceste tako, da poteka čim manjši meri čez varovana območja. V metodologijo pa lahko vključimo tudi druge dejavnike. V prispevku je prikazana metodologija določitve najugodnejšega cestnega koridorja z 232 KoČEVAR, H., šETINC, M. vidika varovanja okolja in investicijskih stroškov gradnje ceste. Predlagana metodologija za umeščanje cestne trase v prostor vsebuje več stopenj (slika 1): 1. Določi se področja, ki so povezana z varovanjem okolja. To so varovana območja, določena v zakonskih ali podzakonskih aktih, ali pa jim je na kakšen drug način pripisan varovalni pomen. Na tej stopnji se zbere plasti digitalnih prostorskih podatkov in se jih ustrezno obdela z orodji GIS (slika 2). 2. Glede na pomen posameznega področja se določi uteži za posamezno plast. Bolj ko želimo neko območje ali dobrino varovati, večjo utež dobi. Če določimo preveliko utež, okolje sicer bolj varujemo (ker bo izrisana pot prečkala malo varovanih območij), a bo nova cesta daljša in investicijski stroški bistveno višji. 3. Vektorske podatke pretvorimo v rastrske. Vsaki točki pripišemo vrednost, ki predstavlja vsoto vrednosti posameznih plasti (plasti, izbranih v prvi stopnji in uteži, izbranih v drugi stopnji). Področja z najvišjo vrednostjo so najmanj primerna za izdelavo nove cestne povezave z vidika varovanja okolja. Na podoben način kot okoljski vidik se izdela tudi stroškovnega. V prvi stopnji se določi plasti, ki vplivajo na povečanje stroškov pri izgradnji cestne povezave. To so na primer velika sprememba nadmorske višina (vpliva na gradnjo tunelov in viaduktov), plazovita območja oz. geolo- ško in hidrogeološko neugodna območja, na katerih je gradnja ceste bistveno zahtevnejša. V tej stopnji je zelo pomembna tudi strokovna geološka ocena. Posamezne plasti se v drugem delu ustrezno uteži. V tretji stopnji se posamezne plasti v rastrski obliki združi in vrednosti na posameznih prekrivajočih področjih sešteje. 4. Na podlagi ovrednotenih površin iz tretje točke se s pomočjo ustreznega GIS orodja izdela najustreznejši koridor z vidika varstva okolja in koridor, ki je z vidika stroškov izgradnje cestnega odseka najugodnejši. 5. Koridorja, dobljena v četrti stopnji, sta si po poteku lahko podobna ali pa se bistveno razlikujeta. V primeru bistvene razlike se izdela še koridor, ki predstavlja optimum med obema »čistima« koridorjema, torej kje je najprimernejši potek cestne trese, ko bi z najnižjimi stroški dosegli največje varovanje narave. Pri tem postopku lahko vsakemu od vidikov (okolje, stroški) določimo poljubno utež, ki je odraz tega, kateremu vidiku dajemo večji pomen. Različne uteži lahko bistveno spremenijo potek trase. Na sliki 3 je na prvi sliki prikazan okolj-sko najprimernejši koridor, na zadnji sliki pa investicijsko najugodnejši koridor. Cilj načrtovalca cestne povezave je najti tako rešitev, ki bo ob najnižjih stroških najbolj okoljsko ugodna. Ker v končnem koridorju združujemo dve lastnosti, ki nista neposredno primerljivi, obstaja veliko rešitev, kar lahko ponazorimo tudi grafično (slika 4 - sive in črne točke). Najboljše rešitve so črne točke, ki ležijo na t.i. Paretovi krivulji[3]. Za vse točke na tej krivulji je značilno, da če hočemo eno lastnost izboljšati, se pri tem druga poslabša. Pri tem vse te točke predstavljajo enakovredne rešitve problema - nobena ni boljša od druge. Če prenesemo Paretov model na prikaz izdelave najbolj ugodnega koridorja izgradnje cestne povezave tako s stroškovnega kot tudi okoljskega vidika (slika 3), lahko ugotovimo, da vse prikazane rešitve ustrezajo točkam na Paretovi krivulji. Naslednji cilj je torej najti rešitev, ki jo bomo uporabili v praksi. Primerjava posameznih slik pokaže, da vsebujejo vsi modeli od razmerja okolje: stroški 80 %:20 % do razmerja 10 %:90 % v okviru najugodnejšega koridorja tudi ozemlje, ki je vsem tem modelom skupno. To ozemlje lahko zato pojmujemo kot najbolj ugodni koridor za izgradnjo ceste. Znotraj tega koridorja pa kasneje projektant izriše več variant, ki jih vrednotimo in primerjamo med sabo na klasičen način. Kljub pomembnosti računalniške podpore pri izpeljavi metodologije je potrebno pri pripravi vhodnih podatkov veliko strokovnega znanja in sodelovanje strokovnjakov z različnih področij. Izdelava in izbira podatkovnih plasti zahteva znanja s področja geologije, hidrogeologije, gradbeništva, okolja, poznavanja zakonodaje, rabe tal, urejanja prostora itd. Le strokovno pripravljeni in utemeljeni vhodni podatki omogočajo optimalne rezultate. Zgoraj prikazana izbira najugodnejšega koridorja ni vedno enostavna. Dejansko je to »politična« odločitev, saj se moramo odločiti, koliko nam pomeni varovanje okolja v denarnem smislu. Pri tem igra pomembno vlogo tudi družbena sprejemljivost in pa vpliv, ki bi ga imela nova cesta na razvoj območja. Prikazana metoda pa omogoča, da so posamezne različice, ki pridejo v »politično« presojo, čimbolj strokovno in objektivno utemeljene. References [1] Radakovič, M., Marušič, J., Juvanc, A. (2006): Načrtovanje cestne povezave na podlagi ranljivosti okolja. Simpozij 3. razvojna os - slovenski projekt 3. tisočletja. Maribor, 21.3.2006, Fakulteta za gradbeništvo: Društvo za ceste Maribor, pp. 77-82. [2] Rodrigue, J.-P., Comtois, C., Slack, B. (2006): The geography of transport systems. Routledge, London and New York, 284 pp. [3] Heydemann, K., Bodin, F.: Iterative Compilation for Two Antagonistic Criteria: Performance and Code Size Case Study [cited 17.1.1007]. Dostopno na svetovnem spletu: Designing a national groundwater quantity monitoring network on groundwater bodies with alluvial aquifers in Slovenia Načrtovanje državne mreže za spremljanje količin podzemne vode na vodnih telesih podzemne vode z aluvialnimi vodonosniki Petra Souvent 1, Zlatko Mikulič 1, Mišo Andjelov 1, vlado Savić 1 1 Environmental Agency of the Republic of Slovenia, Vojkova cesta 1b, SI-1000 Ljubljana, Slovenia; E-mail: petra.souvent@gov.si, zlatko.mikulic@gov.si, miso.anjelov@gov.si, vlado.savic@gov.si Received: July 31, 2007 Accepted: October 4, 2007 Abstract: Five out of 21 groundwater bodies (GWBs), which have been delineated in Slovenia with regard to the EU Water Framework Directive (WFD), comprehend mostly alluvial high permeability aquifers. They cover approximately 10 % of the country area but contribute to about 50 % of all groundwater abstraction and to about 40 % of all drinking water to the Slovenian water supply system. The existing groundwater quantity monitoring network (GWQMN) mostly covers the areas within the GWBs which are of drinking water pumping interest. To meet all the requirements of WFD and to enable reliable assessments of the quantity status of GWBs, the existing old network has been redesigned with the help of GIS tools with the great emphasis on hydrogeological, geological and pedological characteristic of GWB. Described method of network design leads to 36 new monitoring sites on GWBs with alluvial aquifers. Redesigned national GWQMN provides better coverage of spatial differences within GWBs and shall provide data needed to better understand the groundwater regime in the GWBs. Izvleček: Za potrebe ocenjevanja stanja podzemnih voda in njihovega upravljanja je bilo v Sloveniji določenih 21 vodnih teles podzemne vode v skladu z Vodno direktivo. Pet vodnih teles podzemne vode, s pretežno visoko prepustnimi aluvialnimi vodonosniki, se razprostira na približno 10 % Slovenije, vendar se iz njih črpa okoli 50 % podzemne vode, oziroma 40 % vse pitne vode. Obstoječa državna mreža za spremljanje količin podzemne vode je do sedaj dobro pokrivala le področja, ki so pomembna z vidika vo-dooskrbe. Glede na nove prostorske enote ocenjevanja stanja voda je bilo potrebno državno mrežo za spremljanje količin podzemnih vod izpopolniti in zadovoljiti zahtevam metodologije ocenjevanja količinskega stanja. 236 SoUVENT, P., et.al. Uporabili smo prostorsko analitično metodologijo v GIS tehnologiji, ki je upoštevala hidrogeološko, geološko in pedološko homogenost danega ozemlja ter pri analiziranju prostora upoštevali različne tipe in režime varovanja. Z opisano metodo smo določili 36 novih merilnih mest na vodnih telesih s pretežno aluvialnimi vodonosniki. Izpopolnjena državna mreža za spremljanje količin podzemne vode nudi boljšo pokritost prostorsko in hidrološko različnih območij znotraj vodnega telesa in zagotavlja boljše razumevanje režima podzemne vode v danem vodnem telesu. Key words: groundwater, groundwater monitoring, groundwater monitoring network design, groundwater quantity, alluvial aquifer Ključne besede: podzemna voda, monitoring podzemne vode, načrtovanje mreže, količina podzemne vode, aluvialni vodonosnik Introduction Underthe EUWaterFrameworkDirective[1], a total of 21 groundwater bodies[2] have been delineated in Slovenia, with mostly karst and fissured porosity aquifers (68.9 %), followed by aquifers with intergranu-lar porosity (26.2 %) and special case of aquifers in napped tectonic structures and aquitards (4.9 %). Five GWBs (Figure 1) with mostly alluvial, high permeability aquifers are of special interest in this study as they contribute about a half of Slovenian abstracted groundwater, but their area cover just approximately 10 % of the country. In the year 2005, about 467x106 m3 of groundwater was available and 116.4*106 m3 abstracted from these GWBs. The first groundwater quantity monitoring network (GWQMN) in Slovenia was established in the year 1952 when observers started GW level measurements in 20 private wells. This was the beginning of the national monitoring in the alluvial aquifers. The number of monitoring sites has changed with the time with regard to the Slovenian water policy. The maximum was reached in the year 1960 with 244 monitoring sites (Figure 2). In the year 2007 the national GWQMN has 128 monitoring sites in the alluvial aquifers within 5 GWBs. So far, the existing groundwater quantity monitoring network mostly covered the areas within the GWBs which are of drinking water supply interest. To meet all the needs of WFD and to enable reliable assessments of the quantity status of GWBs, the existing network has been redesigned using GIS tools[3]. Figure 1. GWBs with mostly alluvial high permeability aquifers Slika 1. Vodna telesa podzemne vode (VTPodV) s pretežno aluvialnimi vodonosniki Figure 2. Development of the national groundwater quantity monitoring network in Slovenia Slika 2. Razvoj državne mreže za spremljanje količin podzemne vode Designing the groundwater quantity monitoring network The leading idea was to divide the area of GWBs into logical units according to the hydrogeological, geological and pedologi-cal characteristics (Figure 3) and afterwards to add areas protected by law. These protected areas include Natura 2000 sites established under the EU Habitats Directive (92/43/EEC)[4] and the EU Birds Directive (79/409/EEC)[5] as well as Drinking Water Protected Areas established under Article 7[6] of the WFD. Hydrogeological spatial data layer comprises all known hydrogeologically distinct units within specific GWB and distinguish between different hydrological regimes, such as: areas with direct infiltration of rainfall into alluvial aquifer were separated from the areas fed by the runoff from the hills, as well as recharge from rivers and inflow from other aquifer systems. Perched aquifers were defined and delineated too. They overlay the lover hydrogeological unit. On Figure 4, an example of hydro-geologically distinct units is presented for the GWB Mura valley. For each GWB pertaining catchment area was determined. Catchment area was divided in sub-catchment areas that represent catchments for each logically separated spatial unit. On Figure 5, as best and clear example among alluvial GWBs, a catchment area and its sub-catchment areas are presented for the GWB Savinja valley. In the case of trans-boundary GWB, the areas of groundwater inflow from another country and groundwater outflow from Slovenia were separated too. Figure 3. Concept of joining spatial data layers (SDL) into one logical subsystem of GWB Slika 3. Koncept združitve prostorskih podatkovnih slojev (PPS) v homogeni podsistem vodnega telesa Figure 4. Hydrogeologically distinct units within GWB Mura valley Slika 4. Hidrogeološko različna območja znotraj mej VTPodV Murska kotlina Figure 5. Catchment area and sub-catchments areas for the GWB Savinja valley Slika 5. Zaledje in podenota zaledja prikazana za primer VTPodV Savinjska kotlina The geological spatial data layer was constructed with the help of geological maps[7] (1:100000) and lithological cross sections, if available. In this layer, each GWB was divided into geological units according to the surface geology (Figure 6). Lithological cross sections were used for better understanding of the sub-surface geology. Pedological spatial data layer consists of areas defined due to soil characteristic (Figure 7). The source of information in this process were the general digital pedo-logical map of Slovenia[8] with soil types, map of mean soil depth[8] and map of mean textural soil classes in Slovenia[8]. All three spatial data layers were combined into one composite layer (Figure 3) with GWB units, representing areas with a similar hydrogeological regime, geology and pedology (Figure 8). Such an analysis of GWBs has enabled selection of new monitoring sites by the principle: each logically separated spatial GWB unit should have at least one groundwater monitoring site. Within these units, protected areas were also separated, represented by one monitoring site as a rule. In the areas with no hydrological data of groundwater monitoring, the area of the groundwater body was divided due to aquifer systems defined by Geological Survey of Slovenia[9], and the density of network was adjusted accordingly. Figure 6. Geological units within GWB Mura valley Slika 6. Geološke enote znotraj mej VTPodV Murska kotlina Figure 7. Soil Characteristics within GWB Mura valley Slika 7. Tipi tal znotraj mej VTPodV Murska kotlina Figure 8. Spatial data layer with the GWB units (13) indicating the similar hy-drological regime, geology and pedology (example for GWB Mura valley) Slika 8. Prostorski podatkovni sloj z območji (13), kjer je podoben hidrološki režim, geologija in pedologija (primer za VTpodV Murska kotlina) Table 1. Main alluvial GWBs (Figure 1) with existing and new monitoring sites Tabela 1. VTPodV s pretežno aluvialnimi vodonosniki (slika 1) z obstoječimi in novimi merilnimi mesti The Sava valley & Ljubljana moor The Mura valley The Drava valley The Savinja valley The Krško valley Area in km2 774 591 429 109 97 Number of areas with the similar hydrological regime, geology and pedology (GWB units) 28 13 12 7 6 Number of existing monitoring sites (GW monitoring program 2007) 41 24 18 19 26 Number of new monitoring sites 28 1 3 2 2 Total number of monitoring sites 69 25 21 21 28 Results and discussion Checking the existing GWQMN with the help of described method has shown that majority of the existing monitoring sites within relevant GWB fits well into this new concept of network design. Anyhow, redesign of existing national GWQMN still led to certain number of new monitoring sites (Table 1) which will be added to the GWQMN. On Figure 9, for example, the existing and planned monitoring sites are presented for the GWB Sava valley and Ljubljana moor. Following the design study phase in the office, field inspection has begun and is still in progress, with the purpose to confirm or to reject the chosen new locations. The GWQMN will be completed with the new monitoring sites gradually, till the year 2013, within the project: "Upgrading of hydro-meteorological system for monitoring and analysis of waters in Slovenia" [10]. Conclusions Described method of network design has enabled easier selection of monitoring sites and has facilitated the set up of better GWQMN. Redesigned national GWQMN shall provide better data needed to under- stand groundwater regime in the GWBs, enable reliable assessments of the quantitative status of a GWB, shall facilitate the national groundwater quality monitoring network redesign and offer additional data for a modeling of groundwater flow in the alluvial aquifers. Figure 9. Existing (41) and planned (28) monitoring sites for the GWB Sava valley and Ljubljana moor Slika 9. Obstoječa (41) in planirana (28) merilna mesta na VTPodV Savska kotlina in Ljubljansko barje 244 SoUVENT, P., et.al. Povzetki Načrtovanje državne mreže za spremljanje količin podzemne vode na vodnih telesih podzemne vode z aluvialnimi vodonosniki Državna mreža za spremljanje količin podzemne vode na vodnih telesih podzemne vode s pretežno aluvialnimi vodonosniki (slika 1), vključuje večinoma obstoječe objekte, kot so: piezometri, vrtani vodnjaki in kopani vaški vodnjaki, ki prvotno niso bili namenjeni za spremljanje globine do podzemne vode v sklopu državne mreže. Državna mreža je bila v preteklosti usmerjena predvsem na območja, ki so bila pomembna za vodooskrbo. S sprejetjem Evropske vodne direktive - VD (EU Water Framework Directive (WFD)) in z definiranjem 21 vodnih teles podzemne vode na območju Slovenije, se je koncept za spremljanje količin podzemne vode prilagodil VD. Da bi zadostili potrebam VD, mora Slovenija spremljati in oceniti količinski status vodnih teles v skladu z zahtevami VD in z mrežo optimalno pokriti celotno vodno telo podzemne vode. Tako smo z novim pristopom načrtovanja državne mreže za spremljanje količin podzemne vode na vodnih telesih s pretežno aluvialnimi vodonosniki preverili, kako dobra je pokritost vodnih teles z dosedanjo mrežo in v primeru nezadostne pokritosti optimalno pokrili območja znotraj vodnih teles z novimi merilnimi mesti. Pri tem smo uporabili prostorsko analitično metodologijo v GIS tehnologiji, ki je upoštevala hidrogeološko, geološko in pedološko homogenost danega ozemlja ter pri analizi- ranju prostora upoštevali različne tipe in režime varovanja. Vodilna ideja metodologije je bila razdeliti območja vodnih teles na logične enote glede na hidrogeološke, geološke in pedološke karakteristike danega ozemlja. Tako smo za vsako vodno telo s pretežno aluvialnimi vodonosniki (za 5 teles - slika 1) kreirali tri prostorske podatkovne sloje, ki smo jih potem združili v skupen prostorski podatkovni sloj: • Hidrogeološki prostorski podatkovni sloj, • Geološki prostorski podatkovni sloj, • Pedološki prostorski podatkovni sloj. Hidrogeološki prostorski podatkovni sloj Hidrogeološki prostorski podatkovni sloj vključuje vsa znana hidrogeološko različna območja znotraj danega vodnega telesa in tako razlikuje med različnimi hidrološkimi režimi. Izdvojena so bila tudi območja z visečo podtalnico. Območja s prevladujočo direktno infiltracijo padavin v aluvialni vodonosnik smo tako ločili od območij, ki se večinoma napajajo iz zaledja. Izdvojili smo območja, kjer reka napaja vodono-snik in območja, kjer je dotok podzemne vode iz drugih vodonosnih sistemov. Slika 4 prikazuje hidrogeološke enote znotraj VTPodV Murska kotlina. Za vsako vodno telo smo definirali odgovarjajoče zaledje, ki je razdeljeno na več pod-zaledij. Vsako pod-zaledje odgovarja enemu izdvojenemu območju znotraj vodnega telesa. Na sliki 5 je primer zaledja in pod-enote zaledja prikazan za VTPodV Savinjska kotlina. Ločili smo tudi cone dotoka podzemne vode iz sosednjih držav ter cone iztoka podzemne vode iz Slovenije. Geološki prostorski podatkovni sloj Geološki prostorski podatkovni sloj je nastal na podlagi osnovne Geološke karte, znanih litoloških presekov vodnih teles in litologije pridobljene iz vrtin iz baz Geo-ZS in Oddelka za hidrologijo podzemnih voda. V tem podatkovnem sloju je vodno telo razdeljeno na območja glede na geologijo na površju vodnega telesa. Litološke preseke smo uporabili za boljše razumevanje geologije pod površjem. Na sliki 6 so prikazane geološke enote znotraj mej VT-PodV Murska kotlina. Pedološki prostorski podatkovni sloj Pedološki prostorski podatkovni sloj je sestavljen iz območij, ki smo jih določili glede na karakteristike tal določenega vodnega telesa. Podatke o tipih tal smo pridobili iz osnovne pedološke karte Slovenije, karte o povprečni globini tal v Sloveniji ter karte o povprečnem teksturnem razredu tal v Sloveniji. Na sliki 7 so prikazani tipi tal znotraj mej VTPodV Murska kotlina. Združitev vseh treh prostorskih podatkovnih slojev Vsi trije podatkovni sloji so bili združeni v en prostorski sloj, ki predstavlja območja s podobnim hidrogeološkim režimom, geologijo in pedologijo. Združen prostorski podatkovni sloj je prikazan za primer VTPodV Murska kotlina na sliki 8. Takšen pristop k izpopolnitvi mreže nam je omogočil preveritev obstoječe mreže in izbor novih merilnih mest oz. lokacij po načelu: vsaka logično izdvojena enota na vodnem telesu mora biti pokrita z vsaj enim merilnim mestom. Na območjih, na katerih ne razpolagamo s hidrogeološkimi podatki, so bila območja znotraj vodnega telesa izdvojena na podlagi vodonosnih sistemov, ki jih je določil GeoZS, temu primerno je bila prilagojena gostota mreže. Preveritev državne mreže za spremljanje količin podzemne vode na vodnih telesih z opisano metodo je pokazala, da se večina obstoječih merilnih mest znotraj danega vodnega telesa dobro vklaplja v opisani koncept izpopolnitve mreže. Opisana metoda je pripeljala do 36 novih lokacij na petih vodnih telesih s pretežno aluvialnimi vodonosniki. Po končanem kabinetnem delu smo začeli s terenskimi ogledi novih lokacij z namenom, da potrdimo ali ovrže-mo le-te. Opisana metoda omogoča lažjo izbiro novih lokacij oz. merilnih mest in olajšuje postavitev optimalne državne mreže za spremljanje količin podzemne vode na vodnih telesih s pretežno aluvialnimi vodo-nosniki. Takšna mreža nam bo zagotavljala bolj kakovostne podatke za poznavanje hidroloških režimov na danih vodnih telesih in bo omogočala zanesljivo oceno količinskega stanja vodnih teles. Olajšala bo izpopolnitev državne mreže za spremljanje kvalitete podzemne vode in zagotovila dodatne podatke, ki jih potrebujemo za modeliranje toka podzemne vode v aluvialnih vodonosnikih. References [1] [2] [3] [4] [5] [6] Directive 2000/60/EC of the European Parliament and of the Council (WFD). Official Journal of the European Communities. 2000, 72 p. URL RS 63/05 (2005): Pravilnik o določitvi vodnih teles podzemnih voda (Rules on determining water bodies of groundwater). souvent, P., Gale, u., Mikulič, Z., And-jelov, m., Trišič, N., Savič, V. (2007): Strokovna izhodišča za izpopolnitev merilne mreže za spremljanje količin podzemne vode. Interno gradivo Sektorja za hidrologijo, (Hydrogeological Guidelines for Upgrading Groundwater Quantity Monitoring Network), 104 str. Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora. Council Directive 79/409/EEC of 2 April 1979 on the conservation of wild birds. Article 7 of the WFD (2000): Waters used for the abstraction of drinking water. Official Journal of the European Communities. p. 12. [7] [8] [9] [10] Geological map of Slovenia (23 separate sheets) in GIS environment (2003). Geological survey of Slovenia. Soil data of Slovenia (2007), Centre for Soil and Environmental Sciences of Biotechnical Faculty. Dostopno na svetovnem spletu http://www.bf.uni-lj.si/cpvo/Novo/main_PodatkiTalSlo-venije.htm. Geološki zavod Slovenije (2004): Nacionalna baza hidrogeoloških podatkov za opredelitev teles podzemne vode Republike Slovenije. Sklepno poročilo 3. faze. (Geological Survey of Slovenia (2004): National base of hydrogeological data for groundwater body determination in Slovenia). Agencija RS za okolje (2006): Projekt: Nadgradnja sistema za spremljanje in analiziranje stanja vodnega okolja v Sloveniji (SSSV). (Environmental Agency of the Republic of Slovenia (2006): Project: Upgrading of hydro-meteorological system for monitoring and analysis of waters in Slovenia). A contribution to construction monitoring with simultaneous application of various types of observations Prispevek k spremljanju objektov s simultanimi meritvami različnih tipov Milivoj Vulić 1, Gregor Uranjek 2 1 University of Ljubljana, Faculty of Natural sciences and Engineering, Department of Geo-technology and Mining Engineering, Aškerčeva cesta 12, SI-1000 Ljubljana, Slovenia; E-mail: milivoj.vulic@ntf.uni-lj.si 2 Premogovnik Velenje d.d., Partizanska cesta 78, 3320 Velenje, Slovenia; E-mail: gregor.uranjek@rlv.si Received: September 2, 2007 Accepted: September 25, 2007 Abstract: The presented observations, adjustment and analysis of the spatial het-erogeous local network initial epoch will serve together with following epochs for object's characteristic points mutually spatial position monitoring. Spatial heterogeous local network is observed with simultaneous observations of various types. Observations between characteristic points could not be applied. From the initial epoch results is concluded that on the base of precision estimations of slope distances between object's characteristic points is expected that will be possible to monitor slope distance changes larger than 10 mm in any direction in space (at т = 2, the probability is 95.45 %). If the most favorable condition are considered, it will be possible to monitor slope distance changes larger than 3 mm (at т = 2, the probability is 95.45 %). Izvleček: Predstavljena je izmera, izravnava in analiza začetne terminske izmere prostorske heterogene merske mreže, ki bo skupaj z naslednjimi termin-skimi izmerami služila za analizo spremljanja medsebojnih prostorskih položajev karakterističnih točk objektov. Heterogena prostorska mreža je merjena s simultanimi meritvami različnih tipov. Meritve poševnih razdalj med karakterističnimi točkami niso bile mogoče. Iz rezultatov začetne terminske izmere je zakjučeno, da se bodo lahko na osnovi ocen natančnosti poševnih razdalj med karakterističnimi točkami spremljale spremembe poševnih razdalj večje kot 10 mm v poljubni smeri v prostoru pri т = 2 (verjetnost je 95,45 %). Ob upoštevanju najugodnejših primerov pa se pričakuje, da se bodo lahko zaznale spremembe poševnih razdalj večje od 3 mm pri т = 2 (verjetnost je 95,45 %). Key words: spatial heterogeneous networks, 3D adjustment, estimation of the precision, monitoring of mutual spatial relations, characteristic points, confidence pedaloid (surface) Ključne besede: prostorska heterogena merska mreža, 3D izravnava, ocena natančnosti, spremljanje medsebojnih prostorskih položajev, spremljanje medsebojnih prostorskih relacij, karakteristčne točke, pedaloid (ploskev) pogreškov Introduction The discussed example deals with simultaneous observations and simultaneous adjustment of spatial heterogeneous local network. The purpose of the local network will be monitoring of mutual spatial positions of characteristic points, with a possibility of constraining local network into the existing network. Observations between object's characteristic points could not be applied. Slope distances between characteristic points are afterwards determined from adjusted characteristic points spatial coordinates. Estimation of slope distances precision is based on variance-covariance matrix of unknowns £ü of the observed network which is the result of the adjustment. For the construction (pillars) monitoring purpose four characteristic points (one per pillar) and two auxiliary points in pillars proximity have been reconnaissanced and materialized. Characteristic points are observed from auxiliary points which are observed from existing network points. Observation method of heterogeneous local network Heterogeneous observation system is combined from different types of observation systems. Heterogeneous observation system contains observed points, observations, network adjustment and results interpretation. Regardless the observations types and observation systems, respectively, which are containing heterogeneous observation system all observations, are simultaneously adjusted. Simultaneous observations of heterogeneous local network contain three observa- tion systems: - baselines of static DGPS observations (Differential Global Positioning System), - height differences of differential leveling, - microtriangulation and microtrilatera-tion: - horizontal directions, - zenith distances, - slope distances. From existing network points (XI/A1 and X/5) the auxiliary points (Pom1 and Pom2) are observed with baselines of DGPS observation and height differences of differ- RMZ-M&G 2007, 54 ential leveling and from auxiliary points characteristic points (STk1, STk2, STk3 and STk4) are observed with combined resections (Figure 1) (horizontal directions, zenith distances and slope distances) using the sets of angles method. The results of local network observation are most probable values and a priori precision estimations of individual observations. Figure 1. Heterogeneous local network Slika 1. Lokalna heterogena merska mreža Adjustment of local network The entering adjustment data are known points' coordinates of the existing network and the approximate coordinates of characteristic and auxiliary points and most probable values and a priori precision estimations of individual observations. Adjustment strategy of local network The simultaneous adjustment procedure of terrestrial and GPS observations is realized in three steps: - observation testing with adjustment of inner constrained or minimally constrained networks upon individual observation types or observation systems, - quality known points control of the existing network which is illustrated with combined adjustment comparison (GPS network and leveling network) in minimally constrained network and fully constrained network in which the known points are datum, - combined adjustment of terrestrial and GPS observations. Adjustment of heterogeneous local network with programme package Leica Geo Office 5.0 Local network, which is observed with terrestrial and GPS observations, is adjusted as spatial (3D) network with or-thometric heights in programme package Leica Geo Office 5.0 (module Adjustment). Leica Geo Office 5.0 in module Adjustment is using processing kernel MOVE3 3.4 of well known programme for network adjustment MOVE3. Module Adjustment is one of the programme package Leica Geo Office 5.0 modules and it is suitible for the design, adjustment and quality control of 3D, 2D and 1D measuring networks. 3D model for combined adjustment of terrestrial and GPS observations (Local geodetic) in the programme package Leica Geo Office 5.0, is in ellipsoidal coordinates (ф, X, h) in local coordinate system. This kind of 3D model, which is implemented in programme package Leica Geo Office 5.0, has following advantages (Boekelo, 1996): • The mathematical model is "truly" 3D; designed to model 3D reality (in stead of the 2D map), it complies with the modern surveying needs. • The model does not require reductions to sea level or to the horizontal plane, nor corrections for earth curvature or for the projection. • As mapping/projection is an auxiliary process there is no model-constraint limiting the network size. • The model is best suited for the combination of GPS and terrestrial measurements. • Original observations are tested (in stead of derivatives) using an uncompromised statistical model. In programme package Leica Geo Office 5.0 the precision estimation of 3D position is visualized in two parts so that the standard deviation of plane position (X,Y) is presented with confidence ellipse, and standard deviation of height (H) is presented separately with a bar in the same scale as confidence ellipse (Figures from 2 to 5). Precision estimation of observations is presented only with relative confidence ellipse (2D). Observation testing In order to test observations regarding to blunders (gross errors), the observation systems are adjusted separately in inner constrained networks or minimally constrained networks. With this procedure the known points influence is unabled. All observations have been tested with standardized residuals with observations a priori variances (Vulić, 2005/2006): (1) V ni - standardized residual with a priori observation variances V - observation residual J - a priori observation variance Separately observations have been tested with statistical tests F-test (global test) and W-test (datasnooping test), which are programme package Leica Geo Office 5.0 tools. The results of all observation tests show that observations are blunders free. Quality control of known points Known points acquired data unfortunately did not include a posteriori precision estimation of known points. The known points influence on a posteriori precision estimation of auxiliary points is illustrated with combined network (DGPS baselines and height differential leveling differences) adjustments comparison in minimally constrained network and fully constrained net- work in which the known points are datum. The a posteriori precision estimation of auxiliary points at minimally constrained network adjustment is influenced only by observations incompatibility (Figure 2) and the a posteriori precision estimation of auxiliary points at fully constrained network adjustment is influenced with observations incompatibility and mutual position of known points quality (Figure 3). Combined adjustment of terrestrial and gps observations Objects will be monitored with slope distances changes between characteristic points. For that matter the slope distances precision is important. For precise slope distances determining the quality of auxiliary points mutual position is important. From known points quality control is concluded, that the known points are determined with centimeter's precision at best. Observation testing show that the characteristic points can be determine with millimeter's precision by combined resections from auxiliary points. From known points quality control and observation testing is obvious that carrying errors from known points to local network are not reasonable. Because of the stated findings the simultaneous adjustment of terrestrial and GPS observations is executed in two steps. In first step the datums in adjustment are existing network points (Figure 4). With first step the auxiliary points mutual position is determined. In second step the datums in adjustment are auxiliary points adjusted coordinates determined in first step. With second step the adjusted (Figure 5) characteristic points coordinates and variance-covariance matrix of unknowns is determined. 1$*0Г«ШШГЁ 55'ог«.ад«ГЕ 15"ог«.вооагЕ ____Là. k ^ггплшги 10 ШХГ P« / ^ / / 4 H 1VC Ù/-.............. Ii2<&9№ГН л-ггоеоооагк -ИИЙ*- ^ ^ 0001 in ft 0001* * < ^i i—— > »Vv.ew liOP^P 4TPS-P š Я-.ТУ5- 'P Adjurei, , | Surfe ?Ал1сп ар« См» Figure 2. Adjustment of DGPS baselines and differential leveling height differences in minimally constrained network Slika 2. Izravnava minimalno vpete mreže baznih vektorjev in višinskih razlik geometričnega nivelmana Figure 3. Adjustment of DGPS baselines and differential leveling height differences in fully constrained network Slika 3. Izravnava vpete mreže baznih vektorjev in višinskih razlik geometričnega nivelmana Figure 4. First step of terrestrial and GPS observations simultaneous adjustment Slika 4. Prvi korak skupne izravnave terestričnih in GPS opazovanj S£320b SGÈSDm ШХш 5064«» ШШа Чл ... ft" ___ t ' ....../.....\ sS^ j / / / И j " 7 \ f \ / I 136*201» 136100« è. Ш .....4.....fe... ^ rt ___ ^ Attn г. С 0(01 ■ I Ы. ÜGFSP £ Trap ъ LMt JftAi^t- | "fi Poi.. &Suni ? Arten фйав.. £> Cwto. Figure 5. Second step of terrestrial and GPS observations simultaneous adjustment Slika 5. Drugi korak skupne izravnave terestričnih in GPS opazovanj Determination and precision estimation of slope distances between characteristic points At network adjustment the variance-covariance matrix Eü elements are saved in separated ASCII file (AdjVar2). Adjusted characteristic points spatial coordinates are determined with 3D adjustment model in ellipsoidal coordinates (ф, X, h), which are then projected on a plane (Gauss-Krüger projection). Heights are defined with orthometric heights. Characteristic points plane coordinates (Y X) and ortho-metric heights (H) are adopted in further calculations as spatial coordinates (Y, X, H) because of the small local network dimensions (Figure 1). From adjusted characteristic points coordinates are determined slope distances d,lapiii between characteristic points with expres- (2) Index i is for slope distance starting point and index j is for slope distance finishing point. A posteriori precision estimation of slope distances between characteristic points is acquired from variance-covariance matrix of unknowns E (Figure 6) which is adjustment product (simultaneous adjustment of all observations). Variance-covariance matrix E is containing information about a posteriori precision estimation of all points' spatial coordinates (variances) which are taking part in adjustment and interdependence between all points' spatial coordinates (covariances). Upon our suggestion1 the programme package Leica Geo Office producer has add variance-covariance matrix £д,у between module Adjustment results in version 5.0. From variance-covariance matrix (Figure 6) submatrixes (3x3) the covari-ance matrixes E for each slope distance are composed, for which the precision estimation is wanted. The belonging slope distance covariance matrix is then determine with taking into consideration the variance-covariance propagation law for random variables linear functions (Vulić , 706V - J(y ' 1 ■[-I ']■ L t E- - I хд„ Л if a;,. (3) Jij - the Jacobian matrix for slope distance's dsbpe .. components functions .Sii ,S.v.i.»E*,j - submatrixes(3x3) of covariance matrix £ of parameters ij - covariance matrix of slope dis- *Дif tance between characteristic points i and j After all slope distances covariance matrixes determination it is proceeted to confidence surface's defining elements 1 We purchased programme package Leica Geo Office 4.0 in which the complete cofactors matrix Q ) extraction is not supported. If we have to determine cofactors matrix Q.u by our selves (as we did before purchase) the programme package is unnecessary because we must execute complete adjustment to determine cofactors matrix Q u which is one of the adjustment results. After contact with producer's technical support, they added the complete variance-covariance matrix ^ :.T between module Adjustment results in version 5.0 and they upgraded our programme package to Leica Geo Office 5.0. я S) -я R ж » - - = - - - - « ■= m - 1 i Щ S i 1 ! 111 R - A - o - m - = - - - Й- i Si K i-i « - CP- - = o - о = = O S ri S. S 11 cJ № 1- = = - = - - ■=> •> <• - = - = - ■= 1 ^ r" " ■ - 5 1 s È n - - O - O o «s» o o « - о o O § 5. i g Й OJ S X = - = - = *» = - = = - -- и S 1 1 e S 1 = = = s 1 1 i s 5 i 1 1 1 Э s s S —Г SD - m 3 <» = » m = I i 1 s 1 s 1 1 1 1 11 » = m : Й X = = = - - ! ; s § m S 1 1 I 1 Щ s £ 1 11 - = = = g Ä ™ - - = s ! 1 m й s tà 1 S 1 1 11 ОО № § S 1 s é = - - = a IH » - - ! 1 s s 1 s i 3 i ri 11 » 1 s K -t э g - : = = Щ i - - i i 1 1 s g : ■ Щ В j 1 1 r~i = - - - g Ж - - - = - i s 5 Š 111 orf ^T " U-r -- e L'J £4 s fi 1 s Щ s 1 a> nf = = - - 1 - » O o 1 s S s 1 s i e 1 Б i s ::: Ö = i •a £ X at - = « = - 1 s 3 1 1 tè 1 s $ 1 S s L . 1 s a 1 s ? • = m - - m o «s - = - = = = - - - - - = - - 3 - « » - - o