Original scientific paper	Received: October 3, 2014
Accepted: October 15, 2014
Ammonites from Mt Kobla (Julian Alps, NW Slovenia) and their significance for precise dating of Pliensbachian tectono-sedimentary event
Amoniti s Koble (Julijske Alpe, SZ Slovenija) in njihov pomen pri natančnem datiranju pliensbachijskega tektonsko-sedimentarnega dogodka
Boštjan Rožič1, *, Federico Venturi2, Andrej Šmuc1
department of Geology, Faculty for Natural Sciences and Engineering, University of Ljubljana, Privoz 11, 1000 Ljubljana, Slovenia 2University of Perugia, Earth Science Department, Piazza Università 1, 06123 Perugia, Italy Corresponding author. E-mail: bostjan.rozic@ntf.uni-lj.si
Abstract
Although ammonites serve as index fossils in the Jurassic, their discovery in the area of present-day Slovenia are rare, with only three locations having been studied in greater detail. Here we presented ammonites from a newly discovered site at Mt Kobla on the eastern Bohinj Range. The site is located at the very top of the Kobla skiing ground, where 250 m of Lower Jurassic limestone of the Julian Carbonate Platform crop out. The succession begins with peloidal/ooidal limestone which upwards passes into bioclastic limestone that alternates in laminas and beds with crinoidal limestone. In the topmost part, limestone breccia is interbedded and neptunian dykes cut the succession. Just below the breccia bed, ammonites were retrieved and genera Canavaria and Neolioceratoides were identified which indicate an Upper Pliensbachian (?upper Domerian) age. The platform limestones are overlain with basinal strata with internal unconformity. The overall succession records a progressive deepening of the sedimentary environment that culminated in the Upper Pliensbachian and was caused by a regionally recognized, but relatively poorly-dated episode of accelerated subsidence. The Mt Kobla succession correlates well with Mt Mangart and Mt Bohinj successions, which are paleogeographically considered as marginal locations within the Julian Carbonate Platform. Ammonite dating encourages further detailed sedimentary studies of the Mt Kobla succession.
Key words: ammonites, Julian Carbonate Platform, Pliensbachian, Southern Alps, platform drowning, subsidence, tectono--sedimentary event
Izvleček
Čeprav so amoniti vodilni fosili v juri, so njihove najdbe na območju današnje Slovenije zelo redke. Le tri nahajališča so bila natančneje preučena, in sicer spodnjejursko, najverjetneje pli-ensbachijsko, v Bohinjski dolini, Toarcijsko na Begunjščici in zgornjejursko v Dolini Triglavskih jezer. Med detajlnim geološkim kartiranjem gore Koble, ki se nahaja v vzhodnemu delu Bohinjskega grebena, je bilo odkrito novo najdišče. Nahaja se na samemu vrhu smučišča Kobla, kjer je razgaljeno 250 m debelo zaporedje spodnjejurskih apnencev Julijske karbonatne platforme. Začenja se s peloidno/ooidnim apnencem v skupni debelini 170 m. Lepo je razgaljenih le vrhnjih 60 m zaporedja. Navzgor preide v bioklastični apnenec, ki se v laminah in plasteh menjava s krinoidnim apnencem. V vrhnjem delu celotnega platformskega zaporedja se začnejo pojavljati neptunski dajki in plasti apnenčeve breče. Amoniti so bili najdeni tik pod debelo plastjo breče, ki je interstratificirana v vrhnjem delu zaporedja. Med številno favno smo izbrali najbolje ohranjene primerke in določena sta bila rodova Canavaria in Neolioceratoides, katerih sočasno pojavljanje kaže na zgornji pliensbachij (?zgornji do-merij). Platformski apnenci so prekriti z bazenskimi sediment, ki vsebujejo stratigrafsko vrzel. Celotno opisano zaporedje označuje progresivno poglabljanje sedimentacijskega okolja, ki ga je v zgornjem pliensbachiju pospešila regionalno prepoznana, a relativno slabo datirana epizoda ekstenzijske tektonike. Zaporedje na Kobli je primerljivo z lokacijami na območju Julijske karbonatne platforme, ki paleogeografsko spadajo v robne dele Julijske karbonatne platforme. Amonitne datacije spodbujajo nadaljnje detajlne sedimentološke raziskave platformskega zaporedja na Kobli.
Ključne besede: amoniti, Julijska karbonatna platform, pliens-bachij, Južne Alpe, potopitev platform, pogrezanje, tektonsko--sedimentarni dogodek
Introduction
The Permian/Triassic boundary extinction events drastically decimated Paleozoic life, leaving few survivors to evolve into the Meso-zoic era[1 and references therein]. One of the most interesting and, due to their spiral molds and spectacular suture patterns, attractive groups of fossils that dominated Mesozoic sea life was ammonites. They show rapid speciation, are regularly preserved, and broadly distributed, which promotes them as one of the most valuable index fossils. Although ammonites are common in the Mesozoic of the Tethys Realm, their discovery in the area of present-day Slovenia is sporadic. The first representatives of the Ammonoidea subclassis are known from the Upper Carboniferous and Lower Permian of the Southern Karavanke Mountains[2]. The richest period is the Triassic, with well-known Late Anisian locations at the village of Bučka near Novo Mesto[3] or Hrastenice Quarry near Polhov Gradec[4], as well as the Ladinian and Carnian of the Mežica Mine and Mt. Peca in the Northern Karavanke Mountains, Idrija area and Mt Triglav[5-8] and others[for the review see 9 10]. Although the Jurassic is the period of prominent ammonite diversification, only three sites have been extensively studied, the first being Pliensbachian Bohinj Valley[11], the second being Toarcian Mt Begunščica[12], and the third the Upper Jurassic Triglav Lakes Valley[13, 14]. Ammonites from the first site were collected from Hierlatz limestone[11, 15], a facies otherwise known from the Northern Calcareous Alps, where it is described as relatively shallow, Sine-murian to the Pliensbachian hemipelagic limestone, deposited on top of morphological highs formed after the drowning of the carbonate platform at the end of the Triassic[16]. Other two sites were excavated from Ammonitico Rosso - type limestone[17- 19], a facies characteristic of the submarine plateaus of the Jurassic Adria passive margin[20-24]. Just a few other Jurassic specimens are reported, mostly from the Julian Alps[10]. Sporadic Upper Cretaceous ammonites are known from Komen and Tomaj limestones from the Karst Plateau[25]. The rare occurrence of Jurassic ammonites is attributed to specific sedimentary environments that persisted in the region during the Jurassic.
Shallow water, high energy and flat-topped carbonate platforms were interspaced by deep basins[26, 27], whereas the condensed limestone of the submarine plateaus, i.e., potential ammonite-bearing facies, is mostly eroded and outcrops in just a few places[28, 17]. Consequently, the discovery of new Jurassic ammonites is of special importance for Slovenian paleontology and biostratigraphy. In the present paper, we present such a site from the top of the Kobla skiing-ground found during the detailed geological mapping of the area. The main goals of this paper are to A] describe the geological setting of the site, B] provide a basic sedimentary analysis of the strata with ammonites, and C] define the biostratigraphy of the fossil assemblage.
Previous work and paleogeography
Ammonites were collected from a site located at the top of the Kobla skiing ground in the eastern part of the Bohinj Range, which forms the southern orographic boundary of the Julian Alps (Figure 1]. The oldest geological record from Mt Kobla comes from a sketch of the iron mine that was owned by Baron Žiga Zois and made by Polc in years 1788-1790 (Schmidt Goran, pers. comm.]. Extensive geological research was made during the construction of the railway tunnel which crosses the Bohinj Range directly below Mt Kobla. Kossmat[29] summarized the data, presented the structure and lithostratigraphic division, and elaborated the geological map (1 : 75 000] of the wider area. The author outlined that the northern slopes of Mt Kobla consist of Late Triassic and Early Jurassic carbonates overlain by Oligocene clastics, whereas the southern slopes consist of thin bedded, often cherty strata. During the work on a Basic Geological Map of Yugoslavia (sheet Tolmin] Buser[15, 28] defined the pa-leogeographic affinities of these successions: northern, i.e., carbonate succession sedimented on the Julian Carbonate Platform (JCP], whereas southern developments were deposited in the Slovenian Basin (SB][15, 30]. Both paleogeo-graphic units originated in the Middle Triassic after disintegration of the Slovenian Carbonate Platform[26, 31] which was related to the rifting of
193
the Meliata Ocean[32]. The JCP disintegrated and drowned in the Middle Jurassic and turned into the pelagic plateau known as Julian High[26], which coincided with the opening of the Alpine Tethys[17, 18]. In recent years, extensive studies of Late Triassic and Jurassic basinal succession were performed on Mt Kobla[33 and references therein]. These studies incorporated the elaboration of a detailed geological map, during which the herein-described ammonite site was discovered.
Structural setting
Structurally, the area belongs to the Southern Alps, which are characterized by the south-directed Miocene thrusting (Figure 1).
JCP deposits compose the structurally higher Julian Nappe, whereas SB sediments are found in the structurally lower Tolmin Nappe[34]. In the Mt Kobla area, the contact between the JCP and SB successions is exceptionally not a thrust-fault but a steep, northward-deeping fault which eastward separates into two divergent faults (Figure 2). JCP successions are in a sub-vertical to slightly inverse position with steep deeping towards the north, whereas SB successions are repeated several times due to lower-order nappe stacking and deeping normally to the north. Between the JCP and SB successions the small Krevl tectonic block is emplaced[35]. It shows Lower Jurassic JCP- and Middle to Upper Jurassic SB-characteristics. Parallel and north to the main fault runs another fault that separates Triassic and Jurassic JCP successions. A few other faults with minor displacement were recognized in the mapped area (Figure 2a).
EXTERNAL DINAR1DES
Trnovo Nappe Hrušica Nappe
SOUTHERN ALPS ^ Julian Nappe
Tolmin Nappe

Oligocene to recent
deposits
fault
Southalpine front
overthrust boundary in the Southern Alps region
detachment plane position of investigated area
Figure 1: The location of Mt Kobla and the macrotectonic subdivision of western Slovenia; simplified after[34].
Figure 2: a) Geological map of the Mt Kobla area, b) orthophoto of the topmost part of the Kobla skiing ground (public data of the Republic of Slovenia, Geodetic Survey RS, DOF 05,2011) with the location of the ammonite site (marked with a star).
General description of the Julian Carbonate Platform succession on Mt Kobla
The oldest JCP formation of the mapped area is the Norian-Rhaetian Dachstein reef limestone (Figure 3). The coral Dictichophyllia norica and sponge Cheilosporites tirolensis were reported on Mt Kobla[36, 37]. The contact with Jurassic deposits is at the previously mentioned fault. It outcrops well on the Kobla skiing-ground where the inner fault zone is up to 0.5 meter wide, partly eroded and surrounded by tectonic mirrors. Kossmat[29] recognized this fault in the railway tunnel and reports clastics from the inner fault zone. Budkovič[38] described a thick marl-bed 2 m between the Triassic and Jurassic JCP successions in the Bohinj area. Taking into concern this data and the fact that the fault plane is parallel to the bedding of the overlying Jurassic strata, this fault could have formed due to the tectonic activation of a marl-dominated formational boundary.
Traditionally, the Triassic/Jurassic boundary on the JCP is placed at the disappearance of stromatolites and the occurrence of ooidal lime-stone[15]. The overall Jurassic succession in the studied area is 250 m thick. The lower 170 m are characterized by peloidal/ooidal limestone. In the upper 60 m of this interval on the Kobla skiing-ground, where the outcrops are good, they show clear bedding with a bed thickness from 10 cm up to several meters. Cross-lami -nation occurs in these beds. The package of bioclastic limestone occurs as early as this part of the succession, but is overlain again by pe-loidal/ooidal limestone. The following 80 m are dominated by bioclastic limestone and will be described in greater detail in the next chapter. The limestone succession is overlain by a 0.5-meter-thick marl, which presumably correlates with the marl-dominated Toarcian formations known from the surrounding basins[39-42]. The entire succession ends with Biancone-type limestone, i.e., thin-bedded mudstone/wackestone with chert nodules. This facies is characteristic for latest Jurassic and early Cretaceous successions of basins and drowned platforms of the entire Adriatic passive margin[17, 22, 41 43-45].
Figure 3: Schematic stratigraphic column of the Julian Carbonate Platform succession of Mt Kobla.
Facies of the Ammonite-bearing beds
The entire succession with ammonites is 80 m thick (Figure 4d, e). It is characterized by gray and, in the upper part, also reddish-gray bio-clastic limestone. It is wackestone composed of abundant crinoids and sponge spicules, and rarer filaments, ostracods, benthic foramin-ifera, juvenile ammonites, brachiopods and calcareous sponges (Figure 4b, g). In the lower part, stromataxis structures and sponges in a primary growth-position were observed (Figure 4c).
Bioclastic limestone alternates with laminas and thin beds of crinoidal limestone which is grainstone or packstone composed predominantly of crinoids, and rarer intraclasts and shells (Figure 4b, h). It becomes dominant in the middle part of this interval, where it composes a several-meter-thick package of occasionally graded beds.
The topmost part of the entire interval is characterized again by alternating bioclastic and crinoidal limestones. It additionally contains neptunian dykes (Figure 4h) composed of reddish marly limestone with crinoids as predominant grains, but lithoclasts of surrounding rocks were also detected. They usually fill cavities which are oriented perpendicularly as well as parallel to the bedding. A few-meters-thick limestone breccia bed is interstratified in the upper part of the interval. In the lower part it shows chaotic internal organization (slump) which becomes clearly brecciated towards the top of the bed. Clasts correspond to surrounding bioclastic limestone, but lithoclasts of peloi-dal/ooidal limestone also occur. The ammonites presented in this paper were found just below this bed.
Ammonites and biostratigraphy
Ammonites were found on the top of the Kobla skiing-ground, close to the uppermost exiting stations of the chair-pull (Figure 2b) and taken from a bedding plane exposed on the rock crevice that occurs at the crossing of two skiing trails (E13°57'29" N46°14'21"). After the exploration of the outcrop, the bedding plane was
systematically opened by an additional square meter (Figure 4d, e). The best-preserved specimens were taken to the laboratory together with host-rock, where they were cleaned and photographed. A few selected examples were treated with a pneumatic tool for additional mechanical preparation, but this revealed to be too destructive because of the strong lithi-fication and implementation of fossils in the host-rock (Figure 5h). From the collected material two specimens were determined on the generic level as Canavaria sp. (Figure 5a) and Neolioceratoides sp. (Figure 5b, c). Although they exhibit poor preservation for qualitative paleontological analysis, they provide precious biostratigraphic dating, because this association is typical of Upper Pliensbachian, more precisely upper Domerian (spinatum AZ). Other collected material was too poorly preserved for determination; however it is represented in Figure 5 (d-i). Ammonite data is further constrained by benthic foraminifer Agerina mar-tana Farinacci (Figure 4g), which is common in bioclastic limestone. Although it is generally considered as Lower Jurassic, Chiochini et al.[46] narrowed its appearance to the Pliensbachian. Considering these facts, the bioclastic/crinoi-dal limestone of Mt Kobla is Pliensbachian and the topmost part with limestone breccia and neptunian dykes is (?upper) Domerian in age.
Pliensbachian tectono-sedimentary event based on new ammonite dating
The Late Triassic and Early Jurassic succession of the JCP outcropping on the northern part of Mt Kobla is characterized by a highly productive, shallow-water, high-energy sedimentary environment of barrier reef and ooidal shoal, respectively. In the Pliensbachian, a distinct facies change from peloidal/ooidal to bioclas-tic limestone records the deepening of the sedimentary environment. Namely, bioclastic limestone indicates the sedimentation on the outer platform to the upper slope. Interstratified crinoidal limestone points to high-energy depositional conditions. The thin laminas of the crinoidal limestone were most probably deposited by bottom currents, whereas thicker
beds could have originated due to high-energy resedimentation events such as tempestites or turbidites. The deepening of the sedimentary environment could have been initially linked to eustatic oscillations of the relative sea-level because in the Tethyan Realm, Pliensbachian is characterized by a second-order transgres-
sive/regressive cycle, (T5/R5 in[47]), whereas the sedimentation documented in the topmost part of the succession was firmly governed by accelerated tectonic subsidence. This prominent Pliensbachian tectonic event is regionally evidenced by the disintegration of the JCP and differential subsidence of separated
Figure 4: a) fault between Dachstein Reef Limestone (left) and peloidal/ooidal limestone (right), b) bioclastic limestone with laminas of crinoidal limestone (arrows), c) sponge (1.7 cm in diameter) in the growth-position within bioclastic limestone, d) excavation on the ammonite site with visible ammonite bed-plane (arrow), e) ammonites on the bedding plane, f) juvenile ammonites in wackestone, g) spiculitic wackestone overlain with erosional contact by crinoidal grainstone; in the upper right corner is enlarged foraminifer Agerina martana Farinacci - 0.2 mm in length, h) wackestone with ammonite and contact with neptunian dyke (left) filled predominantly with crinoids.
Figure 5: Ammonites: a) Canavaria sp., b) Neolioceratoides sp. - not to scale; enlarged Figure 5c, c) Neolioceratoides sp., d-i) undetermined specimens (Figures f, g, h, and i also show casts; Figures e and h show a lateral view).
blocks117, 18, 40]. In the adjacent SB, it is recorded by the highly-variable thickness of the Toarcian Perbla Formation141, 42]. Neptunian dykes characterize the JCP margin[26, 48, 49] and the earliest activation phases are dated as Pliensbachian[50]. In the Bohinj area, Ribnica breccia, which is a debrite composed of limestone and rare chert clasts, covers the basinal Zatrnik Formation and is dated as Lower Jurassic and related to a Pliensbachian tectonic activity[45, 51]. At Mt Kobla, the tectonic event is in accordance with previously-described sedimentary indicators. Namely, it is well-manifested at the top of the carbonate succession with the occurrence of neptunian dykes and limestone breccia. It is this part, from which ammonites were retrieved and dated the main Pliensbachian tectonic intensification to the (?upper) Domerian.
Correlation with other successions of the Julian Carbonate Platform
Ammonite-bearing beds from Mt Kobla are characterized by bioclastic limestone that is the time and facies equivalent of dominant beds in the Sedlo Formation from the Bovec Trough[17, 40]. This trough originated after the Pliensbachian disintegration of the JCP and the Sedlo Formation indicates the initial deepening phases. It is overlain by a Fe-Mn nodular crust which points to unconformity[17]. No such crust was detected on Mt Kobla - however the overlying marls correlate with clay-rich Skrile Formation from the Bovec Trough, which was dated with radiolarians to the Toarcian[39]. The age of the formation was further constrained by chemostratigraphic recognition of the Toarcian OAE[52].
The Mt Kobla JCP succession correlates also with developments from the Bohinj area, where Buser (1986) described Lower Jurassic crinoidal limestone in which Härtel[11] found rich brachiopod, bivalve and ammonite fauna in several locations, mostly active quarries near Bohinjske Češnjice in Bitnje villages. Due to a similar setting and close correlation, a non-revised list of cephalopods is presented herein. Härtel[11] recognized Phylloceras gey-eri Bonarelli, P. anonymum Hass, P. frondosum Reynès spv Rhacophyllites ex aff. liberti Gemm.,
R. planispira Reynès, R. (Meneghiniceras) lar-iensis Meneghini, Lytoceras cf. secernendum de Stefani, L. nothum? Meneghini., Amaltheus mar-garitatus Montfort, Harpoceras (Arieticeras) retrosicosta Oppel, H. bertrandi Kilian, H. geyeri Del Campana, H. cf. reynèsi Fucini, H. (Grammoc-eras) uequiondulatum Bettoni, H. percostatum Fucini, H. (Harpoceratoides) serotinum Bettoni, and Atractites ex. aff. A. indunensis Stop. These quarries had already been abandoned and were mostly inaccessible during the geological mapping in eighties[15], which today results in practically unrecognizable sites[53]. Buser[15] outlined that crinoidal limestone laterally and vertically passes to ooidal limestone and in the upper part contains interbeds of micritic (?bioclastic) limestone and, additionally to Mt Kobla, nodular chert. Prominent facies changes of the Jurassic rocks in the Bohinj Valley were also described by Cousin[30], who recognized two distinct facies: a more shallow-water facies to the south and the deeper-water Zatrnik Formation to the north. For the latter, Kukoč et al.[45] proposed on the basis of overlying Cretaceous strata an outermost, ocean-ward paleo-geographic location within present-day Slovenia, which is comparable to the developments of the Inner Dinarides. However, exact spatial stratigraphic as well as structural relationships within Jurassic strata in this area remain vastly unresolved[51]. On the contrary, the Mt Kobla succession exhibits a clear upwards deepening trend with well-dated and well-expressed tectonic phase which consolidates its importance in the understanding of the region's Jurassic sedimentary evolution and urges further research.
Conclusions
Jurassic ammonites in the area of present-day Slovenia are only sporadically preserved and just three locations have so-far been studied in detail, which amplifies the importance of newly-discovered sites. At Mt Kobla the overall Jurassic succession begins with peloidal/ooidal limestone. Upwards, it passes into bioclastic and crinoidal limestones which indicate the deepening of the sedimentary environment. At the top of the entire JCP succession limestone
breccia and neptunian dykes additionally occur and point to a regionally-recognized tectonic event. Within these strata ammonites of genera Canavaria and Neolioceratoides were determined which date to the Upper Pliensbachian (?upper Domerian). The succession correlates with successions which sedimented in environments located on the JCP margins and drowned to basinal depth during the Jurassic. Similarly, on Mt Kobla the platform carbonates are overlain by ?Toarcian marl and latest Jurassic Bian-cone-type limestone which was deposited after JCP drowning.
Acknowledgments
This paper was written to tribute the jubilee of Professor Jernej Pavšič, Ph.D. mentor of the first author. It was always and still is a pleasure to work with him. I hope (for him and also me) that in the future I and my co-workers will write several such jubilee-type manuscripts. Especially, I would like to acknowledge his skillful help, which facilitated and accelerated elaboration of the dissertation' final version and defense. Geological mapping of Mt Kobla was assisted by Petra Žvab Rožič, Nina Rman, Nastja Rogan Šmuc, Mojca Kavčič, Damjan Ul-amec, Boštjan Bradaškja, Blaž Milanič, Petra Škrinjar and Erik Svetličič. Ammonites were retrieved in the field with help of Simon Smrkolj and Matej Ograjenšek. Research was sponsored by the Slovenian Research Agency in projects Z1-9759 and MR 636/2002.
References
[1]	Bambach, R. K. (2006): Phanerozoic Biodiversity Mass Extinctions. Annu. Rev. Earth Planet. Sci., 34, 127-55.
[2]	Kullmann, J., Ramovš, A. (1980): Cephalopoden aus dem Oberkarbon (Gzhelium) und Interperm der Karawanken. Geologica et Paleontologica, 14, 195-208, Marburg.
[3]	Buser S., Ramovš, A. (1968): Razvoj triadnih skladov v slovenskih Zunanjih Dinaridih. Prvi kolokvij o geologiji Dinaridov I. del, Ljubljana, 33-42.
[4]	Petek, T. (1997): Skitske in anizijske plasti v kamnolomu pri Hrastenicah in pomembne najdbe zgornjeanizijskih fosilov. Geologija, 40, 119-151.
[5]	Žlebnik, L. (1955): Triadni cephalopodi izpod Pece. Geologija, 3, 216-219.
[6]	Jurkovšek, B. (1978): Biostratigrafija karnijske stopnje v okolici Mežice. Geologija, 21, 2, 173-208.
[7]	Kolar - Jurkovšek, T. (1991): Mikrofavna srednjega in zgornjega triasa Slovenije in njen biostratigrafski pomen. Geologija, 33, 21-170.
[8]	Kolar-Jurkovšek, T., Jurkovšek, B. (2010): New paleontological evidence of the Carnian strata in the Mežica area (Karavanke Mts, Slovenia): Conodont data for the Carnian Pluvial Event. Palaeogeography, Palaeoclimatology, Palaeoecology, 290, 81-88.
[9]	Pavšič, J. (1995); Fosili, zanimive okamnine iz Slovenije. Ljubljana: Tehniška založba Slovenije; 139 pp.
[10]	Pavšič, J. (2009): Paleontologija; Paleobotanika in nevretenčarji. 2. dop. in pop. izd. Ljubljana; Na-ravoslovnotehniška fak., Odd. za geologijo; 460 pp.
[11]	Härtel, F. (1920): Stratigraphische und Tektonische Notizen über das Wocheiner - Juragebeit. Verh. Geol. R. A., 8-9, 134-153.
[12]	Mihajlovič, M., Ramovš, A. (1964): Liadna cefolo-podna favna na Begunjščici v Karavankah. Razprave IV. razr. SAZU, 8, 417-438.
[13]	Salopek, M. (1933): O gornjoj juri u Dolini sedmerih jezera. Jugoslavenska akademija znanosti i umjeto-nosti, 246, 110-118.
[14]	Ramovš, A. (1975): Amoniti v dolini Triglavskih jezer. Proteus, 37, 332-340.
[15]	Buser, S. (1986): Tolmač k Osnovni geološki karti SFRJ 1; 100 000 listov Tolmin in Videm (Udine). Zvezni geološki zavod, Beograd; 103 pp.
[16]	Gawlick, H. J., Missoni, S., Schlagintweit, F., Suzuki, H., Frisch, W., Krystyn, L., Blau, J., Lein, R. (2009): Jurassic Tectonostratigraphy of the Austroalpine Domain. Journal of Alpine Geology, 50, 1-152.
[17]	Šmuc, A. (2005): Jurassic and cretaceous stratigraphy and sedimentary evolution of the Julian Alps, NW Slovenia. Ljubljana; Založba ZRC, ZRC SAZU; 98 pp.
[18]	Šmuc, A., Rožič, B. (2010): The Jurassic Prehodavci Formation of the Julian Alps: easternmost outcrops of Rosso Ammonitico in the Southern Alps (NW Slovenia). Swiss journal of geosciences, 103, 2, 241-255.
[19]	Praprotnik, J., Kastelic, A., Gale, L., Šmuc, A., Rožič, B. (2013): Jurske plasti z manganovimi obogatitvami na Begunjščici. Geološki zbornik, 22, 127-130.
[20]	Di Stefano, P., Galacz, A., Mallarino, G., Mindszenty, A., Vörös, A. (2002): Birth and early evolution of a Jurassic escarpement: Monte Kumenta, Western Sicily. Facies, 46, 273-298.
[21]	Santantonio, M., Muraro, C. (2002): The Sabina Plateau, Palaeoescrapment, and Basin-Central Apennines. In: Santantonio, M. (Ed.), General field trip guidebook. VI international symposium on the Jurassic system, 12-22 September 2002, 271-315.
[22]	Martire, L., Clari, P., Lozar, F., Pavia, G. (2006): The Rosso Ammonitico Veronese (Middle-Upper Jurassic of the Trento Plateau): A proposal of lithostrati-graphic ordering and formalization. Rivista Italiana di Palentologia e Stratigrafia, 112, 2, 227-250.
[23]	Missoni S., Gawlick H. J. (2011): Jurassic mountain building and Mesozoic-Cenozoic geodynamic evolution of the Northern Calcareous Alps as proven in the Berchtesgaden Alps (Germany). Facies, 57, 137-186.
[24]	Donatelli, U., Tramontana, M. (2014): Platform-to-basin facies transition and tectono-sedimentary processes in the Jurassic deposits of the Furlo
area (Umbria-Marche Apennines, Italy). Facies, 60, 541-560.
[25]	Jurkovšek, B., Cvetko Tešović, B., Kolar-Jurkovšek, T. (2013): Geologija Krasa - Geology of Kras. Ljubljana; Geološki zavod Slovenije, 205 pp.
[26]	Buser, S. (1989): Development of the Dinaric and Julian carbonate platforms and the intermediate Slovenian basin (NW-Yugoslavia). In: Carulli, G. B., Cucchi, F., Radrizzani, C. P. (eds): Evolution of the Karstic carbonate platform: relation with other peri-adriatic carbonate platforms. Mem. Soc. Geol. Ital., 40 (1987), 313-320, Roma.
[27]	Goričan, Š., Košir, A., Rožič, B., Šmuc, A., Gale, L., Kukoč, D., Celarc, B., Črne, A. E., Kolar-Jurkovšek, T., Placer, L., Skaberne, D. (2012): Mesozoic deep-water basins of the eastern Southern Alps (NW Slovenia). In: 29th IAS Meeting of Sedimentology [10-13 September 2012, Schladming]: field trip guides, (Journal of Alpine geology, 54). Wien: GEOAUSTRIA, 2012, 54, 101-143.
[28]	Buser, S. (1987): Osnovna geološka karta SFRJ 1: 100 000, list Tolmin in Videm. Zvezni geološki zavod, Beograd.
[29]	Kossmat, F. (1907): Geologie des Wocheiner Tunnels und der Sudlichen Anschluslinie. Denkschriften d. mathem. - naturwis. K1, Bd. 83, Wien.
[30]	Cousin, M. (1981): Les repports Alpes - Dinarides. Les confins de I'talie et de la Yougoslavie. Sociètè
Gèologique du Nord, Publi., 5, 1, 521 pp.; 2 - Annexe, 521 pp.
[31]	Buser, S., Kolar-Jurkovšek, T., Jurkovšek, B. (2008): The Slovenian Basin during the Triassic in the Light of Conodont Data. Boll. Soc. Geol. It. (Ital. J. Geosci.), 127, 2, 257-263.
[32]	Vrabec, M., Šmuc, A., Pleničar, M., Buser, S. (2009): Geological Evolution of Slovenia - An Overview. In: Pleničar, M. Ogorelec, B., Novak, M. (eds). Geologija Slovenije - The Geology of Slovenia; Geološki zavod Slovenije, 23-40.
[33]	Rožič, B., Gale, L., Kolar - Jurkovšek, T. (2013): Extent of the Upper Norian - Rhaetian Slatnik Formation in the Tolmin Nappe, eastern Southern Alps. Geologija, 56, 2, 175-186.
[34]	Placer, L. (1999): Contribution to the macrotectonic subdivision of the border region between Southern Alps and External Dinarides. Geologija, 41, 223-255.
[35]	Rožič, B., Šmuc, A. (2009): Jurska evolucija prehodne cone med Julijsko karbonatno platformo in Slovenskim bazenom. Geološki zbornik, 20, 146-151.
[36]	Turnšek, D., Buser, S. (1991): Norian-Rhetian Coral Reef Buildups in Bohinj and Rdeči rob in Southern Julian Alps (Slovenia). Razprave IV razreda SAZU, 32, 215-257.
[37]	Turnšek, D. (1997): Mezosoic Corals of Slovenia. Založba ZRC, Ljubljana, 512 pp.
[38]	Budkovič, T. (1978): Stratigrafija Bohinjske doline - The stratigraphic sequence of the Bohinj Valley. Geologija, 21, 239-244.
[39]	Goričan, Š., Šmuc, A., Baumgartner, P. (2003): Toar-cian Radiolaria from Mt. Mangart (Slovenian-Italian border) and their paleoecological implications. Marine Micropaleontology, 49, 275-301.
[40]	Šmuc, A., Goričan, Š. (2005): Jurassic sedimentary evolution of a carbonate platform into a deep-water basin, Mt. Mangart (Slovenian-Italian border). Riv. Ital. Paleont. Stratigr., 111, 1, 45-70.
[41]	Rožič, B. (2009): Perbla and Tolmin formations: revised Toarcian to Tithonian stratigraphy of the Tolmin Basin (NW Slovenia) and regional correlations. Bull. Soc. géol. Fr., 180, 5, 411-430.
[42]	Rožič, B., Šmuc, A. (2011): Gravity-flow deposits in the Toarcian Perbla formation (Slovenian basin, NW Slovenia). Riv. Ital. Paleontol. Stratigr., 117, 2, 283-294.
[43]	Goričan, Š. (1994): Jurassic and Cretaceous radiolar-ian biostratigraphy and sedimentary evolution of the Budva Zone (Dinarides, Montenegro). Mémoires de Géologie, 18, Lausanne, 177 pp.
[44]	Clari, P., Masetti, D. (2002): The Trento Ridge and the Belluno Basin. In: Santantonio M. (ed.): General Field Trip Guidebook, VI International Symposium on the Jurassic System, 12-22 September 2002, 271-315, Palermo.
[45]	Kukoč, D., Goričan, Š., Košir, A. (2012): Lower Cretaceous carbonate gravity-flow deposits from the Bohinj area (NW Slovenia): evidence of a lost carbonate platform in the Internal Dinarides. Bull. Soc. géol. Fr., 183, 4, 383-392.
[46]	Chiocchini, M., Farinacci, A., Mancinelli, A., Molinari, V., Potetti, M. (1994): Biostratigrafia a foraminiferi, dasicladali e calpionelle delle successioni carbon-atiche mesozoiche dell'Appennino centrale (Italia). Studii geologici Camerti, Spec. Pubi., 9-129.
[47]	Graciansky, P., Jacquin, T., Hesselbo, S.P. (1998): The Ligurnian cycle: an overview of Lower Jurassic 2nd-order transgressive/regressive facies cycles in Western Europe. In: Graciansky, P., Hardenbol, J., Jacquin, T. & Vail, P.R. (eds.). Mesozoic and Cenozoic Sequence stratigraphy of European Basins, SEMP Special Publications, 6, 467-479.
[48]	Babić, L. (1981): The origin of "Krn breccia" and the role of the Krn area in the Upper Triassic and Jurassic history of the Julian Alps. Vesnik Zavoda geol geofiz istraživanja NR Srbije, 38/39, 59-87.
[49]	Jurkovšek, B., Šribar, L., Ogorelec, B., Jurkovšek-Kolar, T. (1990): Pelagic Jurassic and Cretaceous beds in the western part of the Julian Alps. Geologija, 31/32, 285-328.
[50]	Črne, A. E., Šmuc, A., Skaberne, D. (2007): Jurassic neptunian dikes at Mt Mangart (Julian Alps, NW Slovenia). Facies, 53, 2, 249-265.
[51]	Kukoč, D. (2014): Jurassic and Cretaceous radiolarian biostratigraphy of the Bled Basin (northwestern Slovenia) and stratigraphic correlations across the Internal Dinarides. Unpublished PhD Thesis, University of Ljubljana, (submitted).
[52]	Sabatino, N., Neri, R., Bellanca, A., Jenkyns, H. C., Masetti, D., Scopelliti, G. (2011): Petrography and high-resolution geochemical records of Lower Jurassic manganese rich deposits from Monte Mangart, Julian Alps. Palaeogeogr. Palaeoclimatol. Palaeoecol., 299, 97-109.
[53]	Anko, K. P. (2014): Some Early Jurassic brachiopod faunas from Slovenia. RMZ - Material and Geoenvi-ronment, this volume.