Middle Aptian Orbitolinid limestones in Belgrade (Serbia): microfacies and depositional environment

Lower Cretaceous (Aptian) shallow-marine limestones with intercalated polymictic conglomerates were investigated with respect to their biostratigraphic age and their microfacies. They are the younger part of the generally carbonate-siliciclastic Lower Cretaceous deep-water (max. few hundred metres) turbiditic sequences (“Paraflysch”) of the so-called East Vardar zone in the Belgrade area. The biostratigraphic age of the limestones was determined by orbitolinid foraminifera: the co-occurrence of Dictyoconus? pachymarginalis SCHROEDER and Mesorbitolina texana (ROEMER) besides various other microfossils suggest a biostratigraphic age of this shallow- marine limestone succession as middle Aptian (Gargasian). Radiolarite components in the conglomerates are Triassic in age and were derived from the obducted Middle Triassic to Middle Jurassic Neo-Tethys ophiolites and/or their ophiolitic mélanges on the wider Adria plate. From both the first precise biostratigraphic age dating as middle Aptian combined with microfacies analysis of these shallow-marine limestones and the component spectrum in the intercalated conglomerates, it can be concluded that the Lower Cretaceous turbiditic “Paraflysch” succession was deposited on the eastern rim of the Dinarides. The results will allow a better comparison of the different Lower Cretaceous sedimentary successions deposited on the eastern margin of the Dinarides

The Jurassic of the Northern Calcareous Alps and its Global Boundary Stratotype Section and Point (GSSP)

This paper summarises the recent progress and current status of research undertaken on the Jurassic strata of the Northern Calcareous Alps. The Jurassic GSSP (Global Boundary Stratotype Section and Point) at the Kuhjoch section of the Northern Calcareous Alps is also explained in detail. The base of the Jurassic strata is defined at this location by the occurrence of the oldest known Jurassic ammonite, Psiloceras spelae tirolicum Hillebrandt & Krystyn. The Upper Triassic to Lower Jurassic successions of the Northern Calcareous Alps were developed along the passive continental margin of the Neotethys Ocean. In Middle Jurassic time, a change in the plate tectonic setting influenced the sedimentary facies, which suggest northwest-verging nappe stacking in association with the partial closure of the Neotethys Ocean. Deep-water radiolarite basins developed in the area in front of the advancing nappes and were the sites of mass flow deposits that produced olistoliths of various sizes. These olistoliths were included in the radiolarite matrices. Therefore, the use of radiolarian fossils as a dating method plays an important role in understanding the formations of the Northern Calcareous Alps.ジュラ系の国際境界模式層序・位置がオーストリア国チロル州のクーヨッホ層序断面に置かれることが2010年に正式に決まった．それはジュラ紀最古のアンモナイトPsiloceras spelae tirolicumが初産出する層準で，ケンドゥルバッハ層の基底から5.8m上位に位置する．筆者らは2012年に行われた国際堆積学会の巡検でクーヨッホ層序断面を訪れたので，その概要を紹介する． ジュラ系の国際模式境界が置かれた北部石灰アルプスでは，近年の研究でオリストリスの基質をなす珪質堆積岩からジュラ紀の放散虫化石が数多く報告され，年代決定に有効なことが示された．本稿では特に研究が進んでいるザルツカンマーグート地方の代表的なジュラ紀層を紹介し，北部石灰アルプスの地質構造発達史を概観する

The Economy of Dürrnberg-Bei-Hallein: An Iron Age Salt-mining Centre in the Austrian Alps

For the first time in English, we present a summary of the international programme of excavation work carried out between 1990 and 2001 in and around the Iron Age salt-mining complex of the Diirrnberg region, south of Salzburg. First we describe the results of excavation in the prehistoric adits, and of work to locate and survey associated settlements. This is followed by a series of specialist reports embracing floral and faunal remains, palaeodiet and parasitology, leather and woodworking and other crafts. The evidence suggests that a complex inter-relationship existed between the Diirrnberg and other communities in the Alpine foreland. It is assumed that the Diirrnberg was under the control of an elite - perhaps a local dynasty whose wealth is reflected in the grave

Mesozoic tectonostratigraphy of the Western Tethys Realm – a review

The Mesozoic sedimentary sequences in the Western Tethys Realm are incorporated in different mountain ranges, most of them located in the eastern Mediterranean area (Eastern and Southern Alps; Western, Eastern and Southern Carpathians; Dinarides, Albanides, Hellenides; units in the Pannonian realm: Pelso, Tisza), others are located to the west (e.g. the Apennine and the Betic Cordillera) These mountain ranges were formed since the Jurassic and experienced in parts polyphase mountain building processes and deformation, lasting until today. Therefore, the tectonostratigraphic evolution of the different Wilson cycles are in cases hard to assign to a specific cycle, because the evolution of the different Wilson cycles is overlapping. This resulted in contrasting palaeogeographic reconstructions and controversial regional tectonic interpretations. In general, two different Wilson cycles can be distinguished. The older Wilson cycle reflect the geodynamic history of the Neo-Tethys (Meliata-Hallstatt, Maliac, Vardar, Pindos/Mirdita/Dinaridic oceans in other nomenclature), and the formed orogen is part of the Tethysides with following evolution as documented in the sedimentary record of the wider Adria plate: – A Late Permian to Middle Anisian rift (graben) stadium with sedimentation of siliciclastics and carbonate ramp deposits in an epicontinental sea. – A Middle Anisian to Middle Jurassic passive margin evolution after the late Middle Anisian oceanic break-up: a) The complex Middle to Late Triassic shallow- to deep-water carbonate platform evolution from the inner shelf (platform facies) to the outer shelf (open-marine basinal facies), and b) the Early to Middle Jurassic pelagic platform evolution. – A Middle to Late Jurassic convergent tectonic regime triggered by ophiolite obduction (“active continental margin evolution”) with the interplay of thrusting, trench and trench-like basin formation, mass movements, and the onset and growth of carbonate platforms, followed by latest Jurassic to Early Cretaceous mountain uplift and unroofing. – Final closure of the remaining open part of the NeoTethys (= Vardar Ocean) in Late Cretaceous to Paleogene times. The younger Wilson cycle reflect the geodynamic history of the Alpine Atlantic (Ligurian, Piemont, Pennine, Vah, Alpine Tethys oceans in other nomenclature), and the formed orogen is part of the Alpides with following evolution as documented in the sedimentary record of the wider Adria plate: – An Early Jurassic (Hettangian to Toarcian) rift (graben) stadium with sedimentation of fully marine deposits in areas the rift cross-cut the older proximal Neo-Tethys shelf and siliciclastics and carbonate ramp deposits in areas the rift cross-cut continental domains. – A Middle Jurassic to Late Cretaceous passive margin evolution after the oceanic break-up since the Toarcian with formation of shallow-water platforms in latest Jurassic–earliest Cretaceous times in certain areas, but predominantly with deposition of hemipelagic sedimentary sequences. – ALate Cretaceous to Paleogene convergent tectonic regime triggered by subduction and subsequent continent (wider Adria)  – continent collision (Europe), followed by Neogene mountain uplift and unroofing. In contrast to the fairly well understood Alpine Atlantic Wilson cycle a lot of open questions exist regarding the NeoTethys Wilson cycle. The main focus is therefore the time frame before the “Mid-Cretaceous” mountain building process with the rearrangement of tectonic units, i.e. the Mesozoic plate configuration in the Western Tethys Realm. Due to the fact that the “Mid-Cretaceous” and younger polyphase tectonic motions and block rotations draws a veil over the older Mesozoic plate configuration, several crucial and still topical questions remain, e.g.: 1) How many Triassic-Jurassic oceans existed in the Western Tethyan Realm. Show these oceanic domains different life cycles, i.e. is the opening and the closure of these oceanic domains contemporaneous or differ their age, and where are the suture zones? In general, two main types of contrasting interpretations/models remain: a) Multi-ocean reconstructions with several oceanic domains between continental blocks, and b) One-ocean reconstruction: an allochthonous model which interprets the ophiolites as overthrust ophiolitic nappe stack (or single ophiolite sheet) from the Neo-Tethys to the southeast to east. 2) Were the Southern Alps/Dinarides/Albanides/Hellenides, the Eastern Alps/Western Carpathians plus some Pannonian units (ALCAPA), some units in the Circum-Pannonian realm (e.g., Tisza Unit), and Pelagonia (including Drina-Ivanjica Unit) independent microplates between independent oceanic domains in Triassic-Jurassic times? Or have these units been scattered by polyphase younger tectonic movements modifying an united continental realm (north-western part of Pangaea) of the Triassic European shelf? The Early Jurassic Pangaea break-up resulted, e.g., in the opening of the Central Atlantic Ocean and its eastward continuation, the Alpine Atlantic

SARSTEINIA BABAI N. GEN., N. SP., A NEW PROBLEMATIC SPONGE (INOZOA?) FROM THE LATE JURASSIC OF THE NORTHERN CALCAREOUS ALPS, AUSTRIA

The new problematic sponge Sarsteinia babai n. gen., n. sp. is described from the Kimmeridgian to Tithonian Plassen and Lärchberg Formations of the Northern Calcareous Alps of Austria. The type-locality is the Sarsteinalm north of Mount Hoher Sarstein in the Austrian Salzkammergut, other findings come from Mount Sandling, Mount Jainzen, Mount Trisselwand and the Litzlkogel-Gerhardstein-complex west of Lofer. Most findings can be attributed to a fore-reef to upper slope facies or slope-of-toe breccias, small fragments can occasionally also be found in the back-reef facies. The suprageneric systematic position of the new sponge is unknown so far since it shows morphological characteristics known from Inozoa but also from "stromatoporoids"

Emendation of the Grivska formation in its type area (Dinaridic Ophiolite Belt, SW Serbia)

Age, microfacies and depositional realm of the Grivska Formation is controversially discussed due to the fact that detailed investigations are missing. Based on reinvestigations of the type locality of the Grivska Formation and in adjacent areas, the following results can be drawn: 1) The Grivska Formation is of Late Triassic (Early Carnian to Rhaetian) age according to conodont dating. 2) Sedimentological and microfacies studies evidenced that the Grivska Formation was deposited on the continental slope and transitional to the Neo-Tethys Ocean. Based on the results of these investigations in the type area and several reference sections in the Dinaridic Ophiolite Belt, the Grivska Formation is emended and clearly defined. In the Dinaridic Ophiolite Belt, the Grivska Formation occurs only as clasts and blocks in the ophiolitic melange. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. ON-176015

Suprasubduction ophiolite (SSZ) components in a middle to lower upper Jurassic Hallstatt Mélange in the Northern Calcareous Alps (Raucherschober/Schafkogel area)

The Northern Calcareous Alps in the Western Tethys realm were affected in Middle to Late Jurassic times by a mountain building process triggered by ophiolite obduction similar to that in the Inner Western Carpathians or Inner Dinarides. In contrast to these other mountain ranges, in the Northern Calcareous Alps the obducted ophiolites or ophiolite derived components in the Bathonian-Oxfordian mélanges are missing. Cr-spinels in Kimmeridgian basinal deposits are the oldest known relics of a Jurassic ophiolite obduction. This study reveals new data from a newly detected Hallstatt Mélange below the Late Jurassic Plassen Platform in the southeastern Northern Calcareous Alps (Raucherschober/Schafkogel area). Upper Triassic Hallstatt Limestone blocks from the former distal northwestern continental margin of the Neo-Tethys Ocean, as well as ophiolite and radiolarite blocks from the Neo-Tethys Ocean floor rest within an upper Middle to lower Upper Jurassic radiolaritic-argillaceous matrix. Ophiolitic blocks show calc-alkaline volcanic arc affinity, defining the rocks as the product of intra-oceanic subduction and the formation of an early arc during stacking of the oceanic crust. Resedimented ribbon radiolarite blocks deposited above the newly formed suprasubduction (SSZ) ophiolites in the Neo-Tethys Ocean east of the island arc have a Middle Jurassic age. Later, at a time of decreasing tectonic activity, the Hallstatt Mélange was sealed by the Kimmeridgian-Tithonian Plassen Carbonate Platform, showing a shallowing-upward trend

Ophiolitic detritus in Kimmeridgian resedimented limestones and its provenance from an eroded obducted ophiolitic nappe stack south of the Northern Calcareous Alps (Austria)

The causes for the Middle to Late Jurassic tectonic processes in the Northern Calcareous Alps are still controversially discussed. There are several contrasting models for these processes, formerly designated “Jurassic gravitational tectonics”. Whereas in the Dinarides or the Western Carpathians Jurassic ophiolite obduction and a Jurassic mountain building process with nappe thrusting is widely accepted, equivalent processes are still questioned for the Eastern Alps. For the Northern Calcareous Alps, an Early Cretaceous nappe thrusting process is widely favoured instead of a Jurassic one, obviously all other Jurassic features are nearly identical in the Northern Calcareous Alps, the Western Carpathians and the Dinarides. In contrast, the Jurassic basin evolutionary processes, as best documented in the Northern Calcareous Alps, were in recent times adopted to explain the Jurassic tectonic processes in the Carpathians and Dinarides. Whereas in the Western Carpathians Neotethys oceanic material is incorporated in the mélanges and in the Dinarides huge ophiolite nappes are preserved above the Jurassic basin fills and mélanges, Jurassic ophiolites or ophiolitic remains are not clearly documented in the Northern Calcareous Alps. Here we present chrome spinel analyses of ophiolitic detritic material from Kimmeridgian allodapic limestones in the central Northern Calcareous Alps. The Kimmeridgian age is proven by the occurrence of the benthic foraminifera Protopeneroplis striata and Labyrinthina mirabilis, the dasycladalean algae Salpingoporella pygmea, and the alga incertae sedis Pseudolithocodium carpathicum. From the geochemical composition the analysed spinels are pleonastes and show a dominance of Al-chromites (Fe3+–Cr3+–Al3+ diagram). In the Mg/(Mg+ Fe2+) vs. Cr/(Cr+ Al) diagram they can be classified as type II ophiolites and in the TiO2 vs. Al2O3 diagram they plot into the SSZ peridotite field. All together this points to a harzburgite provenance of the analysed spinels as known from the Jurassic suprasubduction ophiolites well preserved in the Dinarides/Albanides. These data clearly indicate Late Jurassic erosion of obducted ophiolites before their final sealing by the Late Jurassic–earliest Cretaceous carbonate platform pattern