| mhorn | Дата: Friday, 12.12.2014, 16:13 | Сообщение # 1 |
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| Rožič B., Venturi V., Šmuc A. (2014) Ammonites from Mt Kobla (Julian Alps, NW Slovenia) and their significance for precise dating of Pliensbachian tectono-sedimentary event // RMZ – M&G. Vol.61. P.191–201.
http://www.rmz-mg.com/letniki/rmz61/RMZ61_0191-0201.pdf
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 Late 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.
Middle Jurassic - Lower Cretaceous ammonites & aptychi
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