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Biostratigraphy and magnetostratigraphy of the uppermost Tithonian–Lower Berriasian in the Theodosia area of Crimea (southern Ukraine)

Bakhmutov V. G., Halásová E., Ivanova D. K., Józsa Š., Reháková D., Wimbledon W. A. P.

Geological Quarterly

2018

Vol. 62, No. 2

197--236

We present evidence for the uppermost Jurassic-lowest Cretaceous interval in Crimea, coastal southern Ukraine. Three facies zones are distinguished in the upper Dvuyakornaya and the Mayak formations of the eastern Crimean Peninsula: basinal, slope and toe-of-slope zones. In this interval we identify the lowest Berriasian Jacobi and Grandis subzones of authors, in expanded form, exceeding 160 metres in thickness. We present new magnetostratigraphic interpretations, and identify two normal and two reversed polarity intervals, assigned to M19n, M18r, M18n and M17r, with M19n2n, M19n1r and M19n1n identified in the uppermost Dvuyakornaya Formation. In the Mayak Formation we record the top of M19n.1n, with M18r, M18n and a thick M17r above. In these two formations component calpionellid species have been identified which characterise the Alpina, Ferasini and Elliptica subzones (Calpionella Zone). In M19n, the FADs of the calcareous nannofossils Hexalithus strictus, Cruciellipsis cuvillieri, Nannoconus wintereri, N. steinmannii minor and N. kamptneri minor are found, which is consistent with other Tethyan regions. N. steinmannii steinmannii and N. kamptneri kamptneri first appear in M18r at Ili Burnu . Specimens of the apparently Tithonian foraminiferan index Anchispirocyclina lusitanica are found, but in the Berriasian lower Mayak Formation.

Early?–Middle Jurassic dinoflagellate cysts and foraminifera from the dark shale of the Pieniny Klippen Belt between Jarabina and Litmanová (Slovakia) : age and palaeoenvironment

Gedl P., Józsa Š.

Annales Societatis Geologorum Poloniae

2015

Vol. 85, No. 1

91--122

The results presented are a part of the biostratigraphical and palaeoenvironmental studies of the authors on the microfauna and organic-walled dinoflagellate cysts from the Mesozoic dark deposits of the Pieniny Klippen Belt. The authors present the latest results from the Lower–Middle Jurassic strata, including the Szlachtowa and the Skrzypny Shale formations in the Slovak part of the Pieniny Klippen Belt near the villages of Jarabina, Kamienka and Litmanová. Material for the present study comes from exposures along the Malý Lipník, Veľký Lipník and Riečka Streams, and from the Jar-1 borehole, near Jarabina. The authors document the microfaunal and phytoplanctonic content of these rocks that contain over 50 foraminifera and 20 dinoflagellate cyst species. Their Middle Toarcian?–Aalenian to Bajocian–Bathonian ages are proposed and discussed. Quantitative and qualitative variations of both microfossil groups are interpreted as reflecting various sedimentary settings, related mainly to the variable intensity of influx of terrestrial matter into marine basins, leading to different bottom-water living conditions.