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Arkadev V.V., Bogdanova T.N., Lobacheva S.V., Kalacheva E.D., Sey I.I. (2008) Berriasian Stage of the Crimean Mountains: Zonal Subdivisions and Correlation // Stratigraphy and Geological Correlation. Vol. 16, No. 4, pp. 400422.

Biostratigraphy of the Berriasian Stage in the Crimean Mountains is specified and substantiated. Fragments of all the standard stage zones (jacobi, occitanica, and boissieri) are distinguished based on the found index species, and position of the JurassicCretaceous boundary is targeted. According to verified distribution of ammonites, the jacobi Zone is divided into the jacobi and grandis subzones crowned by the Malbosiceras chaperi Beds. The Tirnovella occitanicaRetowskiceras retowskyi Beds and overlying Dalmasiceras tauricum Subzone are recognized in deposits of the occitanica Zone. The upward succession of biostratigraphic units established in the boissieri Zone includes the EuthymicerasNeocosmoceras Beds, Riasanites crassicostatus Subzone, Symphythyris arguinensis and jabronella sf. paquieriBerriasella callisto Beds. The last biostratigraphic unit is suggested in this work instead the former Zeillerina baksanensis Beds. Except for the jacobi Zone, the substantiated ammonoid zonation is practically identical to the Berriasian biostratigraphic scale of the northern Caucasus, although the BerriasianValanginian boundary has not been defined in the Crimean Mountains based on ammonites. Several marker levels of bivalve mollusks and four biostratigraphic subdivisions of brachiopod scale are distinguishable here. As for the latter, these are (from the base upward) the Tonasirhynchia janini, Belbekella airgulensisSellithyris uniplicata, Symphythyris arguinensis, and Zeillerina baksanensis beds.



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