The Open Geology Journal

2012, 6 : 25-31
Published online 2012 June 28. DOI: 10.2174/1874262901206010025
Publisher ID: TOGEOJ-6-25

Some Calcareous Nannofossils from the Upper Jurassic-Lower Cretaceous Bazhenov Formation of the West Siberian Marine Basin, Russia

Yuri N. Zanin , Albina G. Zamirailova and Vika G. Eder
Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences Acad Koptyug pr. 3, Novosibirsk, 630090, Russia.

ABSTRACT

Six species of four calcareous nannofossil genera (Ellipsagelosphaera Noël,1965, Watznaueria Reinhardt, 1964, Cyclagelosphaera Noël, 1965 and Tetralithus Gardet, 1955) from the black shale Bazhenov Formation of the West Siberian marine basin are described in layers, transitional from the Upper Jurassic (the Volgian-Tithonian Stage) to the Lower Cretaceous (the Berriasian Stage). Stratigraphically, the presence of the species of all genera in the Bazhenov Formation corresponds to the world data. Three new species (Ellipsagelosphaera bazhenovi Zanin sp.n., Watznaueria sp. and Tetralithus isopelxiros Zanin sp.n. have been determined.

Keywords:

Calcareous nannofossils, upper Jurassic-lower cretaceous, Siberia, Russia.