| mhorn | Дата: Tuesday, 14.02.2012, 12:04 | Сообщение # 1 |
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| Dzyuba O. S. (2012) Belemnites and biostratigraphy of the Jurassic/Cretaceous boundary deposits of the northern East Siberia: new data on the Nordvik Peninsula // Stratigraphy and Geological Correlation, Vol.20, P.53-72.
Pdf: http://rogov.zwz.ru/Dzyuba,2012_belemnites_JK_boundary.pdf
The study of new collections from the UrdyukKhaya Cape (Nordvik Peninsula) made it possible to specify the taxonomic composition of belemnites from th e Volgian and basal Ryazanian in northern East Siberia. Cylindroteuthis knoxvillensis Anderson, 1945, C. cf. newvillensis Anderson, 1945, and Arctoteuthis tehamaensis (Stanton, 1895) known from northern California, as well as the new species C. venusta sp. nov. and A. britanna sp. nov. are first described from the Arctic region . Belemnite stratigraphy of Jurassic–Cretaceous boundary layers is fundamentally revised, allowing a new refined version of their scale to be prop osed as a Boreal standard. Two independent successions of biostratigraphic units are defined in the section interval spanning the uppermost Middle Volgian Substage to the basal Ryazanian Stage: (1) Liobelus russiensis Zone, Lagonibelus gustomesovi and Arctoteuthis porrectiformis beds; (2) Lagonibelus napaensis, Arctoteuthis tehamaensis, and Cylindroteuthis knoxvillensis zones.
Middle Jurassic - Lower Cretaceous ammonites & aptychi
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