%0 Journal Article %T A condensed succession at the Jurassic/Cretaceous transition in a shallowing basin on the eastern Russian Platform %A Zorina Svetlana O. %A Ruban Dmitry A. %A Van Loon Tom A.J. %J Geolo£¿ki Anali Balkanskog Poluostrva %D 2009 %I Faculty of Mining and Geology, Belgrade %R 10.2298/gabp0970001z %X The eastern periphery of the Russian Platform houses an exceptional record of the Jurassic/Cretaceous transition, which is represented by very thin sandstone beds. The presence of glaucony grains, phosphorite concretions and shark teeth indicates that the transitional sediments constitute a condensed succession, although the allochtonous origin of the glaucony grains in itself is not a reliable indicator. The combination with thin ammonite zones and a strongly diminished sedimentation rate, as low as ~0.05 cm/ka are, however, convincing evidence. The Jurassic/Cretaceous transitional deposits accumulated in a basin the depth of which decreased simultaneously with a global eustatic sea-level fall. This coincidence suggests that condensed successions may form in shallowing environments, which contradicts the sequence-stratigraphic concept. Considering the character of the sediments under study, it appears that both stratigraphic and taphonomic condensation patterns occur in this part of the eastern Russian Platform. %K condensed succession %K shallowing %K ammonite zones %K Jurassic %K Cretaceous %K Russian Platform %U http://www.doiserbia.nb.rs/img/doi/0350-0608/2009/0350-06080970001Z.pdf