New stratigraphic and palaeogeographic data on Upper Jurassic to Cretaceous deposits from the eastern periphery of the Russian Platform (Russia)

The Late Jurassic and Late Cretaceous were periods when, after prolonged continental erosion, stable marine sedimentation took effect on the Russian Platform. The sediments which accumulated have diverse lithological compositions and a mixture of transient and endemic faunas. Lithological diversity and a wide variety of facies has led to problems in stratigraphical correlation of Late Mesozoic sequences and discrepancies in palaeogeographical reconstructions. Different faunal groups belonging to a wide variety of palaeozoogeographic provinces exist within these deposits. Therefore, we use all available microfossils (radiolarians, foraminiferas, nannoplankton) and macrofossil groups (ammonites, buchias, inoceramides) in order to establish the synchronicity of anoxic and other events, to propose biostratigraphic zonations and model the palaeogeography for Late Jurassic: lower Kimmeridgian and middle Volgian as well as Cretaceous time. We suggest that the Peri-Tethys of Eastem Europe is a unique area in which to solve the problem of stratigraphic correlation as it incorporates both Boreal and Transitional to Tethyan palaeoclimatic provinces.