Biostratigraphic partition of the upper cretaceous deposits of the Volga upland in the Samara region
In different regions of Russia Mesozoic deposits are promising for oil and gas detection. In recent years in the Volga region again arose the interest of geologists to Mesozoic deposits in connection with the search for hydrocarbons, and in particular with the prospects of sediments on shale gas. Stratigraphically Cretaceous deposits exploded on the basis of Macrofauna (Ammonites and Belemnites). Recently stratification of these deposits is carried out on complexes of microfauna foraminifera. In the course of fieldwork, samples of cretaceous were selected for the study of the microfauna. As a result were found: foraminifera, mollusca, echinoderms and ostrakod. The complex of foraminifera from the Maastrichtian sediments, spread on the Volga Upland in the Samara region, was studied. The description of representatives of genus and species is given. As a result of the analysis of literary sources the scheme of comparison of faunistic zones of the Maastrichtian Stage according to the data of different authors is made, the guiding forms are revealed and it is established that the studied complex of foraminifera is characteristic for the Maastrichtian Stage.