Geology

The results of interpretation of biostratigraphic separation of santonian-campanian deposits of the Saratov right-bank Volga region, on the example of earlier conducted detailed and complex investigation of separation near the village Mezino-Lapshinovka have been presented. The ideas of realiability of variants of the detailed (on the level of subtages) subdivision of santonian substage in reference to the territory of the Volga right-bank have been given. 

On the basis of the analysis of the literature on studying gulling in territory of Saratov and vicinities the basic techniques and results of researches for more than 130-years period, and also directions of modern studying are noted. The modern level of a level of scrutiny gulling territories is certain. 

The mass extinction of life in the sea and on land 251 million years ago, at the Permian-Triassic boundary, was undoubtedly the largest mass extinction of all time. Sedimentological and geochemical evidence shows that global temperatures rose, that there was extensive oceanic anoxia, and that there was massive erosion of sediment, especially soils, from the land. These phenomena might have been a consequence of the massive eruptions of the Siberian Traps, which produced carbon dioxide, and greenhouse gas, as well as acid rain, which killed plants and led to stripping of soils.

The Gremyachinskoye sylvinite field lies in the south of the Volga monocline, to the northeast of the Severo-Kotelnikovskij overthrust. Halogen beds from the field were examined. The study has provided grounds for correlating the field potassium-bearing horizon with the Pogozhskaya rhythmic member from the Volga monocline. The halogen bed formation was influenced by the principal water area of the salt-generating basin in the east and by the calcium chloride brines discharged along the disjunctive dislocations limiting the overthrust zone.