The problem of the non-marine cretaceous strata correlation in the north-east of Russia: the conditions of florogenesis in the volcanic region

Abstract

The most part of the fossil floras from the Cretaceous volcanogenic formations of the North-East of Russia differs significantly in systematic composition from the same-age paleofloras of coastal lowlands. In order to explain the features of their formation, the modern data on the dynamics of vegetation cover on the volcanic plateaus of Central Kamchatka were used. It was shown that in the sites where the paleofloras in geological disposals of the Okhotsk-Chukchi volcanogenic belt were found, there was practically no erosion, but there was the abundance of volcanic material suitable for the formation of disposals. After the massive powerful eruptions, the inland districts of the vast volcanic areas were isolated from the sources of diasporas. Vegetation cover in these areas recovered mainly due to the pool of local species, i.e., maintained as a diasporic sub-climax. The lack of competition from angiosperms contributed to the long-term preservation in such paleofloras the ancient groups of plants and the formation of new taxa on their basis.