Application of palynology in the stratigraphy of quaternary deposits of the U.S.S.R.

Abstract

The analysis of the data on Pleistocene and Upper Pliocene forest floras in the territory of the U.S.S.R. showed that they can be subdivided into three successive age groups on the basis of the same criterion, the generic composition of geographical groups of dendroflora. Group I is characterized by the presence of American-East Asian and American-Mediterranean-Asian genera: prenemoral flora with similar composition throughout the continent. Group II is characterized by the presence of the only group of genera which is absent in the modern flora of the region: protonemoral flora in Europe and the Far East with American-Mediterranean-Asian genera and quaiboreal in Siberia and Kamchatka with American-Euro-Asian genera. Group III is characterized by the total absence of the genera which are not represented in the modern local flora: nemoral in Europe and the Far East and boreal in Siberia and Kamchatka. The stratigraphic position of the prenemoral flora corresponds to the Lower Pleistocene and the Upper Pliocene. Paleomagnetic evidence of the Ural and Middle Asia indicates that the prenemoral flora existed during the Matuyama epoch. The protonemoral flora in Europe and the Far East corresponds to the Middle Pleistocene interglacials. Nemoral and boreal floras correspond to the Upper Pleistocene and Holocene. Paleomagnetic data on the Kama region, Middle Asia and the Far East indicate that floras of groups II and III existed during the Brunhes epoch. For more detailed subdivision of the deposits other criteria should be used.