Marine palynological researches in the U.S.S.R.

Abstract

During recent years, marine palynological work in the U.S.S.R. has substantially increased. Research has been carried out in the Sea of Okhotsk, the Japanese Sea, the Black Sea, the Sea of Azov, and the Mediterranean Sea, as well as in the western Pacific. A detailed study of the assemblages of spores and pollen of terrestrial plants in the surface layer of the sediments enables us to form an idea of the specific features in the formation of spore-and-pollen spectra in marine sediments. This is helpful to the interpretation of the spore and pollen spectra from ancient marine deposits. Spore-and-pollen spectra from the cores of marine deposits can be well correlated with the data obtained through spore and-pollen analysis of samples collected on the surrounding land. Owing to specific conditions under which the formation of deposits in marine environments takes place, spectra of marine deposits differ, as a rule, from the spectra of continental deposits. They contain much more Pinus pollen and have a lower content of pollen belonging to broad-leaved trees and grasses. The method of spore-and-pollen analysis should be combined with other methods: lithological, studies of the granulometric and mineralogical composition, micropalaeontological methods using Foraminifera, diatoms and other organisms, absolute age determinations, etc. Complex investigations supply the fullest picture of the palaeogeography of the basins which are studied. Unlike these other studies, palynological research gives an idea of the changes in the vegetation cover on the neighbouring land. Moreover, the composition of the flora is a most sensitive indicator of the climate and climatic fluctuations.