The last ice age in the northern Russian Plain: correlation problems

Abstract

This overview attends to the cardinal correlation problem of the main environmental events of the last glacial cycle of the Russian Plain north of 56°N. The data for differentiation between the features of Late Valdai glaciation in the northwestern Russian Plain and of Early Valdai glaciation in the Timan-Pechora region are presented. Short-term standstills of the retreating last Scandinavian glacier inferred from numerous instrumental dates in the west of the Russian Plain are underlined. Two stages of earlier ice advances in the Arctic are identified by multiple optically luminescence measurements and supported by cosmogenic exposure dating of alpine moraines in the Polar Urals. The comparison of forested environments of the Middle Valdai `megainterstadial` published for Central Russia with better studied periglacial landscapes of the Central and Western European flatlands reveals their poor compatibility. A possible reason is the scarce and often too young radiocarbon dates employed in the 1980-s for correlation of pollen diagrams. Subsequent international research of the Russian northern Pleistocene yielded hundreds of more reliable dates obtained by advanced radiocarbon technology and by modern methods of luminescence, uranium series and cosmogenic isotope analyses. The new chronological results in main sections of the northeastern Valdai formations along with their palaeoclimatic signatures are parallel to the well-dated treeless periglacial environments of Central and Western Europe. The palaeogeographic incompatibility of the earlier deduced forested landscapes of the Valdai `megainterstadial` with the last Pleniglacial of Western Europe, as well as with the cold interstadials of the Russian North, calls for redating the Middle Valdai sediments of Central Russia by modern technologies.

Keywords:

palaeogeography, northern Russia, Late Pleistocene, Middle Valdai, megainterstadial, correlation