LATE QUATERNARY DUNE FORMATIONS (D’OLKUMINSKAYA SERIES) IN CENTRAL YAKUTIA (PART 2)
A.A. Galanin, M.R. Pavlova
Melnikov Permafrost Institute, SB RAS, 36, Merzlotnaya str., Yakutsk, 677019, Russia; agalanin@gmail.com
The study of generalized geologic section of the Kysyl-Syr dune massif (tukulan) in the lower Vilyuy river basin (Central Yakutia) on the basis of new 14C dates from 27 samples and biostratigraphic data allowed new insights about the Late Quaternary evolution of paleogeographic conditions of dune-forming processes in the region. Based on the previously published results of the studies of key-sections of dune sediments in different parts of Central Yakutia and new absolute age dates, the authors have concluded that the widespread in Central Yakutia dune sediments (D’olkuminskaya Series) formed at different hypsometric levels (river terraces, watersheds) over a time spanning from the latest Karginsky termochron (late MIS-3) till the beginning of the Holocene (between 35 and 10 ka BP) under conditions of severe aridization and desertification of the area. The dune stabilization by soil-vegetation cover occurred during the Boreal optimum of the Holocene (12–6 ka). The modern unvegetated dune massifs are interpreted to have formed not more than 1 thousand years ago, due to dramatic climatic changes associated with the Little Ice Age.
Dunes, eolian formations, grain size analysis, mineralogy, absolute age, palynology, cryolithozone, D’olkuminskaya Series, Quaternary period