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Glacial Landforms and the Age of Deglaciation in the Tiksi Area, East Siberia

1992; Taylor & Francis; Volume: 74; Issue: 4 Linguagem: Inglês

10.2307/521428

1468-0459

M. G. Grosswald, Wibjörn Karlén, Zh. G. Shishorina, Anders Bodin,

Geological Studies and Exploration

ABSTRACTABSTRACTTiksi area in eastern Siberia has generally been believed to have remained ice-free throughout the entire Ice Age. However, new glacial geomorphological research in the region has revealed evidence of a former ice sheet centered on the East Siberian shelf and reaching as far as Tiksi Bay. Among indications supporting this concept are fresh-looking U-shaped valleys, giant flutes, rock drumlins and other ice-erosional features, as well as systems of glacio-tectonic ridges coupled with rock basins ("hill-and-hole pairs")—all attesting to a former ice motion in a northeast-southwest direction.The work carried out in May 1990 by a Swedish-Soviet field party was aimed at resolving the chronology of the latest glacial events in the Tiksi area. To this end, the bottom sediments of two lakes joined by glaciotectonic ridges were cored, analysed and AMS-14C dated. The ages of 6450+/-110 6870+/-80 and 8500+/-160 radiocarbon years BP were minimum dates obtained for the beginning of lacustrine sedimentation in the basins. This suggested that the last icesheet glaciation of the area had been of Late Pleistocene age.