The Taimyr Peninsula and the Severnaya Zemlya archipelago, Arctic Russia: a synthesis of glacial history and palaeo-environmental change during the Last Glacial cycle (MIS 5e–2)

Abstract

We here suggest a glacial and climate history of the Taimyr Peninsula and Severnaya Zemlya archipelago in arctic Siberia for the last about 150 000 years (ka). Primarily it is based on results from seven field seasons between 1996 and 2012, to a large extent already published in papers referred to in the text – and on data presented by Russian workers from the 1930s to our days and by German colleagues working there since the 1990s.Although glaciations even up here often started in the local mountains, their culminations in this region invariably seems to have centred on the shallow Kara Sea continental shelf – most likely due to expanding marine ice-shelves grounding there, as a combined effect of thickening ice and eustatically lowered sea-levels.The most extensive glaciation so far identified in this region (named the Taz glaciation) took place during Marine Isotope Stage 6 (MIS 6), i.e. being an equivalent to the late Saale/Illinoian glaciations. It reached c. 400 km southeast of the Kara Sea coast, across and well beyond the Byrranga Mountain range and ended c. 130ka. It was followed by the MIS 5e (Karginsky/Eemian) interglacial, with an extensive marine transgression to 140 m above present sea level – facilitated by strong isostatic downloading during the preceding glaciation. During the latest (Zyryankan/Weichselian/Wisconsinan) glacial cycle followed a series of major glacial advances. The earliest and most extensive, culminating c. 110–100ka (MIS 5d–5e), also reached south of the Byrranga mountains and its post-glacial marine limit there was c. 100m a.s.l. The later glacial phases (around 70–60ka and 20ka) terminated at the North Taimyr Ice Marginal Zone (NTZ), along or some distance inland from the present northwest coast of Taimyr. They dammed glacial lakes, which caused the Taimyr River to flow southwards where to-day it flows northwards into the Kara Sea. The c. 20ka glacial phase, contemporary with the maximum (LGM) glaciation in NW Europe, was this glacial cycle's least extensive one up here – probably an effect of precipitation shadow caused by the major glaciations to the west. From the Kara Sea shelf this advance only reached c. 100 km inland, over some limited parts of NW Taimyr. The Severnaya Zemlya islands were only locally glaciated at this time.The lowlands south of the Byrranga Mountains have been a terrestrial “Mammoth steppe” environment during the last c. 50ka and periglacial permafrosted sediments here have preserved excellent information on its megafauna and vegetation. The latter, according to new DNA-data, had considerably more (for grazing animals nourishing) flowering plants growing than earlier pollen-based (grass dominated) spectra have suggested.