Early Holocene environments on October Revolution Island, Severnaya Zemlya, Arctic Russia

Pollen, palynomorphs, and rhizopods were studied from several < 1 m thick, peaty and silty sediment sections on southwestern October Revolution Island, Severnaya Zemlya. Six AMS radiocarbon ages from the sections show that peat accumulation started at ca. 11,500 and stopped after 9500 cal. yr BP, consistent with several previously reported 14 C ages. Open steppe-like vegetation existed on the island during the late Glacial, shortly before the Pleistocene/Holocene transition. Environmental conditions on the island were most favourable for local biota during the early Holocene, ca. 11,500-9500 cal. yr BR when tundra-like sedge-grass communities dominated the vegetation. Low shrub tundra associations with dwarf birch and willow grew in more wind-sheltered localities. The temperatures during the growing season were at least 4 degrees C higher than today. The Vavilov Ice Cap was at or behind its present margins. Environmental conditions in the region changed significantly ca. 9400 cal. yr BP as a result of colder and drier conditions, when vegetation became similar to the modern, sparse lichen-moss-grass cover. (C) 2008 Elsevier B.V. All rights reserved.