Fluctuations of the Weichselian ice sheet in SW Iceland: A glaciomarine sequence from Sudurnes, Seltjarnarnes

Sedimentological and palaeontological studies in Reykjavik, SW Iceland, show that the glaciation history during the Late Pleistocene was characterized by a fluctuating glacier flowing WNW from Reykjanes Peninsula. New ¹⁴C dates show that marine deposition took place in coastal regions during at least three interstadials, corresponding to the Alesund, the Bolling, and the Allerod in Scandinavia. The oldest of these interstadials is dated to ca. 28,000 ¹⁴C years BP and represents the oldest Weichselian interstadial registered in Iceland up to now. Recent studies in Gardabaer, SW Iceland, show marine transgression during the Bolling. Earlier work in Fossvogur, Reykjavik indicates that the Allerod-Younger Dryas boundary did not coincide with a marked change in the water masses in SW Iceland. Sedimentological studies reveal a relatively high energy environment with near-shore and glaciomarine deposition and a period of glacial expansion during the Younger Dryas. The macrofauna, foraminifera, and ostracod faunas from sediments dated to the late Younger Dryas on Sudurnes have been analysed and indicate low arctic to high boreal conditions. The Sudurnes data show that the Younger Dryas glaciation in the Reykjavik area took place in a glaciomarine environment. The youngest dated sediments of the Sudurnes sequence probably post date this glacier expansion.