Late Quaternary climatic changes around the Elephant Islands, Antarctic Peninsula

Abstract

Sixty-seven species of diatoms of 28 genera were identified in Core GC03-C2 acquired from the north slope of Elephant Island, Antarctic Peninsula. The number of diatom valves per gram of dry sediment ranged from 0.2~17.3×107g？1, and these were dominated by Fragilariopsis kerguelensis (65.8%). Diatom assemblage analysis reconstructed the Quaternary paleoclimatic change the Elephant Islands. Four diatom assemblage zones were identified according to the frequency of critical taxa as follows: zone I, from 830 to 710 cm (Antarctic Cold Reversal);zone II, from 700 to 550 cm (Deglaciation zone);zone III, from 540 to 260 cm (warm period;Holocene);and zone IV, from 250 to 0 cm (cool period;Holocene). The high abundance of reworked species includes Actinocyclus ingens, Denticulopsis hustedtii, D. praedimorpha, and D. dimorpha appeared in Zone I by turbidity currents and ice rafting in the area during the glaciations-deglaciation event.