HOLOCENE DEGLACIATION, SEA-LEVEL CHANGE, AND THE EMERGENCE OF THE WINDMILL ISLANDS, BUDD COAST, ANTARCTICA

A Holocene deglaciation sequence for Hie Windmill Islands was determined from the 14C age of raised marine shorelines, lake-bottom sediments, and Adelie penguin remains found in abandoned rookeries. A north-south gradient in the elevation of the upper marine limit was observed, with the highest marine limit (31-32 m) observed on Browning Peninsula and Holl Island at the southern edge of the islands. Correspondingly, the southern islands were found to have been deglaciated by 8000 (corr.) yr 6.P. while the northern islands were deglaciated by 5500 (corr.) yr BP. Isostatic uplift rates were calculated as 0.5 to 0.6 m/100 yr, with an estimated total uplift of around 53 m which indicates late Pleistocene ice sheet thicknesses of 201) and 400 m over the islands and adjacent Petersen Bank, respectively. The margin of the Late Pleistocene grounded ice sheet extended an estimated 8-15 km offshore which coincides with the location of the 200 m isobath. © 1993 by Academic Press, Inc.