关键词: 拉斯曼丘陵,冰川作用

Abstract:

The Larsemann Hills are a series of gneiss islets and peninsulas extending into Prydz Bay, between the Amery Ice Shelf and the Sorsdal Glacier. The hills are ice free and form an area of approximately 200km 2 at 69°21′ -69° 28′ S and 76°00′-76°25′E on the Ingrid Christensen Coast of Princess Elizabeth Land, East Antarctica. The hills had been covered by ice sheet as early as Early Oligocene, and the ice sheet was the thickest in the Late Oligocene. Since the Miocene, ice sheet began to be thinner and retreat but covered the hills also. The glaciation scale of the quaternary is far inferior to the Tertiary. The thickness of ice sheet exceeds 170m and the margin thickens about 30 km at 18 ka B.P.. The time of deglaciation and exposed rocky land has been outlined at 10 ka B.P..The islets of the Larsemann Hills were ice free by 6.5ka B.P., and the rate of retreat was 2-3 m/a. By 5.0ka B.P.,50% of the hills were exposed and ice retreated at 1.0-1.5m/a. After 5.0 ka B.P. the rate of retreat did not exceed 0.8-1.0 m/a to its present position.