Estimation of Paleo-ice Sheet Thickness and Evolution of Landforms in Schirmacher Oasis and Adjoining Area, cDML, East Antarctica

Abstract

Quaternary period has witnessed perceptible climatic change in Schirmacher region, central Dronning Maud Land (cDML), East Antarctica. There were buildup of ice sheet and its recession throughout the period. The Schirmacher Oasis, Baalsrudfjellet, Veteheia and Veten nunataks are the prominent northernmost exposures in cDML area and play a major role in controlling the ice flow in this region resulting in glacial erosional as well as depositional landforms. These developments reveal vital information about the evolution of the region in Quaternary period. Erosional features such as roche-moutonees, glacially polished and abraded rocky outcrops with excellent preservation of glacial striations indicates the paleo-movement of overriding glaciers. Striations are generally preserved on polished surfaces of bedrock exposed on the high lands, however, glacial striations are also preserved over some mafic and resistant hard rocks in low lying areas. In general, the glacial striations indicate north-northeast movement of paleo ice sheet. Majority of the boulders in east-central valley show their longer axis trending in NNE-WSW to NE-SW directions. The cross cutting relation of striations give the changing directions of paleo ice sheet movement. Further, back calculation of depth of indentation and corresponding ice load gives a value of 100 to 500 m thick paleo-ice sheet in different parts of this region, documenting vast deglaciation in this region.