Evolution of the Antarctic glaciated continential margin

grantor: University of TorontoThis thesis presents (a) a critical review of existing glacial marine depositional models for the Antarctic continental margin and (b) an analysis of data from Ocean Drilling Program Leg 178 (Feb.-April 1998) which drilled the Antarctic Peninsula continental margin. Present-day 'interglacial' conditions of extensive ice shelves, servere cold, minimal meltwater production and sediment starvation on the margin are unique to Antarctica. Early work suggests such 'polar' conditions are representative of ancient Pleistocene and pre-Pleistocene environments in Antarctica. Litho- and biofacies data from Ocean Drilling Program Leg 178 provides important details regarding depositional processes responsible for glaciated continental shelf topsets and slope foresets in Antarctica. Topset deposits are constructed of deformation till reflecting large-scale subglacial reworking of pre-existing glacial and marine sediment across the shelf during ice sheet expansion and decay. Foreset deposits are composed of shelf deposits reworked downslope as debris flows and turbidity currents. Similar successions have been identified from other Pleistocene and pre-Pleistocene glacially-influenced continental margins. This work indicates that modern 'polar' conditions of Antarctica are not representative of ancient conditions.M.Sc