GLACIER DYNAMICS AND PALEOCLIMATIC CHANGE DURING THE LAST GLACIATION OF EASTERN ELLESMERE ISLAND, CANADA

A 300 km transect along the east coast of Ellesmere Island fills a maj or gap in the late Quaternary data base of the Canadian High Arctic. T he last glacial maximum (LGM) is marked by prominent moraines and melt water channels that terminate within 30 km of modern ice margins. Shel ls in glaciomarine deposits, collected beyond the LGM, indicate deglac iation by more extensive ice prior to 35 ka BP. More than 60 C-14 date s from glaciomarine sediments provide a chronology for past ice dynami cs during the LGM. To the north, while many areas remained ice free du e to severe aridity, several glaciers remained in contact with the sea until 7.1 ka BP. Farther south, most glaciers reached the coast and s ignificantly infilled several fiords. This southward increase in glaci er extent is due to larger glacial catchment basins and increased prec ipitation towards storm tracks in northern Baffin Bay. The earliest da tes on deglaciation along the transect range from 8.1 to 7.7 ka BP. In itial retreat was controlled by the extent of the marine-based ice mar gins, which were destabilized by calving. Once landward of the sea, ma ny glaciers stabilized until similar to 6.5 ka BP. Considerable interf iord variability in glacier dynamics is apparent. A paleoclimatic mode l is proposed linking past glacier activity in the Canadian High Arcti c with the available ice core record. Greenland ice cores show that co lder intervals, with depleted delta(18)O, were associated with reduced precipitation and storminess, which may have constrained ice buildup prior to similar to 15 ka BP. In contrast, the abrupt rise in delta(18 )O after similar to 15 ka signals the onset of regional warming associ ated with increased storminess and precipitation (up to 200%). This ma y have occasioned a late buildup of High Arctic glaciers, which remain ed close to the last ice limit well into the Holocene.