Holocene History of a Portion of Northernmost Ellesmere Island
Keywords: Long-tailed Jaegers
AbstractRadiocarbon dates and glaciological features of the Ward Hunt area along northernmost Ellesmere Island suggest the following chronology, which is consistent with worldwide climatic oscillations: 1) 10,000-4100 B.P.: deglaciation, and development of several marine levels, particularly one now 40 m above sea level, at 7500 ± 300 B.P.; 2) 4100-2400 years B.P.: climatic deterioration, glacial readvance and formation of ice shelves; 3) 2400-1400 years B.P.: general climatic amelioration; development of dust ablation horizon on Ward Hunt Ice Shelf, glacial retreat; 4) 1400 B.P.-present: climatic deterioration, with renewed thickening of Ward Hunt Ice Shelf, and beginnings of growth of ice rises; the last-mentioned experienced maximum growth in the interval between 350-170 years ago; slight glacial readvance. The isostatic rebound curve for northernmost Ellesmere Island differs from that of the Tanquary Fiord area 80 miles (128 km) to the south because of differing Pleistocene ice thicknesses. We estimate these to average at least 600 m for the former area and 1800 m for the latter.