Late Wisconsinan glaciation of southern Eureka Sound: evidence for extensive Innuitian Ice in the Canadian High Arctic during the Last Glacial Maximum

Southern Eureka Sound was originally proposed as the centre of an Innuitian Ice Sheet in the Canadian High Arctic at the Last Glacial Maximum (LGM) ba sed largely on the pattern of Holocene emergence. This paper focuses on the glacial geological evidence for such an ice sheet in the region. Granite d ispersal trains and ice-moulded bedrock record regional, westward flow of w arm-based ice into Eureka Sound from SE Ellesmere Island. Regional ice was coalescent with local ice domes on inter-fiord peninsulas. Marine limit in the form of raised deltas, beaches and washing limits formed during deglaci ation of the regional ice. Throughout southern Eureka Sound, marine limit d ates less than or equal to 9.2 ka BP, indicating that ice commenced retreat during the early Holocene. Ice-divides were located along the highlands of central Ellesmere and Axel Heiberg islands, from which ice inundated Eurek a Sound, flowing north and south along the channel. Regional radiocarbon da tes on marine limit show that deglaciation occurred in two steps. Initial b reak-up and radial retreat of ice from Eureka Sound to the inner fiords was rapid and preceded stabilisation along adjacent coastlines and at ford hea ds. Two-step deglaciation is also reflected in differences in glacial geomo rphology between the inner and outer parts of many fiords. A prominent belt of fiord-head glaciogenic landforms, long proposed to mark the last glacia l limit, is re-interpreted to record initial, stabilisation of ice margins due predominantly to bathymetric control. (C) 2000 Elsevier Science Ltd. Al l rights reserved.