Abstract

Fossiliferous raised marine deposits occur around Home Bay, east Baffin Island, Northwest Territory. We developed a late-glacial chronology on the bases of 32 radiocarbon dates and morphostratigraphic evidence. In addition, the similarity of observed and predicted postglacial emergence curves enabled development of techniques that provided age estimates of marine limits throughout the area, and allowed construction of an isochron map for deglaciation.

Retreat of the fiord glaciers was relatively rapid (average 27 m yr−1) between 10,000 and about 8000 B.P. Evidence for a major readvance of the glaciers about 8000 years ago includes moraines overlying marine clay, elevation of associated raised delta deposits relative to local marine limits, and a prominent and extensive moraine, the Ekalugad Moraine (new name). Related radiocarbon dates are similar in age to the Cockburn Moraine of Arctic Canada. Another moraine, dated about 6800 B.P., is of similar age to the Isortoq Moraine of west Baffin Island. Valley glaciers from the main interior ice sheets were still descending to near sea level only 4500 to 4000 years ago. Disappearance of the interior ice sheet west of Home Bay apparently coincided with, or at least preceded, the growth of the local mountain ice caps.

Marine limit elevations are a function of distance from the continental shelf (a measure of ice thickness) and date of deglaciation; elevations, consequently, incline inland to the outer limit of the Ekalugad Moraine (from 40 m to a maximum of 91 m) and then decline inland, thus reflecting the slow deglaciation and the importance of restrained rebound. Isobases are oriented from 140° to 320°. Glacio-isostatic recovery has led to the warping of former marine planes. Maximum tilt on the oldest strandline (8600 years old) is 1.8m km−1.

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