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Research Interests: Archaeology and Geology
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Research Interests: Earth Sciences, Geology, Oceanography, Climate Change, Arctic, and 14 moreHolocene, Quaternary Science, Surface energy balance, History and archaeology, Ocean Circulation, Laurentide Ice Sheet, North America, Atmospheric Circulation, Quaternary Science Reviews, North American, Radiative Forcing, Ice Sheets, Holocene Thermal Maximum, and Calendar year
Research Interests: Archaeology and Geology
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Research Interests: Archaeology and Geology
Research Interests: Archaeology and Geology
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Research Interests: Archaeology and Geology
Research Interests: Archaeology and Geology
Research Interests: History and Archaeology
Research Interests: Archaeology and Geology
Seven new radiocarbon dates pertaining to deglaciation of northern Prince of Wales Island place the margin of the Laurentide Ice Sheet on the island by 11 000 BP. This requires a revision of the proposed age for the Viscount Melville... more
Seven new radiocarbon dates pertaining to deglaciation of northern Prince of Wales Island place the margin of the Laurentide Ice Sheet on the island by 11 000 BP. This requires a revision of the proposed age for the Viscount Melville Sound Ice Shelf of 10 300 – 9880 BP. A revised age of 11 300 – 11 000 BP is suggested.The new dates also require revisions of the proposed Wisconsinan and Holocene history of Banks Island. Shells thought to have been thrust onshore to an elevation of 88 m by the ice shelf on northern Banks Island after 10 600 BP are reinterpreted as undisturbed postglacial marine shells recording a relative sea level of 88 m or more. This, in turn, suggests that the East Coast Sea and Jesse Till are of Late Wisconsinan rather than Early Wisconsinan age and that the Late Wisconsinan glacial limit on Banks Island as figured on the 1968 Glacial Map of Canada, rather than on recent revisions, is essentially correct.
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Some of the most extensive and massive end moraines of Younger Dryas age (1110 14C ka BP) yet recognized in North America occur on Wollaston Peninsula of Victoria Island. On the western part of the peninsula, numerous closely spaced end... more
Some of the most extensive and massive end moraines of Younger Dryas age (1110 14C ka BP) yet recognized in North America occur on Wollaston Peninsula of Victoria Island. On the western part of the peninsula, numerous closely spaced end moraines formed in the interval starting 11 100 ± 100 radiocarbon years ago and ending about 10 50010 200 years ago. Net recession was generally slow throughout and was punctuated by moraine-building and at least two readvances. Recession is mapped with a resolution that is approximately decadal. The moraines form an orderly, nested succession and are consistently associated with westward shedding of meltwater, which formed a sequence of marine-limit deltas. We lack firm, independent proxy-climate evidence needed to assess whether these moraines formed because of cold Younger Dryas climate, rather than because of controls such as topographic setting and water depth, but climatic control seems probable. The moraines evidently retain glacier ice cores, as do most similarly large moraines in the Canadian Arctic Archipelago and northern mainland. They formed along active ice margins when the glacier mass balance on average was only slightly negative. Future melting of ice cores would produce regional hummocky moraine and much basal meltout till more than 10 000 years after deglaciation. Some southern areas of hummocky moraine may have originated as ice-cored moraines formed by active ice margins rather than from extensive regional stagnation.
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... It is marked by the highest kelp jetsam, the highest level of presently active marine depo-sition, and the lowest level of lichen cover. All elevation measurements relate to construc-tural marine features, most of which are of AS DYKE... more
... It is marked by the highest kelp jetsam, the highest level of presently active marine depo-sition, and the lowest level of lichen cover. All elevation measurements relate to construc-tural marine features, most of which are of AS DYKE / 187 1 2 3c 3 rC d 4 u 5
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Deglaciation of northern Baffin Island involved several large ice streams with contrasting histories. Three north‐flowing, marine‐based ice streams were in place during the Last Glacial Maximum, but they retreated at widely varying rates... more
Deglaciation of northern Baffin Island involved several large ice streams with contrasting histories. Three north‐flowing, marine‐based ice streams were in place during the Last Glacial Maximum, but they retreated at widely varying rates during the early and middle Holocene. The Steensby Inlet Ice Stream formed in response to over‐steepening of the ice front during deglaciation of Foxe Basin. It caused an abrupt change, in places a general reversal, of flow about 6 ka BP and operated across its full width for only about 500 years. Nevertheless, it left a distinct subglacial footprint, including an hourglass shaped bedform set. A dense network of till samples from the region of the ice stream reveals a sharp‐sided, pluglike dispersal of carbonate debris that was sustained by erosion in the source area of about 5 mm a−1. The ice stream devolved into valley‐controlled ice streams separated by cold‐based ice over interfluves. The former evacuated debris along valleys and left erosional till scarps along the sides of sliding ice. Post‐ice‐stream end moraines, including the large Gifford Moraine, require later cold‐based flow across the drumlins formed by the ice stream. Copyright © 2008 John Wiley & Sons, Ltd.
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Research Interests: Archaeology and Geology
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Twenty-two pairs of radiocarbon dates on driftwood and bowhead whale (Balaena mysticetus) bones from raised beaches, dates on whale bone and terrestrial plant detritus from a stratigraphie section, and 25 additional dates on whale bones... more
Twenty-two pairs of radiocarbon dates on driftwood and bowhead whale (Balaena mysticetus) bones from raised beaches, dates on whale bone and terrestrial plant detritus from a stratigraphie section, and 25 additional dates on whale bones from the lowest (≤1 ka BP) raised beaches in the eastern Canadian Arctic suggest that a marine reservoir correction of about −200 years is appropriate for normalized age determinations on bone collagen from the bowhead whale in this region. This is less than the correction (−400 years) normally applied to carbonate shells of marine molluscs from this region. The carbon in bowhead collagen appears to be derived from the whales' zooplankton food rather than from marine bicarbonate.
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Research Interests: Geology and Oceanography
Research Interests: Archaeology and Geology
Drumlin fields, or swarms oi hills streamlined in the direction of glacier flow, are common elements of glaciated landscapes. Most are believed to have formed a short distance behind the ice margin just prior to deglaciation and therefore... more
Drumlin fields, or swarms oi hills streamlined in the direction of glacier flow, are common elements of glaciated landscapes. Most are believed to have formed a short distance behind the ice margin just prior to deglaciation and therefore record the final direction of ice ...