CGRG Bibliography of Canadian Geomorphology
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Author : Dyke, A.S.; Morris, T.F.; and Green, D.E.C.
Date : 1989
Title : Abstracts of the 18th Annual Arctic Workshop, April 13-15, 1989 : theme : Global environmental change and the Arctic. - Lethbridge, Alta.
Publication : Abstracts of the 18th Annual Arctic Workshop, April 13-15, 1989 : theme : Global environmental change and the Arctic. - Lethbridge, Alta.
Issue :
Page(s) :
Abstract
More than 130 new radiocarbon dates form the basis for 14 emergence curves for Prince of Wales and adjacent smaller islands. These curves and 14 additional curves from a large surrounding area are the primary basis for a set of central Arctic isobase maps. During and just after deglaciation the Boothia Arch was reactivated, producing 60-120 m of relief on the regionally elevated 9.3 ka shoreline. This deformation could have the form of a symmetrical ridge or a ridge with a fault zone on its western side. The ridge is flanked to the west by a large isobase plateau where the emerged 9.3 ka shoreline has little gradient. The 8 ka and younger shorelines are not affected by the Boothia Arch, but the Prince of Wales Island isobase plateau persisted as the predominant regional isobase feature throughout postglacial time. Since 8 ka all of Prince of Wales Island has emerged without delevelling of shorelines, a glacioisostatically abnormal pattern.We propose a Holocene block tectonics hypothesis: that postglacial rebound of the archipelago involved movement of a mosaic of blocks, some tilting, others not tilting. Small postglacial lineaments on eastern Prince of Wales Island may indicate that minor tectonism has continued until present. The emergence history of Prince of Wales Island since 8 ka can be described by a single exponential least squares regression curve based entirely on 41 driftwood dates. Addition of two select shell dates produces a curve for the area of earliest deglaciation at about 11 ka. The curve has narrow 99 per cent confidence limits, explains 94.72 per cent of data variance and has a correlation coefficient of 0.97. The half-response time, the time during which 1/2 of remaining emergence is accomplished, is 2000 years.
Bibliography of Canadian Geomorphology