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TitlePostglacial tectonic and sea level history of the central Canadian Arctic
AuthorDyke, A S; Morris, T F; Green, D E C
SourceGeological Survey of Canada, Bulletin 397, 1991, 56 pages, (Open Access)
PublisherGeological Survey of Canada
Mediapaper; on-line; digital
File formatpdf
ProvinceNorthwest Territories; Nunavut
NTS46; 47; 48; 49; 56; 57; 58; 59; 66; 67; 68; 69; 76; 77; 78; 79; 86; 87; 88; 89; 340B; 340C; 340F; 340G; 560
AreaCanadian Arctic
Lat/Long WENS-120.0000 -80.0000 84.0000 64.0000
Subjectsgeochronology; sedimentology; tectonics; surficial geology/geomorphology; structural geology; sea level changes; glaciology; glacial history; glacial features; ice sheets; glacial deposits; radiocarbon dates; radiometric dates; folds; structural features; ice retreat; sample preparation; postglacial emergence; postglacial evolution; tectonic interpretations; tectonic history; Parry Island Fold Belt; Boothia Arch; Churchill Province; Cornwallis Fold Belt; Ellesmerian Orogeny; Eureka Sound Group; Eurekan Orogeny; Wisconsin Glaciation; Laurentide Ice Sheet; Paleozoic; Cretaceous; Mesozoic; Tertiary
Illustrationscharts; photographs; graphs
Released1991 08 01; 2014 06 19
AbstractMore 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 is abase maps. During and just after de glaciation 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 on 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 ofWales island isobase plateau persisted as the predominant regional isobasefeature throughout postglacial time. Since 8 ka all of Prince of Wales Island has emerged without de levelling 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 postglaciallineaments on eastern Prince ofWales Island may indicate that minor tectonism has continued until present. The emergence history of Prince ofWales I stand 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 de glaciation at about 11 ka. The curve has narrow 99% confidence limits, explains 94.72% of data variance, and has a correlation coefficient of0.97. The half-response time- the time during which one half of remaining emergence is accomplished- is 2000 years.