| Title | Postglacial tectonic and sea level history of the central Canadian Arctic |
| Download | Downloads |
| Author | Dyke, A S; Morris, T F; Green, D E C |
| Source | Geological Survey of Canada, Bulletin 397, 1991, 56 pages, https://doi.org/10.4095/132168 (Open Access) |
| Image |  |
| Year | 1991 |
| Publisher | Geological Survey of Canada |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Northwest Territories; Nunavut |
| NTS | 46; 47; 48; 49; 56; 57; 58; 59; 66; 67; 68; 69; 76; 77; 78; 79; 86; 87; 88; 89; 340B; 340C; 340F; 340G; 560 |
| Area | Canadian Arctic |
| Lat/Long WENS | -120.0000 -80.0000 84.0000 64.0000 |
| Subjects | geochronology; 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 |
| Illustrations | charts; photographs; graphs |
| Released | 1991 08 01; 2014 06 19 |
| 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 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. |
| GEOSCAN ID | 132168 |
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