Author: Chuanyu (Stephen). Sun
Publisher:
ISBN:
Category :
Languages : en
Pages : 430
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Glacial Lake Hind was a 4000 km2 ice-marginal lake which formed in southwestern Manitoba during the last deglaciation. It received meltwater from western Manitoba, Saskatchewan, and North Dakota via at least 10 channels, and discharged into glacial Lake Agassiz through the Pembina Spillway. Surface sediment outside of the area covered by glacial Lake Hind is dominantly till. There are two types of tills based on their carbonate content and calcite/dolomite ratios: one that has high carbonate content and a low calcium/dolomite ratio (Dh), which occurs east of glacial Lake Hind, and another that has low carbonate content and a high calcite/dolomite ratio (Dl), which occurs north, west, and south of glacial Lake Hind, and may underlie Lake Hind sediments. Four till units have been identified based on carbonate content, texture, and color. They are the Wawanesa till, Souris till, Fairfax till, and Carroll till. Sediments in the Lake Hind basin consist of up to 30 m of silt and clay, 25 m of sand and deltaic gravels. Much of the uppermost lacustrine sand in the central part of the basin has been reworked into aeolian dunes. No beaches have been recognized in the basin. Around the margins, clayey silt occurs up to an elevation of 457 m, and deltaic gravels occur at 434 - 462 m. In addition, there are a total of 12 deltas around the lake basin, and these can be divided into 3 groups based on the elevation of their surfaces: 1) above 457 m along the eastern edge of the basin and in the narrow southern end; 2) between 450 and 442 m at the western edge of the basin; and 3) below 442 m. The earliest stage of glacial Lake Hind began shortly after 12 ka, as a small lake formed between the eastern edge of the Souris Lobe and the western edge of the Red River Lobe in southwestern Manitoba. Two deltas at an elevation of above 457 m were formed in this lake. At the same time, the western edge of the Souris Lobe retreated far enough to allow glacial Lake Souris to expand northward along the western side of the basin from North Dakota; three deltas were built at an elevation of between 457 and 466 m in the Canadian part of this proglacial lake. Continued retreat of the Souris Lobe allowed the merger of glacial Lake Souris with the interlobate glacial Lake Hind. Subsequent erosion of the outlet into the Pembina valley allowed waters in the glacial Lake Hind basin to become isolated from glacial Lake Souris, and four deltas formed between 442 and 450 m by meltwater from the west. Next, a catastrophic flood from the Moose Mountain uplands in southeastern Saskatchewan flowed through the Souris River valley to glacial Lake Souris, in turn, spilling into Lake Hind and depositing another delta at an elevation of about 442 m. This resulted in further incision of the outlet into the deep and wide Pembina spillway, and a new level of glacial Lake Hind was established at 434 m. A second flood through the Souris River valley, this time from glacial Lake Regina, further eroded the outlet; most of glacial Lake Hind was drained as a result of this flood except for the deeper northern part. Coarse gravel was deposited by this flood, which differs from previous flood gravel because it is massive and contains less shale.
Author: Chuanyu (Stephen) Sun
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Author:
Publisher:
ISBN:
Category : Agassiz, Lake
Languages : en
Pages : 114
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Author: L. A. Dredge
Publisher:
ISBN:
Category : Political Science
Languages : en
Pages : 100
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The report and accompanying map describe and interpret the terrain conditions across 48,000 km2 of the coast and hinterland of Hudson Bay. The surface mapping of materials was combined with a study of river exposures in order to reconstruct the preglacial and glacial evolution of the landscape, and postglacial changes in permafrost, climate, and sea level. The geological interpretation was used to locate anomalously high concentrations of minerals of economic value, including gold and uranium, assess aggregate sources, identify areas of sensitive permafrost terrain, and to predict future environmental change.
Author: Warren Upham
Publisher: W.F. Brown
ISBN:
Category : Agassiz, Lake
Languages : en
Pages : 178
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Author: Patrick Douaud
Publisher: University of Regina Press
ISBN: 9780889771468
Category : Ecology
Languages : en
Pages : 218
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Landscapes of the Northern Great Plains have been constantly changing, but never so rapidly as under modern conditions of economic affluence and technological development. This change is multifaceted and has an impact not only on the fabric of culture and its perception of landscape, but also on the ecology and physical landforms. Multidisciplinary research has therefore become an important tool in identifying the influences that human activities have, not only on cultural landscapes but on biophysical ones as well. This collection of articles, originating in a conference held at the Royal Saskatchewan Museum in April 2000, focuses on just such an integration of research concerning the Great Plains of North America and involving the disciplines of geology, archaeology, biology, geography, sociology, and agriculture.
Author: Manitoba. Geological Survey
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 472
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Author: Canadian Institute of Mining and Metallurgy
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 822
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Author: David J. A. Evans
Publisher: Routledge
ISBN: 1444119141
Category : Science
Languages : en
Pages : 297
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Sediments are the most valuable form of physical evidence for past Earth surface processes. They have the potential to build up an archive of events and provide a window into the past. Through careful examination of sediments the shifting patterns of surface processes across space and time are revealed, allowing us to reconstruct past environments and environmental change. A Practical Guide to the Study of Glacial Sediments is a guide to the standard techniques employed to read the sedimentary record of former glaciers and ice sheets. It demonstrates that the often complex and fragmentary glacial sedimentary record can, when examined systematically and rationally, provide detailed insights into former environments and climates in places where no other evidence is available. The complementary techniques covered in this book include: facies description, grain size analysis, clast form assessment, clast macrofabric analysis, micromorphology, particle lithology and assessment of engineering properties. They yield consistent and meaningful results in a range of glacial depositional environments throughout the world, from the high Arctic to the Himalayas. A Practical Guide to the Study of Glacial Sediments provides students and researchers with a clear and accessible guide to recording and interpreting glacial successions wherever the location.
Author: Alan V. Jopling
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 334
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