The Vanishing record of eperic seas, with emphasis on the late creatacous “Hudson Seaway”
Abstract The geological past differs from the present in many respects; one of the most obvious is the extent of epeiric, or epicontinental, seas that flooded broad areas of continental crust. Modern examples do exist including Hudson Bay and the Baltic Sea, but most shallow seas today are limited t...
| Main Authors: | , |
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| Format: | Book Part |
| Language: | unknown |
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Oxford University PressNew York, NY
1998
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| Online Access: | http://dx.doi.org/10.1093/oso/9780195112450.003.0007 https://academic.oup.com/book/chapter-pdf/52433458/isbn-9780195112450-book-part-7.pdf |
| Summary: | Abstract The geological past differs from the present in many respects; one of the most obvious is the extent of epeiric, or epicontinental, seas that flooded broad areas of continental crust. Modern examples do exist including Hudson Bay and the Baltic Sea, but most shallow seas today are limited to shelf regions which average about 100 km in width. This means that oceanic salinities and temperatures extend across the shelf to the coast in most regions because there is little impediment to the mixing of water masses. In the Cretaceous, by contrast, the Western Interior Seaway invaded 5000 km across North America with depths in the 200 m range, yielding an aspect ratio of 25,000:1. With such a geometry, water masses within the seaway were dictated by local climate patterns (Slingerland et al., 1996) while at the same time they must have had important feedback effects on atmospheric circulation. Large water bodies, including lakes and sea-ways, have an ameliorating effect on climate because they retain heat relative to the more reflective land surface. |
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