Late Quaternary Sea Level Changes on Brock and Prince Patrick Islands, Western Canadian Arctic Archipelago
Emerged shorelines are few and poorly defined on Prince Patrick and Brock islands. The sparse radiocarbon dates show emergence of only 10 m through the Holocene on the Arctic Ocean coast, increasing to 20 m 100 km to the east. Hence, from Brock Island, representative of westernmost coasts, the sea l...
| Published in: | Géographie physique et Quaternaire |
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| Main Authors: | , , |
| Format: | Text |
| Language: | English |
| Published: |
Les Presses de l'Université de Montréal
1994
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| Subjects: | |
| Online Access: | http://id.erudit.org/iderudit/032973ar https://doi.org/10.7202/032973ar |
| Summary: | Emerged shorelines are few and poorly defined on Prince Patrick and Brock islands. The sparse radiocarbon dates show emergence of only 10 m through the Holocene on the Arctic Ocean coast, increasing to 20 m 100 km to the east. Hence, from Brock Island, representative of westernmost coasts, the sea level curve since the latest Pleistocene has a very low gradient, whereas on eastern Prince Patrick Island the curve takes the more typical exponential form. A decline in isobases towards the west is thus registered. Drowned estuaries, breached lakes, and coastal barriers, particularly in southwest Prince Patrick Island, suggest that the sea is now transgressing at a rate that decreases towards the north end of the island, hence there is also a component of tilt to the south. Delevelling is assumed to result from undefined ice loads, but may have a tectonic component. The sole prominent raised marine deposit is a ridge probably built in a period of more mobile sea ice, possibly at a time of stable or slightly rising sea level in the middle or early Holocene. It winds discontinuously along several hundred of kilometres of the shores of the Arctic Ocean and connecting channels, declining to the south. Les rivages émergés sont peu nombreux et mal définis dans les îles Brock et du Prince-Patrick. Les rares datations au radiocarbone n'indiquent qu'une émergence de 10 m des côtes de l'océan Arctique, au cours de l'Holocène, s'accroissant à 20 m, à 100 km vers l'est. Ainsi, à partir des côtes de l'île Brock, représentatives de la partie la plus occidentale, le niveau marin depuis le Pléistocène supérieur a un très faible gradient; par contre, dans la partie est de l'île du Prince-Patrick, la courbe du niveau marin a un caractère nettement exponentiel. On enregistre donc un abaissement des isobases vers l'ouest. Les estuaires submergés, les lacs ébréchés et les barrières littorales, surtout dans le sud-ouest de l'île du Prince-Patrick, semblent indiquer qu'il y a actuellement transgression marine à un taux qui décroît vers ... |
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