Multiple deglaciations of the Hudson Bay Lowlands, Canada, since deposition ot the Missinaibi (Last-Interglacial?) Formation

Auteurs :
ANDREWS, J. T.
SHILTS, W. W.
MILLER, G. M.

Description :
Isoleucine epimerization ratios of in situ and transported shells recovered from till and associated marine and fluvial sediments cluster into at least 4 discrete groups. Two alternative explanations of the data are offered, of which we strongly favor the first: Setting the age of the last interglacial marine incursion, the Bell Sea, at 130,000 yr B.P. results in a long-term average diagenetic temperature for the lowlands of + 0.6 C. Using this temperature enables us to predict the age of shells intermediate in age between the last interglaciation and the incursion of the Tyrrell Sea 8000 yr ago. Between these two interglacial marine inundations, Hudson Bay is predicted to have been free of ice along its southern shore about 35,000, 75,000, and 105,000 yr ago. These results suggest (1) that traditional concepts of ice-sheet build-up and decay must be reexamined| (2) that high sea levels may have occurred during the Wisconsin Glaciation| and (3) that a critical reappraisal is required of the open ocean O record as a simple indicator of global ice volume.


Type de document :
Article de périodique

Source :
Quaternary research New York, 1983, vol. 19, n°. 1, p. 18-37, Références bibliographiques : 69 réf.

Date :
1983