Evidence from thermoluminescence dating for Middle Wisconsinan deglaciation in the Hudson Bay Lowland of Manitoba
We report here the first direct dating of the nonglacial, intertill Nelson River sediments from five sites in northern Manitoba. We used the thermoluminescence (TL) sediment-dating technique to obtain age estimates of 32–46 ka for four samples and 119 ka for the fifth, all samples previously correla...
| Published in: | Canadian Journal of Earth Sciences |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1991
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/e91-023 http://www.nrcresearchpress.com/doi/pdf/10.1139/e91-023 |
| Summary: | We report here the first direct dating of the nonglacial, intertill Nelson River sediments from five sites in northern Manitoba. We used the thermoluminescence (TL) sediment-dating technique to obtain age estimates of 32–46 ka for four samples and 119 ka for the fifth, all samples previously correlated to the Sangamonian Stage (80–130 ka) Missinaibi Formation. We interpret the younger TL dates as being within 20–40% of the true deposition ages, but interpret the oldest TL date as an overestimate because of ineffective zeroing of the light-sensitive TL associated with observed pebble and sand detritus in that sample. Thus these younger direct dates imply a significant climatic warming and deglaciation in the heart of the Laurentide Ice Sheet area during Middle Wisconsinan time. |
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