Optical dating of sand wedges and ice‐wedge casts from Qinghai Lake area on the northeastern Qinghai‐ Tibetan Plateau and its palaeoenvironmental implications
Sand wedges and ice‐wedge casts in the Q inghai L ake area on the northeastern Q inghai‐ T ibetan P lateau ( QTP ) occur within alluvial gravel or river terrace deposits. In this study, we report the results of quartz Optically Stimulated Luminescence ( OSL ) dating of the infill of five relict sand...
| Published in: | Boreas |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
2012
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1111/j.1502-3885.2012.00288.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.2012.00288.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.2012.00288.x |
| Summary: | Sand wedges and ice‐wedge casts in the Q inghai L ake area on the northeastern Q inghai‐ T ibetan P lateau ( QTP ) occur within alluvial gravel or river terrace deposits. In this study, we report the results of quartz Optically Stimulated Luminescence ( OSL ) dating of the infill of five relict sand wedges and one ice‐wedge cast. Combining our dating results with previously published luminescence ages of permafrost wedges in the Q inghai L ake area, we show that sand/ice wedges formed at c. 62 ka, c. 45 ka and between 30 and 15 ka, and that the mean annual air temperature ( MAAT ) was depressed by at least ∼3° C relative to present during the sand/ice‐wedge formation periods. This new work is partially corroborated by post‐ LGM proxy records from lakes and aeolian deposits reported from the northeastern QTP . It also significantly extends the palaeoenvironmental record in the region in the period before the LGM, when other proxy records are rare, allowing a better understanding of the palaeoenvironmental conditions on the northeastern QTP . |
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