Very large cryoturbation structures of Last Permafrost Maximum age at the foot of the Qilian Mountains (NE Tibet Plateau, China)
Unusually large cryoturbation structures (4-4.5 m amplitude), developed in channel gravels and overbank fine-grained deposits of a river terrace on the NE Tibet Plateau, China, were formed by loadcasting as late Pleistocene-age permafrost degraded. It is suggested that the oversaturation and liquefa...
| Published in: | Permafrost and Periglacial Processes |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2016
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| Subjects: | |
| Online Access: | https://research.vu.nl/en/publications/c608e192-4971-450a-8b4f-3cfd76f2afb8 https://doi.org/10.1002/ppp.1847 http://hdl.handle.net/1871.1/c608e192-4971-450a-8b4f-3cfd76f2afb8 |
| Summary: | Unusually large cryoturbation structures (4-4.5 m amplitude), developed in channel gravels and overbank fine-grained deposits of a river terrace on the NE Tibet Plateau, China, were formed by loadcasting as late Pleistocene-age permafrost degraded. It is suggested that the oversaturation and liquefaction of the thawed sediments could have been achieved only if the amount of ice in the upper 4-4.5 m of terrace sediments had been very high. The structures, dated at around 26-20 ka by OSL, point to the presence of a massive icy layer existing within a permafrost body during the Last Permafrost Maximum. |
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