Open AccessOptical dating of sand wedges and ice‐wedge casts from Q inghai L ake area on the northeastern Q inghai‐ T ibetan P lateau and its palaeoenvironmental implications
Author(s) -
Liu XiangJun,
Lai ZhongPing
Publication year - 2013
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/j.1502-3885.2012.00288.x
Subject(s) - geology , ice wedge , quartz , permafrost , optically stimulated luminescence , geomorphology , thermoluminescence dating , geochemistry , alluvial fan , aeolian processes , physical geography , mineralogy , paleontology , sedimentary rock , oceanography , geography
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 .