Marie-Luce CHEVALIER
1 Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, CAGS, Beijing 100037, China 2 Jiangsu Donghai Crustal Activity in Deep Holes of the Continental Scientific Drilling National Observation and Research Station, Lianyungang, Jiangsu 222300, China 3 Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, ChinaWANG Shiguang
4 National Institute of Natural Hazards, MEMC, Beijing 100037, ChinaAnne REPLUMAZ
5 ISTerre, Université Grenoble Alpes, CNRS, Grenoble 38610, FranceLI Haibing
1 Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, CAGS, Beijing 100037, China 2 Jiangsu Donghai Crustal Activity in Deep Holes of the Continental Scientific Drilling National Observation and Research Station, Lianyungang, Jiangsu 222300, China 3 Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, ChinaThis project was financially supported by the Second Tibetan Plateau Scientific Expedition of the Ministry of Science and Technology of China (Grant No. 2019QZKK0901), the National Natural Science Foundation of China (Grant Nos. 42020104007, 41941016), the China Geological Survey (Grant No. DD20221630).
Numerous studies dated glacial deposits within the Himalayan-Tibetan orogen. While most focus on young deposits, i.e., younger than the Last Glacial Maximum (LGM or Marine oxygen Isotope Stage (MIS)-2, ~20 ka), older moraines such as those from MIS-6 (~130–191 ka) are much harder to date and interpret due to the less well-preserved nature of their surfaces and boulders, as well as their scattered and continuous age distribution due to long-lived erosion since deposition. Here, we dated with 10Be, two imbricated moraines near Yadong in southern Tibet, as MIS-2 and 6, showing that the most extensive, smooth surfaces were abandoned during MIS-6. Compiling published data from 54 MIS-6 moraines on the Tibetan Plateau reveals that they exist in most regions, dry or humid. They are particularly well-preserved (sharp crests) in eastern and northern Tibet, while in southern and central Tibet, their crests are rounded to sub-rounded. Because both MIS-2 and 6 were equally cold, and because MIS-6 moraines are much more extensive than those from the LGM, we conclude that MIS-6 glacial advances were controlled by more abundant precipitation than during MIS-2. This would be consistent with the peak in Asian monsoon during MIS-6, revealed by sediments from the South China Sea.
Marie-Luce CHEVALIER, WANG Shiguang, Anne REPLUMAZ, LI Haibing.2022. Marine Oxygen Isotope Stage (MIS)-6 Glacial Advances on the Tibetan Plateau More Extensive than during MIS-2 due to More Abundant Precipitation[J]. Acta Geologica Sinica(),96(5):1484-1494
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