A Suggestion to Improve the Chronology of Quaternary Glaciations in China
SHI Ya feng(Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou Gansu 730000, China)
Table of Chinese Quaternary Stratigraphic Correlation Remarked with Climate Change presented by 16 authors under the direction of CAS Academician Liu Dongsheng has been published for nearly two years, of which a part, entitled by Comparative Study on the Quaternary Glaciations and Maritime Isotope, was written by Shi Yafeng. In view of recent discovery, the following three points are suggested to supplement the Chronology of Quaternary Glaciations in China. (1) ESR dating demonstrates that the age of the moraine at 2 996 m a.s.l., 500 m above the present river bed, in the Zhonglianggan Mountain in the headwaters of the Bailang River on the north slope of the Qilian Mountains was 462.9 ka BP, and those of the moraines at Gaowanfeng terrace, 200～300 m above the present river bed, in the upper reaches of the Urumqi River in the Tianshan Mountains were 477.1 ka and 459.7 ka BP. These are equivalent to MIS 12, which may correspond to traditional Kansan-Mindel glacial period. The period, together with MIS 2, MIS 6 and MIS 16, belongs to the major sequence with 100 ka cycle. (2) Temperature in MIS 3b, calculated from the δ 18 O recorded in Guliya ice core, was about 5 ℃ lower than that at present. Moraine of shan Zhuang stage in Xueshan Villa in Taiwan has a TL Age of (44.25±3.72) ka BP, and moraine in the rümqi River valley at the high wang feng stage of the Tianshan Mountains has an ESR Age of 45.9 ka BP. Corresponding to this stage, the advance of glaciers in the Himalayas, the Karakorum Mountains and the southern slopes of the Hindu Kash Mountains was more evident. According to a preliminary study, in the cold MIS 3b, glaciers in 23 sites of 12 regions in Asia, Europe, North America, South America and Australia all advanced in a scale even greater than that in MIS 2. In other words, during the LGM, in MIS 3b precipitation was plenty and favourable to the extension of glaciers, although the inferred temperature reduction was less than that in MIS 2. (3) During the warm MIS 3a, not only the Tibetan Plateau had an unusual warm and humid climate, but also the whole China had rich precipitation, more than that at present in general, together with large area of transgression, with a high sea level, merely 8～10 m lower than that at present. Climate and environment in MIS 3a was virtually comparable with the interglacial period.
【Fund】： 中国科学院寒区旱区环境与工程研究所知识创新工程项目 (CACX2 0 0 2 10 2 );; 中国科学院知识创新工程重大项目 (KZCX 100 6 ;KZCX2 30 1)资助
【CateGory Index】： P534.63
【CateGory Index】： P534.63