Formation and Environmental Evolution of Sand Wedges on the Tianshuihai North Lakeshore in the Western Kunlun Mountains

详细信息   

• 责任者：Chang Xiaoli(State Key Laboratory Frozen Soils Engineering ; Cold and Arid Regions Environmental and Engineering Research Institute ; Chinese Academy of Sciences ; Lanzhou 730000 ; China) ; Jin Huijun
• 刊名：Quaternary Sciences
• 出版年：2011
• 卷期：31(1)
• 关键词：晚更新世 ; Upper Pleistocene ; 古环境 ; paleoenvironment ; 昆仑山 ; Kunlun Mountains
• 页码：p.112-119
• 图表：2 illus., 5 tables, 48 refs.
• 分类号：1400
• issnNo：ISSN1001-7410
• isbnNo：CN11-2708/P

摘要

Tianshuihai, located in the Western Kunlun Mountains regions in the north-west of the Plateau, spreads widely with sand-wedges and other periglacial features. The sand-wedges, which were developed in cold climate conditions, are of important significance for paleo-climate or paleo-environment reconstruction. The grain-size distribution, ¹⁴C dating of organism and mineral composition were analyzed in the sand-wedge and the surrounding rock. The key findings are as follows: 1) the sand-wedge is mainly comprised of light minerals with debris accounting for 75%in weight; 2) the sand-wedge could be distinctively divided into three sub-parts with respect to the paper, grain-size and figure of the infill of the results of ¹⁴ C dating indicates that these three parts were formed in 11.5 ka B.P., 11.9 ka B.P.  and 13.9 ka B.P., respectively; 3) compared with the climate changing pattern derived from the ostracods research in the Sumxi Co Lake and Bangong Co Lake in the vicinity, these three sub-parts were all formed in the climate cooling period; and 4) the corresponding mean air temperatures were about 1.8 ℃, 1 ℃ and 4℃ less than present temperature in Tianshuihai region in the Western Kunlun Mountains, respectively. At last, sand-wedges could be considered as an important indicator for cold-arid climate condition and could be used to reconstruct the paleo-climate or paleo-environment.