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中国西北地区晚更新世湖泊演变和水文循环是第四纪科学研究的热点,但近年来随着研究的深入而存在一些争论,其焦点之一就是晚更新世高湖面形成的时代.通过对阿拉善高原的野外考察、岸堤测量及14C定年,在该区域晚更新世高湖面与大湖期的研究上,不仅获得了更多的地貌学、沉积学证据,而且对高湖面的形成时期有了新的认识,为开展干旱区水循环与水资源演变研究提供了基础资料.考察发现,居延海地区至少存在10道不同海拔高度的砂砾质岸堤,吉兰泰盐湖西北岸发现至少存在4道古湖岸堤,猪野泽东北岸存在9道砂砾质岸堤和一级湖成阶地.对上述古湖岸堤中遗存的瓣鳃类、腹足类生物壳体等14C测年结果及雅布赖盐湖地层年代进行分析,确证MIS3阶段阿拉善高原存在最大高湖面.现有的OSL年代数据虽然与已报道的14C年代及本研究的14C年代结果存在较大分歧,甚至有些OSL年代结果不支持MIS3阶段存在高湖面,但不足以否定MIS3阶段存在高湖面的基本结论.这两种测年结果的差异很可能指示了两个不同时期在同一区域均存在高湖面,也暗示了阿拉善高原可能在MIS5阶段和MIS3阶段早期均存在高湖面.
Late Pleistocene lake evolution and hydrological cycle in Northwest China are the hotspots of Quaternary scientific research, but with the deepening of research in recent years, there are some controversies, one of the focuses of which is the formation of the Upper Pleistocene epoch.Through the analysis of Alla In the field investigation, bank survey and 14C dating of the good plateau, more studies of geomorphology and sedimentology have been obtained on the study of the Upper Pleistocene lakes and the Great Lakes in this region, and the formation of high lakes New understandings provide the basic data for carrying out the research on water cycle and water resources evolution in arid areas.It is found that there are at least 10 gravel bank dike at different altitudes in Juyanhai area and at least 4 There are 9 gravel banks and a first-grade lake in the northeastern shore of the Nomaze Zecai, and the 14C dating results such as the relict gills and gastropod shell in the above-mentioned ancient bank dike, Stratigraphic analysis to confirm the existence of the largest high lake in the Alashan Plateau during MIS 3. Although the existing OSL data are quite different from those reported in the 14C and 14C of this study Some OSL results do not support the existence of high lakes in MIS3 but not enough to negate the basic conclusion that there is a high lakes in MIS 3. The difference between these two dating results probably indicates that there are high lakes in the same area in two different periods It is suggested that there may be high lakes in the Alashan Plateau both in MIS5 and early MIS3 phases.