新疆黄土分布规律及粉尘来源

通过新疆不同区域地形、黄土时空分布规律、物质组成等资料的对比，结合区域环流形势和沙尘天气的综合分析提出：不同黄土分布亚区，受不同的大气环流、局地环流和地形的作用，具有不同粉尘来源。南亚区主要来自塔克拉玛干沙漠，北亚区主要来自古尔班通古特沙漠，而形成西亚区黄土的粉尘主要来自中亚荒漠。

Spatial-Temporal Distribution of Loess and Source of Dust in Xinjiang

The loess cover of Xinjiang is one part of the loess belt in China. Based on the differences of regional landform, sedimentary feature and material components of Xinjiang loess (mineral, grain size and contents of CaCO\-3), it can be divided into three subregions, namely the Northern Subregion, Southern Subregion and Western Subregion. The results studying on local topographic condition, the regional atmospheric motion and the transportation and depositional processes of dust show that the loess in different subregions of Xinjiang has various sources. It was affected by general atmospheric circulation on several scales and related to the weather processes of dust sources.The Southern Subregion is located at the south of Tianshan Mountains. The loess cover is mainly widespread along the northern slope of Kunlun Mountains. The sediments accumulated in Tarim Basin and Taklimakan Desert supported plentiful silts for the loess formation of this subregion since 880 ka BP. In the northern part of Tianshan Mountains, namely the Northern subregion, the loess cover lies at the foot of the West Mountains and northern slope of Tianshan mountains. The dust to form the loess mainly comes from the desert of Junggar Basin. According the TL dating, the loess had been accumulated since 285 ka BP. The Western Subregion is situated at the Yili area and belongs to an intermountane basin of Tianshan Mountain. The loess distributes along the steppe and desert steppe and was mainly accumulated during the Late Pleistocene. The westerly circulation is accounted for the transportation of dust and Central Asia Deserts is the main source of loess materials of this region.