摘要
对位于青藏高原东北缘的青海省民和黄土采样和粒度分析结果的研究表明 ,民和黄土的粒度远大于兰州等地黄土的粒度。民和黄土 (粒径 >3 0 μm和 >5 0 μm的粗颗粒组分 )分别指示了冬季风强度变化和青藏高原阶段性隆升所激发产生的黄土物源区作用。高原表面的寒冻风化物和冰碛物等给民和黄土提供了可观的粗物质补给。
The sample collecting and grading analysis of Minhe loess in Qinghai Province,located in the northeast fringe of Qinghai-Tibet Plateau,indicates that the grains size of Minhe loess is coarser than that of other regions such as Lanzhou.The >30 μm and >50 μm coarse grains respectively denote intensity change of winter monsoon and the role of loess source area stimulated by the uplift of Qinghai-Tibet Plateau.The surface of plateau supplies abundant coarse matters for Minhe loess with cold weathering material and glacial till.It is the uplift of plateau and other regional tectonic movement that leads to the diversification of the source area of loess.This mainly explains the difference of grain sizes in the loess that plateau uplifting and intensity change of winter monsoon induced by the uplift of plateau,and regional tectonic movement and the difference in configuration of topography,of the interaction between plateau monsoon and ambient flow,as well as the difference in source area of loess and the variation in the range of the source area.
出处
《地质科技情报》
CAS
CSCD
北大核心
2002年第2期41-44,共4页
Geological Science and Technology Information
基金
国家自然科学基金资助项目 (4 9972 0 5 7)
原地矿部项目"甘肃兰州红古城
新寺乡 1: 5万区域地质调查"
