豫西黄土中砂粒含量及其环境意义

研究表明,豫西黄土中含有大量的砂粒组分(> 63 μm),地域特定的地貌造成三门峡、扣马黄土中砂粒含量的增加。扣马剖面记录了自1.2 Ma来砂粒百分含量的变化过程,在我国气候逐步恶化的总体环境下,区域地貌的改变叠加在全球变化之上。随着黄河的下切,大量松散堆积物暴露于大气环境中,为冬季风提供了丰富粉尘物源,汾渭盆地、三门峡盆地、黄河两岸滩地、沙滩以及两岸山地是豫西黄土砂粒的主要源区之一。

Sand Content in Loess and Its Environmental Effect in Western Henan Province

The loess in Western Henan Province contains abundant of sand (63 μm), which is caused by the special relief in the region. The Kouma loess section has recorded the change of sand content since 1.2 Ma BP. Global climatic change is the main factor for the temporal and spatial variation of the sand content. The relief change superimposes on the global change. With the downcutting of the Yellow River, a great deal of loose sediments are exposed to the air, which provide abundant of dust for the Asia Winter Monsoon. The Fenwei Basin, Sanmenxia Basin, the bottomland and sand beach of the Yellow River, and the mountains along the Yellow River are the main source zones of sand in loess in Western Henan Province.