摘要
采用粒度分析、岩石岩性分析、砾石统计等方法,本文认为新疆叶城地区第四纪粗砂砾层为冲积-洪积类型。沉积物的组分结构及其空间分布呈带状变化规律。沉积物分布受昆仑山强烈隆起的控制,反映了昆仑山隆起的时代和阶段性。
A series of Quaternary sands and gravels are well distributed on the northern foot of West Kunlun Mountains in Yecheng area oi' Xinjiang. Based upou their appearance and composition of landforms, these deposits in different ages occur in zonation. The Xiyu Conglomerate (Q. of early pleistocene, conformably contacted with the red sandstone and siltstone of pliocene at the front of the mountains, is drawn and intensively deformed with the upheaval of the Kunlun Mountains. Wusu Group (Qo), a group of grayish sand-gravels unconformably covered on the pliocene and lower pleistocene strata, extended toward the front of the mountains to form the high pluvial platfrom.The lower pluvial platforms are constructed of upper pleistocene strata which spread outside the high pluvial platforms and in the valleys outside the mountains. They have been weathered to form thesurface of conglomerate-Gobi.In addition, aeolian sandy loess spread fromthe periphery of Taglamagan Desert to the high mountains below the elevation of 4,200m asl.Valuable data obtained from the grain-size analyses and gravel statistics show that these sand-gravels deposited since early Pleistocene in this area are all generated by alluvial-pluvial forms.The genesis and distribution of these deposits is clearly correlated to the intense upheaval of Kunlun Mountains in Quaternary Period. Based upon the deformation of lower Pleistocene Series and distribution or relative height of mid-pleistocene strata, it may be concluded that the uplifting of Kunlun Mountains is continuously intensified. Aeolion sand loess spread from the desert to the slope of high mountains show that the climate tends to be drier. The environmental changes reflected by the deposits at norhern foot of West Kunlun Mountains are coincided to that of the whole Qinghai-Xizang Plateau.
出处
《地理研究》
CSSCI
CSCD
北大核心
1992年第4期57-67,共11页
Geographical Research
基金
国家自然科学基金
