青藏高原东部黄土沉积的基本特征及其环境  

LOESS DEPOSIT IN EASTERN PART OF QINGHAI XIZANG PLATEAU: ITS CHARACTERISTICS AND ENVIRONMENT

作　　者：王建民[1] 潘保田[1] 

机构地区：[1]兰州大学地理科学系

出　　处：《中国沙漠》1997年第4期395-402,共8页Journal of Desert Research

摘　　要：青藏高原东部黄土沉积分布广泛。本文对青藏高原东部较大范围内黄土沉积从地层学、年代学和沉积学等方面做了初步研究。结果表明：高原黄土属典型的风成沉积，其物质主要来源于高原本身，高原冬季风是粉尘搬运的动力。研究区黄土沉积虽始于中更新世，但目前分布最广泛的黄土沉积主要是末次间冰期以来的产物。高原黄土沉积地层的黄土－古土壤序列中蕴藏着丰富的环境变化信息，是研究高原季风演化的良好地质记录。中更新世以来，末次间冰期以前，研究区经历了１１次高原冬季风强盛和１１次高原夏季风占优势的时段；末次间冰期以来。Loess deposit is widespreaded in eastern part of Qinghai Xizang plateau. Preliminary studies on loess stratigraphy, chronology, sedimentology and geochemistry show that loess in the plateau is eolian in origin, and loess material is from various kinds of deposits formed mainly in the western part of the plateau and the plateau monsoon is responsible for transportation and deposition of the loess dust. Although loess deposition started as early as in the Middle Pleistocene, most of the loess deposit in the eastern part of the plateau was deposited since the last interglacial. Our study also shows that loess paleosol sequence is one of the best sources from which the history of the plateau monsoon evolution can be derived. Loess stratigraphy shows that there are 11 enhanced summer monsoon events and 11 intensified winter monsoon events before the last interglacial, and the last interglacial glacial cycle also experienced drastic environment change which correlated well with other climate records in the area.

关 键 词：青藏高原 黄土沉积 环境演化 季风 古环境 

分 类 号：P531[天文地球—古生物学与地层学] P512.2[天文地球—地质学]