长江源区新构造运动及其生态环境效应

基于长江源区生态环境地质调查的大量实际资料及调查成果，经分析研究发现，长江源区早更新世处于走滑拉分运动的大陆动力学背景，在整体隆升中，形成走滑拉分盆地且分割盆地的断块山、湖泊广布；中更新世反转为挤压隆升，在整体抬升中迎来了新构造期最大冰期，湖泊萎缩；晚更新世－全新世过渡为整体走滑-挤压收缩，经历了动荡的隆升过程，湖泊响应明显。近代，特别是20世纪70年代以来，新构造活化与寒冻风化岩屑坡扩大、沙漠化蔓延、湖泊与沼泽湿地萎缩、区域地下水位下降、生态环境日益恶化等关系密切。因此，新构造驱动在长江源区生态环境恶化中起主导作用，而其他因素则起到促进与加速作用。

NEW TECTONIC MOVEMENT AND ITS ECOLOGICAL ENVIRONMENT INFLUENCES IN YANGTZE RIVER SOURCE AREA

Based on the data and surveyed results of geologic and ecological environment in Yangtze River source area, it is found that there was continental dynamics background of strike-slip movement in Early Pleistocene Epoch and formed strike-slip-extensional basins, faults and lakes in the massive arched movement; it began to compress-arch movement in Middle Pleistocene Epoch, that was the great glacial epoch in new tectonic movement period , the lakes became smaller and smaller; it began to strike-slip and compressed movement in Late Pleistocene Epoch-Holocene in this area. Especially in twenty century seventies, it was closed relation- ships among neotectonics, weathering, desertification, changes of lakes and marsh areas, drop of water level and ecological environment worse and worse. So, the neotectonics played the main function in the ecological environment changes, and the other factors played supplementary functions.