青海可可西里地质遗迹及其构造演化

Geological heritage of Hoh Xil in Qinghai and its tectonic evolution

青海可可西里自石炭纪以来经历了复杂的构造演化和地表过程,形成了集高山、宽谷、夷平面、冰川、热泉、河流和湖泊等地貌元素为一体的高原高寒地貌,同时还包括了蛇绿混杂岩带、活动断裂带、地震遗迹和火山遗迹等地质元素。在调研前人研究资料和实地野外考察基础之上,根据IUCN(2005)提出的13类地质主题分类标准将区内的地质遗迹分为地质构造、火山和地热遗迹、山脉、地层剖面、河流和湖泊、现代冰川、冰期遗迹7类,共计60余处地质遗迹点。可可西里地质遗迹对重建古特提斯构造域、研究天然地震机制、青藏高原北部隆升过程及全球气候变化均具有重要的意义。基于可可西里区内地质遗迹和前人资料恢复出可可西里石炭纪以来经历了8个构造演化阶段。

Hoh Xil in Qinghai has undergone complicated tectonic evolution and surface process since Carboniferous. Someplateau and alpine landforms were formed by these geological processes, such as high mountains, broad valleys, planation surfaces,glaciers, hot springs, rivers and lakes. In addition, Hoh Xil has preserved some geological heritages, like ophiolitic mélange zone,fault zones, earthquake sites and volcanoes. In this paper, the authors divided geological heritages of Hoh Xil in Qinghai into seventypes, i.e., geological structure, volcanic systems, mountains systems, stratigraphic sites, fluvial and lacustrine systems, glaciers, andice ages site, which constitute more than sixty sites of geological heritages in accordance with IUCN (2005), based on geologicalfield survey and previous studies. The results show that the study of geological heritages in Hoh Xil of Qinghai has importantgeoscience significance in reconstructing ancient Tethys and investigating the mechanism of earthquake, the uplift process of the Tibetan Plateau and the relevant global climate change. Eight tectonic evolution stages of Hoh Xil from Carboniferous to Quaternarywere recognized on the basis of geological heritages in Hoh Xil area.