西藏角木日地区活动断裂及其研究意义

Active fauls in the Jiaomuri area, Xizang and their geological implications

关键词:  活动断裂  油气  角木日地区  西藏

Key words:  active fault  petroleum  Jiaomuri area  Xizang

摘要:

角木日地区位于羌塘盆地中部,构造位置处于冈瓦纳和欧亚大陆板块结合部的北缘。新生代以来,青藏高原的强烈隆升使得角木日地区新构造运动活跃,在江爱藏布、冈塘错一带发育有多条NE向和近NS向活动断裂带。这些断裂包括新近纪以来的新活动断裂,也包括一些基底老断裂的复活,其活动强烈制约了该区的地形地貌、水系格局、沉积物分布、地下热液活动和生态环境。长期以来,沿着这些活动断裂带地震活动频繁,严重影响了当地的人类生存自然地理环境。通过对区内湖泊、沼泽、温泉的水文、第四纪地质方面观察和活动构造研究,发现江爱藏布西热泉中含有较高浓度的有机质,不仅具有重要的构造意义,而且对寻找油气资源具有指示意义。

Abstract:

The Jiaomuri area in Xizang is located geographically in the central part of the Qiangtang Basin, Qinghai-Xizang Plateau and tectonically on the northern margin of the plate suture zone of the Gondwana and Eurasian continents. From the Cenozoic onwards, the intense uplifting of the Qinghai-Xizang Plateau gave rise to very active neotectonic movements in the Jiaomuri area, Xizang. Several NE- and nearly NS-trending active faults and associated frequent earthquakes, old and new, are developed in the Jangngai Zangbo and Gangtangco areas, and have important effects on the topography and geomorphology, drainage patterns, sediment distribution, underground hydrothermal activity and ecological environments. The discovery of the organic matter with higher concentrations in the hot springs in the Jangngai Zangbo area on the basis of hydrology of the lakes, swamps and hot springs, Quaternary geology and active structures in the Jiaomuri area is important not only to the tectonic aspects but also to the petroleum exploration in the study area.