Abstract：Based on the newest gravity and aeromagnetic data in the Qiangtang Basin,this paper analyzes the gravity and magnetic characteristics of the basin,and determines basin boundaries.Furthermore,the authors research on magnetic basement structures,nature,depth variation,tectonic framework and cover thickness of the basin after compiling the magnetic basement depth map,the tectonic zoning map and the Mesozoic depth map. It is suggested by this study that the basin basement is composed of Pre-Sinian metamorphic rocks and its depth is up to 5000~15000m,and the basin cover is Mesozoic and Paleozoic.The Qiangtang Basin exhibits "two depression and one uplift" tectonic framework with the north-east depression, the southern depression and Shuanghu uplift(a magmatic complex rock uplift).The basin can be divided into 17uplifts and depressions,and its origin and development are mainly governed by the tectonics in near east-west and north-west direction.By analysis of the gravity and magnetic data, the authors refute the predecessor's view which thinks that there is an uplift belt distributed along near east-west direction(so-called central uplift belt)in the basin.By using linear inverse method in gravity spatial domain,the paper preliminarily ascertains that the thickness of Mesozoic in the Qiangtang Basin is between 4000 and 8000 m. These new understandings and conclusions introduced in the essay will provide reference for future oil and gas exploration in the basin.
熊盛青, 丁燕云, 李占奎. 西藏羌塘盆地的重磁场特征及地质意义[J]. 石油地球物理勘探, 2013, 48(6): 999-1008.
Xiong Shengqing, Ding Yanyun, Li Zhankui. Gravity and magnetic field characteristics and their geological significance in the Qiangtang Basin,China. OGP, 2013, 48(6): 999-1008.
