Geological framework of Cuoqin-Dongcuo gravity-magnetism profile in Cuoqin basin, western Tibet, China.

To investigate the geological framework in Cuoqin-Dongcuo, Tibet, we analyze, process, curve-fit and interpret the gravity-magnetism profile data collected in 2006 at 1∶50000 scale. The results show that the basement of Gangdise foundation strike-slip upwarping zone at the south of the profile is less than 1km deep with Mesozoic lost; the basement of Cuoqin basin at the middle is quite deep, deep at north and shallow at south, of which the deepest area can be up to 9km,and the basin is mainly filled with thick Mesozoic; at the north, the basement of Bangong Lake-Nujiang River suture is less deeper than 3km and that of Qiangtang terrain is about 3.5km deep. Cuoqin basin and Bangong Lake-Nujiang River suture at the middle have weak magnetic basement, while that at the northern and southern part is pretty strong.12 faults are deduced, among which,F7 is northern boundary of the basin and the southern boundary is fault F1. 6 granide bodies,2 ophiolite bodies and a volcanic layer are identified and their underground feature are represented.