Discussion on deep gravity field and Cenozoic structural system in Qinghai-Tibet plateau
Yang Hui1, Wang Yichang2
Geology Research Center. Geonhvsical Research Institute. Bureau of Oil Genohvsical Prosnectino. P.
0. Box 11-1，Zhuuzhuu City, Hebei Province. 072751，China
Abstract：Deep gravity field of Qinghai Tibet plateau consists of one gravitational high , two gravitational lows and three gravitational anomalous zones which extend to 1700km long in east west trend and exists a offset zone on south north direction along the trend, forming the pattern of which zonation is in south north direction and blocking is in east west direction. Conducting forward calculation of gravitational anomaly according to crastal depth measurement data, crastal thickness of the ragion has been obtained by using variable density inversion for gravitational anomaly of deep source. There are correlations at four different levels between gravity field and topography on platean, among which the third level has been proved by MT conductive zone inside the crust, that fully reflected a close relation between material activity of mantle in deep crust and Cenozoic structure at surface. The close relations between depth and shalow, structure and topography and geolo gy and geophysics reflect that exists a Cenozoic structural system caused by deep act on plateau. Extentional subsiding periode is E 3 E 1. N 2 Q 2 is the periode of rapid plateau uplifting and differential activity for faulted block. The paper finally points out that central faulted zone and northern fault trough like Baitan lake, Xijinwulan and Tuotuo river are favourable region for searching oil and gas.
杨辉, 王宜昌 . 试论青藏高原深部重力场与新生代构造体系[J]. 石油地球物理勘探, 2000, 35(5): 617-627.
Yang Hui ,Wang Yichang. Discussion on deep gravity field and Cenozoic structural system in Qinghai-Tibet plateau. OGP, 2000, 35(5): 617-627.
