CHARACTERISTICS OF THE RECENT TECTONIC DEFORMATIONS OF CHINA AND ITS VICINITY
Huan Wen-lin Shi Zhen-liang Yan Jia-quan Wang Su-yun (Institute of Geophysics State Seismological Bureau)
In this paper, regional characteristics of recent tectonic deformations in China and its vicinity are discussed. The work is based on a great amount of data of the fault plane solutions of shallow earthquakes, field seismo-geological surveys and of the Landsat imageries and some other geophysical observations. The results of the analysis, show that in eastern China, a predominat feature of recent tectonic deformation appears to be shear fractures, consisting of dextral strike-slip faulting with directions from NNE to NE. There are also a few conjugating strike-slip sinistral faults with directions from NWW to NW. In western China, recent tectonic deformations are characterized by compressions of which the most outstanding features are the four successive arcuated tectonic belts convex to the northeast of the Qinghai-Xizang (Tibet) Plateau. The first arcuated tectonic belt and the northeastern part of the fourth belt are mainly thrusting due to compression. The second and third arcuated tectonic belts are dominated by strike-slip faults due to lateral compression. Regional characteristics of the recent tectonic deformations are also reflected by the regional distributions of crustal thickness. Recent tectonic deformations of China and its vicinity are closely related to the movements of the surrounding tectonic plates.