PRELIMINARY GEODYNAMIC MODEL OF GOLMUD PIIN QI GEOSCIENCE TRANSECT ─EJIN QI GEOSCIENCE TRANSECT
GAO RUI; CHENG XIANG-ZHOU(Lithosphere Research Center, Chinese Academy of Geological Sciences, Beijing 100037)DING QIAN(Aero-Geophysical and Remote Sensing Centre, MGMR, Beijing 100083)
The Golmud─Ejin Qi Geoscience Transect (GET) is located in the northwestern part of China. It starts from the northern margin of the Kunlun Mts., and crosses northerly the Qaidam Basin, Har Lake, Qilian Mis., Hexi Corridor and Beishan, and ends in Ejin Qi near the Sino─Mongolian border. The transect is about 900 km long in all.The article describes the tectonic framework, gives a omprehensive analysis of geophysical field survey data and a preliminary geodynamic model of the geoscience transect from Golmud to Ejin Qi.The model expresses the mechanical state of double compression that consists of the major northward compression of the indian plate and the minor southward compression of the Siberian Plate. The convergent force of the plates results from the uneven flows in the mantle. The compression occurs mainly in the middle and lower crust,in the upper crust thrusting and strike-slipping followed by extension are dominant. These constitute the mechanical system of the newest deformation of the lithosphere.