THE STRUCTURE AND DYNAMICS OF THE CONTINENTAL LITHOSPHERE IN NORTH AND NORTHEAST CHINA PETROLIFEROUS REGIONS

The continental lithosphere of north and northeast China exhibits many Meso-Cenozoic graben systems and basins. Among them the Songliao Basin and North China Plain are the largest. These are subtle indicators of the structure and dynamics of the lithosphere. The regional geology coupled with geophysics indicates that the location and extent of these basins coincide with areas in which the lithosphere is stretched, thinnered, highly fractured and in which the geothermal gradient and heat flow are increased. However the attenuation of the lithosphere was not solely due to shallow crust normal faulting. The formation of these large basin structures are connected with deep seated processes in the mantle. It is suggested that the fundamental controlling factor was the upward advection of the asthenosphere, which may be related to the large subcontinental convection induced by the subduction of Kula-Pacific Plates under the Japan islands since late Mesozoic.