CHARACTERS OF TECTONIC EVOLUTION OF THE JIYANG DEPRESSION
WANG Ying, ZHAO Xi kui, GAO Bo yu (Chengdu University of Technology, China)
The formation and evolution of a basin is correlated with the movement of plates. So the authors consider that the formation and evolution of the Chinese inland basins are the necessary result of plate movements since Paleozoic. The Huabei plate solidified after the Fuping movement. The Luliang movement ended the formation of Huabei plate and formed th old uniform and steady Chinese Plate. The Jiyang depression is one part of the Bohai Bay basin. One must know the formation of the Bohai Bay basin if one wants to learn the character of Jiyang depression's tectonic evolution. The Jiyang depression has different characters in different times. In Paleozoic, the Huabei plate was mostly the rising motion and the descending motion, but, because its north edge was in the state of activity and its southeast undergone many times of tectonic evolution, the movement brought about the slight distortion of the Huabei inner crust. In Mesozoic, the Tanlu fracture and Luxi heave played an important role in the evolution procession of the Jiyang depression. In this time, the Jiyang depression formed its basal ambit. In Cenozoic, the Jiyang depression was in the phase of strongly tectonic movement and formed the block frame. Then, after the undulate movement of the earth mantle, it became the fault depression basin which has four sags and six lobes now.