扬子地块东北缘多期叠加变形及形成演化

对扬子地块东北缘的地层序列研究进展、多期叠加变形特征等作了较系统阐明。识别出在中三叠世末至早侏罗世前,由深层滑脱折离剪切形成的区域性NW-NWW向,向西倒覆褶皱,并被随后的主期变形所叠加,形成一系列以NE向为主,在早期褶皱正常翼上为背、向斜,在倒转翼上为背形向斜、向形背斜褶皱带。晚侏罗世到早白垩世间形成滑覆逆冲构造,并随着北侧的大别山地,南部的皖南山地急剧抬升,在安徽宣州市北至贵池市南,形成由山地向盆地中心,因重力相向滑覆冲断形成的对冲带。在重新认识区内构造演化的基础上,对动力学作了初步分析。

MULTI-SUPERIMPOSED DEFORMATIONS AND THEIR EVOLUTION IN NORTHEASTERN MARGIN OF YANGTZE BLOCK

Multi superimposed deformations have systematically been discussed based on the advance of stratigraphic sequences in the northeastern margin of the Yangtze block. The new stage deformation of them was formed before middle Triassic and end of early Jurassic, there was a regional folding formed by depth detachment shearing striking NW WNW, dipping to the east or fall down to the west. They were superimposed by the main stage folding and formed a series of folds striking NE. So you can find the normal folds in the normal rims, while overturn folds in the overturn rim of first folds. The detachment or thrust occurred between later Jurassic to early Cretaceous. Due to the uplifting of Dabie Mts. and Wannan Mts. on the north and south sides, the double thrusts belt formed by gravity flown from the maintains to the center of basin along the north side of Xuanzhou and south side of Guichi. The geodynamics of the deformations has been discussed based on the newly recognized structural evolution.