郯庐断裂带南段及邻区中、新生代盆地的反转机制

Inversion mechanism of Meso-Cenozoic basins of southern Tan-Lu fault and its adjacent areas

郯庐断裂带南段及邻区中、新生代盆地的反转构造主要包括盆地边缘的逆掩断层、盆地旁侧的碎裂岩带、盆地内部的楔形冲断体以及地层褶皱和底部砾岩被掩盖。靠近郯庐断裂带西侧的反转构造 ,主要受郯庐断裂带的控制 ,多为在该断裂基础上发育的斜向逆冲断层。郯庐断裂带东侧盆地 ,以 NE向线状排列为主要特征 ,它们斜交郯庐中断裂带。这些盆地的北缘被由 N→ S逆掩的隆升地块所掩盖。研究区盆地反转构造开始于老第三纪的早期 ,中、晚期为反转构造活动的强盛时期。太平洋板块相对于欧亚大陆的俯冲 ,使得大型的晚白垩世盆地解体 ,形成线状楔形冲断块和线形盆地相间排列的构造结局。同时 ,第三系在其山前堆积而成。

In Meso-Cenozoic basins of southern Tan-Lu fault zone and adjacent areas, the inverted structures include five main types-the over-thrust in the edge of the basins,the cataclasite zone on the adjacent areas of the basins, the over-thrust blocks in the basins, the fold and the lost ground layer. The inverted structures were formed along the early Tan-Lu fault in the NNE strike, and showed over-thrusting. On the east of Tan-Lu fault, the inverted structures are the over-thrusts of the north side of linear basins in the NE strike, and they intersect Tan-Lu fault. The over-thrust blocks covered Meso-Cenozoic basins with over-thrusts in NNW→SSE.The inverted structures in these basins were formed at early Eogene. Middle-late Eogene is a period of strong movement. The movement of Pacific plate in SE→NW direction split a big late-Cretaceous blocks group in the NE strike,and Eogene basins were formed in frontal basins.