合肥盆地和郯庐断裂带南段深部地球物理特征研究

A study on geophysical features of deep structures of the Hefei Basin and the southern Tan-Lu fault zone

根据重、磁、电、震资料联合反演和综合解释,研究了合肥盆地和郯庐断裂带南段深部结构特征和构造样式.合肥盆地呈现深部印支面以下为逆冲断层、以上为张性正断层的构造样式,盆地构造反转发生在晚侏罗世,早白垩世是裂陷盆地形成的主要时期,早白垩世晚期合肥盆地发生构造反转,发育冲逆、冲推覆构造.郯庐断裂带南段表现为“上正下逆”的构造变形样式和正花状构造特征,并经历了复杂的挤压走滑-引张正断层变形过程.

Based on detailed processing of gravity, magnetic, electricity and seismic profile data and applying synthetic geophysical inversion technique and interpretation, we study the deep structures and structural styles of the Hefei Basin and the southern Tan-Lu fault zone. In the Hefei basin, the thrust faults occurred in the strata below Indo-China movement unconformity, while rifting system developed in the upper strata over the unconformity. Tectonic reversion in the Hefei basin happened in the late Jurassic. Rifting basin was developed in the early Cretaceous, but a reversion occurred at the latest of the early Cretaceous, and leaded to thrust and nappe structures. The Tan-Lu fault zone that bounds the Heifei basin to the east displays a style of normal faulting in the shallow part and reverse faulting in the deep part, which recorded the change of tectonic regimes during the Mesozoic in East China.