摘要本文从重力异常角度对中国大陆区域地质构造的深部结构进行了研究。基于卫星重力大数据,利用改进后的位场分离方法获取了从地表到上地幔顶部不同深度的重力异常场。分析了各个碰撞一俯冲带、造山带及盆地等地区上地幔顶部(参考深度约为72—76km)和中地壳(参考深度约为12—16km)深度的异常特征。结合地质构造、地球化学和地球物理学证据,重点讨论了重力异常产生的原因及其与中国大陆主要构造之间的关系,获得了中国大陆在环太平洋动力学体系和特提斯动力学体系这两大动力作用下不同地区差异性的壳幔响应。
This paper studies the regional geological deep structure of mainland China from the perspective of gravity anomaly. Based on the satellite gravity big data, the improved field separation method is utilized to obtain the anomalous field of different depths from the surface to the top of the upper mantle. Anomaly features of the middle crustal depths (reference depth about 12 - 16 km) and the upper mantle (reference depth about 72 - 76 km) are discussed in each collision-subduction zones, orogenic belts and basins. Combined with geological structure, geochemistry and geophysical evidences, the causes of gravity anomalies and its relationship with the main geological structure of mainland China have been analyzed and discussed. Diverse crust-mantle responses in different regions of the Chinese mainland, under the two major driving forces of the central Pacific dynamic system and the Tetbys dynamical system, were obtained.