上海地区地质构造特征

上海地处扬子准地台的东北端。前晋宁旋回和晋宁旋回属地槽发展阶段,由变质岩系组成地台的褶皱基底。加里东旋回为准地台发展阶段,构造层发育齐全,为海相、浅海相连续沉积。印支运动结束了本区长期海侵的历史,开创了滨太平洋大陆边缘活动的新纪元。燕山旋回构造变动、岩浆活动十分活跃。喜马拉雅旋回地壳振荡运动频繁。

THE CHARACTERISTIC OF GEOLOGIC STRUCTURE IN SHANGHAI

Shanghai is at Abstract the northeastern end of the Yangtze paraplatform. The pre-Jinning cycle belongs to the stage of geosyncline development. The folded basement of the platform in this area is composed of metamorphic lock series. The Caledonian cycle belongs to the stage of paraplatform development. Its tectonic layer has developed completely, represented by marine and shallow marine continuous sedi- ments. The Indosinian movement ended the history of long-continued transgression in the area, and ushered in a new era of the Peri-Pacific continental-margin activity. The Yanshanian cycle witnessed very active structural disturbances and magmatic activity. In the Himalayan cycle, oscillatory movement occurred frequently.