金湖凹陷构造特征研究

金湖凹陷位于苏北盆地西部，是呈北东向长务状展布的中新生代断陷一坳陷型盆地。在郯庐断裂构造活动影响下先后经过多次应力作用，断裂系统复杂，构造十分破碎。利用连片三维地震资料开展了大量的综合解释研究，通过对金湖凹陷构造几何形态、形成演化及其控制机理进行分析认为：金湖凹陷第三系的构造活动主要分为吴堡运动期和三垛期，吴堡期的地质运动主要表现为地层的抬升与沉降，应力以拉张为主；三垛期苏北盆地受郯庐断裂带的右行走滑作用影响明显增强，应力场开始复杂化，剪切、挤压和拉张都有发生，使得金湖凹陷发生了剧烈的后期地质改造，并形成了以伸展构造为主，走滑构造、挤压构造和反转构造共存的构造特征。

Study on structural feature in Jinhu Sag

Jinhu Sag is a Mesozoic-Cenozoic rifted and depressed basin, which lies in the west of the Subei Basin, and has a long narrow shape with the NE trending. Influenced by tectonic activities of Tanlu Fault, Jinhu Sag experienced multiple effects of stress, which induced to complex fault system and broken structure in Jinhu Sag. Based on lots of study on integrated interpretation utilizing concatenating 3D seismic data and the analysis on structural feature, structural evolution and its controlling mechanism in Jinhu Sag, it is considered that the tertiary structural activities in Jinhu Sag can be divided into two stages, including Wubao period and Sanduo period. In Wubao period the geologic movement was characterized by stratum uplifting and subsidence, the main stress was extension. While in Sanduo period, influenced by right-lateral strike-slip motion of Tanlu Fault, the stress field became complex in North Jiangsu Basin, stresses of shear, extrusion and became complex in North Jiangsu Basin, stresses of shear, extrusion and extension were all appeared, which result in violent geological modification in late period in Jinhu Sag, and the structure was characterized mainly by extensional structures companied with strike-slip structures compressive structures and inversion structures.