下扬子区新生代构造变形物理模拟及其主控因素

Physical simulation of Cenozoic tectonic deformation in the Lower Yangtze region and its main controlling factors

徐楠 徐曦 周波 梅甫定 高顺莉 王兴建

Xu Nan Xu Xi Zhou Bo Mei Fuding Gao Shunli Wang Xingjian

中国地质大学(武汉), 武汉 430074 2. 中国国土资源航空物探遥感中心, 北京 100083 3. 同济大学 海洋与地球科学学院, 上海 200092 4. 中海石油(中国)有限公司 上海分公司, 上海 200030 5. 成都理工大学 油气藏地质及开发工程国家重点实验室, 成都 610059

China University of Geosciences, Wuhan, Hubei 430074, China 2. China Aero Geophysical survey and Remote Sensing Center for Land and Resources, Beijing 100083, China 3. School of Ocean and Earth Science, Tongji University, Shanghai 200092, China 4. Shanghai Branch of CNOOC China Ltd, Shanghai 200030, China 5. State Key Laboratory of Oil and Gas Reservoir Geology and Exploration, Chengdu University of Technology, Chengdu, Sichuan 610059, China

下扬子新生代构造变形是中国东部新生代构造研究的重要窗口。为研究其变形机制，基于构造物理模拟，对4个主控因素进行评价与研究。设计对比实验，分析了在不同主控因素的作用下，下扬子区新生代构造的变形过程。应力与模型边界的角度和施加应力的边界位置是下扬子新生代构造变形的最优主控因素。在东侧全段挤压和东侧北段挤压的对比实验中，郯庐断裂带与下扬子及其周缘块体的构造变形均呈现显著变化；在块体厚度的对比实验中，变形与变位状态近似相同，但隆升特征存在显著差别，东西两侧边界挤压效果具有显著差异；与此同时，施加应力与模型边界角度越小，郯庐断裂带呈现右行走滑特征越明显。在最优主控因素模型中，下扬子块体新生代区域伸展构造变形与郯庐断裂带右旋走滑共同构成了一个“右旋侧向扩展变形”构造系统。

The Cenozoic extensional tectonic deformation is an important window for the study of Cenozoic tectonic dynamics in East China. We evaluated four main controlling factors and designed seven sets of physical simulations to study the deformation mechanism of the Cenozoic structure in the Lower Yangtze region. The deformation process of the Lower Yangtze region during Cenozoic was simulated with different controlling factors. Stress angle and boundary position are the main factors controlling tectonic deformation. In the paralleled-experiments, the tectonic deformation of the Tan-Lu fault and the Lower Yangtze region and its surrounding blocks showed significant variations in boundary compression. In the paralleled-experiments of block thickness, deformation and displacement were similar, but there are significant differences in uplift characteristics and extrusion effects between east and west boundaries. With smaller angle between stress and model boundary, the Tan-Lu fault presented obvious dextral movement. In the simulation with optimal controlling factors, the extensional tectonics of the Lower Yangtze block and the dextral movement of the Tan-Lu fault formed a tectonic system with dextral strike-slip and lateral extension.

中国石化科技部项目“伏龙泉断陷构造—沉积特征与油气成藏条件分析”（P15116）资助。

https://doi.org/10.11781/sysydz201703409