北京大学学报(自然科学版)

塔北隆起中西部新近纪末构造应力场数值模拟

王延欣,侯贵廷,李江海,潘懋   

  1. 北京大学地球与空间科学学院,造山带与地壳演化教育部重点实验室,北京100871;
  • 收稿日期:2007-11-06 出版日期:2008-11-20 发布日期:2008-11-20

Numercial Simulation of Tenconic Stress Field at the end of Neocene in the Midwest of Tabei Uplift

WANG Yanxin, HOU Guiting,LI Jianghai,PAN Mao   

  1. The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871;
  • Received:2007-11-06 Online:2008-11-20 Published:2008-11-20

摘要: 根据油田地震资料解释和构造分析,建立了新近纪末塔北隆起中西部平面与剖面地质模型,通过线弹性有限元方法的计算,得出该地区应力场模拟结果。构造应力场模拟结果表明,区域性南北向挤压应力控制了整个塔北隆起中西部新近纪末的构造应力场;研究区内牙哈断裂、轮台断裂、红旗断裂、英买7断裂在新近纪末为压扭性断裂,并具有左行走滑分量,喀拉玉尔滚断裂为右行走滑断裂,羊塔克断裂为纯压性逆冲构造;在区域挤压应力作用下,受主干断裂影响形成的局部构造应力场控制了局部次级构造类型的产生;从剖面应力场模拟结果来看,最大主应力方向在中央断隆区由水平变为倾斜,垂向应力分量变大,是导致压拱构造形成的主要因素。

关键词: 数值模拟, 构造应力场, 断裂构造, 塔北隆起中西部

Abstract: The plane and profile geological models at the end of Neocene in the midwest of Tabei uplift are established on the basis of seismic data of oil field and tectonic analysis, and the numerical simulation results of tectonic stress field in the area are obtained using linear elastic finite element method. Modeling results indicate that N-S regional compressive stress dominates the stress field of the whole area at that time, as well as that all faults of Yaha, Luntai, Hongqi, Yingmai 7 are compresso-shear structures with sinistral strike slip, while Kalayuergun fault is right lateral, and Yangtake fault is pure compressive thrust. In the condition of regional compressive stress, local stress field is formed, and affected by the main faults, which controlles the generation of secondary structures. In the modeling results of profile stress field, the orientation of the major principal stress change from horizon to incline in the middle of the uplifting area and the vertical stress component becomes bigger, which is the main factor to control the development of the compressional and subtuberant structures.

Key words: numerical simulation, tectonic stress field, fault structure, the midwest of Tabei uplift

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