柴达木盆地北缘的右行走滑冲断系统及其动力学

Right-lateral strike-slip thrust system and its dynamics along the northern margin of Qaidam basin

肖安成 杨树锋 程晓敢 党玉琪 陈新领 陈元忠 王亮

Xiao Ancheng Yang Shufeng Chen Xiaogan Dang Yuqi Chen Xinling Chen Yuanzhong Wang Liang

通过对于断裂系统分析和地球物理资料的解释,证实了柴达木盆地北缘西段的主要构造形成时间为上新世以后,变形样式为一系列右行走滑冲断构造。走滑冲断构造带内部的断层在平面上呈分支复合,剖面上表现为正花状构造,断层上、下盘地层层序无法直接对比。右行走滑冲断构造形成于南祁连由北向南的斜向推覆作用,而主要应力来源于柴达木地块北缘由南向北的陆内俯冲作用。用一个运动学模型解释了柴北缘的右行走滑冲断作用机制。

Interpretation of geophysical data and analysis of fault systems confirm that structures in the northern margin of Qaidam basin were formed after the Pliocene and occur as a series of right-lateral strike-slip thrusts.The faults within the strike-slip thrust belts occur as structure in sectional view,thus direct correlation of strata between the hanging wall and footwall is impossible. The formation of the right-lateral oblique thrust belts were controlled by the N-S oblique thrusting of South Qilian Orogeny and the main terrestrial stress came from the S-N intracontinental subduction of the north margin of Qaidam massive.To interpret the right-lateral strike-slip thrusting,a kinematics model is also provided.

10.11743/ogg20060407