羌塘盆地羌北坳陷托纳木穹窿成因分析

Origin of Tuonamu Dome in Qiangbei Depression of Qiangtang Basin

通过对羌塘盆地羌北坳陷托纳木地区构造样式及构造组合形态的解析,认为该地区存在收缩及走滑2种构造样式,可解析出逆冲-推覆、帚状、环状和辐射状等4种构造组合形态;托纳木穹窿是在统一的南北向应力场中,为前期收缩、后期右行走滑作用下形成的,是边界条件改变后局部应力场的反应。正确分析研究区构造应力场特征,对认识区内油气运移具有重要的意义。

This paper analyzes the structural style and assemblage configuration in Tuonamu area in Qiangtang basin and suggests that there exist two structural styles of contraction and slip,and four assemblage configurations such as overthrust/nappe-like,broom-like,ring-like and radiat structures.The Tuonamu dome was formed by pre-contraction and post right-slip actions under unified SN trending stress field,as a reaction of local stress field under the boundary condition changes.This study is helpful for proper recognition of hydrocarbon migration in this area.