青藏高原东缘岷江断裂构造特征、变形序列和演化历史

Geological Features, Deformation Sequence and Evolution of the Minjiang Fault on the Eastern Margin of the Qinghai-Tibet Plateau

岷江断裂是青藏高原东缘的重要边界断裂,呈南北向延伸。地球物理场背景及地质演化历史的研究表明,岷江断裂是一条具有长期发展历史的大断裂。岷江断裂的活动具有多期次性:晚古生代时已经存在,为张性断裂;中生代受北东-南西方向挤压,产生右旋走滑运动;新生代以来,区域应力转变为北西-南东向挤压,随着青藏高原东缘物质向南东方向逃逸,岷江断裂在逆冲的同时伴随着左旋走滑,现在的GPS测量结果显示,岷江断裂仍在进行左旋运动。

The longitudinal Minjiang fault is one of the most important faults on the eastern margin of the Qinghai-Tibet Plateau. Study of the geophysical fields and the geological evolution shows that the Minjiang fault is a long-lived fault. In the Late Paleozoic, it began to act as an extension fault, and in the Mesozoic it became a right-lateral strike-slip fault under the NE-trending stress. In the Cenozoic, it is a thrust left-lateral with strike-slip resulting from NW-trending compressive stress. The GPS shows that it is a still left-lateral strike-slip.