马边地震带发震构造背景的初步研究

A Research on the Seismogenic Tectonics of Mabian Seismic Zone

北北西向的马边—盐津隐伏深断裂是马边地震带形成的主要条件,尤其被东西向甘洛—沐川深断裂和盐津—叙永深断裂围限的段落是强震多发段。地壳表层有北北西向马边—盐津断裂组和地面微隆起带,但地表断裂与隐伏深断裂并不连通,且地表断裂走向与结构复杂多变,这是造成马边地震带强震地面破坏效应及地震影响场特点的基本原因。

As a major factor of forming the Mabian seismic zone, the Mabian-Yanjin buried deep-seated fault with trending of NNW-SSE, especially the segment between the E-W trending Ganluo-Muchuan and Yanjin-Xuyong deep-seated faults is a strong seismically active zone. There is a NNW-trending weak uplifting and Mabian-Yanjin fault group at the shallow crust. But the shallow-seated faults are not connected with the buried deep-seated fault, whatmore their orientations and geometric features are changeful ,that should be the fundamental causes which determines the character of surface rupture and seismic intensity distribution of strong earthquakes.