Abstract: In this paper, the results of 3-D normal and inverse gravity calculus had been-analysed and interpreted, and it was suggested that the gravity gradient belt of Long-menshan Mt. is not a simple slope or steep step and that a serious of deep seismo-geological problems, such as the rang of the gravity gradient belt, the relationship between shallow/deep forms of the seismic-faults, and the complicated sub-structures of the whole mentioned gravititional gradient belt should be studied and understood further. Close coordinate between the two disciplinaries of seismo-geology and geophysics can perhaps-answer the mentioned problems. Such a way of research can also discover the regularity of pregnancy and occurrence of strong earthquakes in the gravity gradient belt of Longmenshan Mt. as well as the whole North-South seismic activity region. They are significance for the earthquake prediction and for the engineering seimology, and the-contents of geotectonics will be enriched.

Key words: Longmenshan Mts of Sichuang Province, Gravity gradienr belt, Gravity anomaly, Crustal thickness, Nappe structure

摘要： 本文分析解释了三维重力正、反演的计算结果,提出龙门山重力梯度带并不是一个简单的壳幔斜坡或陡坎。并进一步指出该重力梯度带的范围、发震断裂的深浅关系、次级构造的存在及其复杂图象等一系列深部地震地质问题都有待于揭示和认识。地震地质和地球物理两个学科的密切配合有可能回答上述问题,找出强震在龙门山重力梯度带乃至整个南北地震活动带内的蕴育发生规律。这对地震预报和工程地震都是有意义的,也将丰富大地构造的研究内容。

关键词: 四川龙门山, 重力梯度带, 重力异常, 地壳厚度, 推覆构造