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

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