摘要
通过对6条区域地震大剖面的研究,揭示了川中地区基底断裂在剖面上和平面上的发育特征。指出基底断层以高角度的逆断层、下正上逆断层和正断层为主。它们在震旦纪已开始发育,在历次构造运动中都有活动。在前中生代主要处于张扭应力背景之下,在中、新生代转化为压扭应为背景。基底断裂在剖面上和平面上都成带发育,构成网格状断裂系统。它们对盖层断裂和褶皱的发育有明显的控制作用。
On the basis of the study of six regional seismic profiles, the characteristics of evolution,both on vertical and horizontal, of basement faults in central Sichuan Basin have been revealed. It ispointed out that the basement faults are mainly high angle reverse faults; and the faults showing nor-mal at lower part and reverse at upper part; as well as normal faults. These faults were formed in Sini-an, and were active during many tectonic movements later. This area was on the tension-shearing back-ground in Pre-Mesozoic Era, and compression-shearing in Meso-Cenozoic Era. These faults show zona-tion both in vertical and horizontal directions, hence, a netting fault system is formed. This system havebeen predominently controlling the development of faults and folds within the covering strata.
关键词
川中地区
基底断裂
发育
成因机制
basement fault
mechanism of faulting
structural evolution
central Sichuan area
