Abstract: To illustrate quantitatively the formation mechanism of the rightstep faults, an ela-sto-visco-plastical three-dimensional model with a discontinuous pre-existing buried fault is presented and solved numerically by a general total initial strain procedure. Body force and localized upward force at the model base as well as a rightlateral couple acting beneath the upper crust are required to develop horizontal tensional stress above the buried fault with a direction perpendicular to the long axis of these basins.

Key words: Shanxi, En-echelon graben, Mechanics of graben, Numerical modelling, Finite element

摘要： 本文在分析山西断陷盆地带的各种地质、地球物理资料的基础上,用三维粘-弹塑性有限元方法对该断陷带的形成机制进行了模拟计算。表明山西断陷盆地带的形成是地壳深部的上隆作用和北东—南西向挤压应力场在深部隐伏断裂上派生的右旋滑动共同作用的结果。地壳深部的上隆是一个主要的不可忽视的因素。

关键词: 山西, 断陷盆地, 盆地形成机制, 数值模拟, 有限元