酒西盆地老君庙逆冲断裂带及其演化

这是一条典型的逆冲断裂带,由老君庙和庙北两逆冲断层组成。断面上陡下缓,向下顺上石炭统太原组软弱层滑脱。该构造带沿走向从东至西位移量和缩短量逐渐减少,褶皱幅度减小但宽度增大,逆冲岩席厚度由薄增厚。岩席厚度的变化可能是导致其它变形差异的主要原因。断裂带的演化过程可分为四个阶段。褶皱尤其是断裂是从东向西、由南向北逐渐发育的。

LAOJUNMIAO THRUST BELT IN JIUXI BASIN AND ITS EVOLUTION

Laojunmiao thrust belt,a tipical one,consists of Laojunmiao thrustand north Laojunmiao thrust.The fault planes have a listric feature,slip-ped down along the soft layer of the Taiyuan Formation.The variationfrom east to west in the belt as follows:the displacement and shorteningdecrease gradually;the fold amplitude decreases but its width and the thrustsheet thick ness increase.The variation of the thrust sheet thickness isprobably the main factor leading to other deformation.The evolution process of the Laojunmiao thrust belt that formed duringthe Himalayan movement can be divided into four stages:prethrus stage,embryomic stage,young stage and mature stage.The folds,especially thefaults developed gradually from east to west and from south to north.The deep structures of the belt,including the thrus sheet of north Laojun-miao and the structures in the Lower walls,are favourable for hydrocarbonaccumulation and are new fields for oil exploration.