Abstract:

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.