巴彦浩特盆地构造特征及含油气远景初步评价

Tectonic Features in Bayanhot Basin and Preliminary Evaluation of its Oil Potential

巴彦浩特盆地是一个上叠于阿拉善地块之上的复合盆地．盆地可划分成五个一级构造单元，十二个次一级构造单元。盆地中发育有五种构造地层组合．断裂对盆的形成和发育起明显的控制作用，巴彦乌拉山断裂为一深切基底的铲地正断层，该断裂控出了西部拗陷带的形成，其活动强度自北向南减弱．伊南断裂带控制了伊和凹陷的形成，该断裂带中段活动强度最大；查汗断裂具明显的左旋走滑特征。盆地中发育多种构造样式，主要有：叠瓦状冲断层、滚板构造、牵引褶皱、铲形正断层、滚动背斜、“垒一堑”构造等。石炭系是盆地内主要的生油层系，它广泛发育并具良好圈闭条件的东部地区和南部地区有较好的油气远景。

A compound basin superimposed on Alxa Massif,Bayanhot Basin can be divided into 5 first units and 12 second units of tectonics that form 5 tectono-stratigraphic assemblies in the basin.Faults are the main factor in the formation and evolution of the basin.With the features of listric fault,Bayanwula Shan Fault controls the formation of the western depression belts.with its active intensity declining from north to south.Yinan Fault Belt controls the formation of Yihe depression,with the most active intensity in its middle part.Chahan Fault is a strike-slip fault with an obvious sinistral movement.The structural style found in the basin includes imbricated thrust zone,trapdoor structure,drag fold,listric fault,rollover anticline,horst-graben structure and the like.As the main oil-bearing bed in the basin,the Carboniferous system in the eastern and southerrn depression zones is provided with good trap conditions,thus possessing a favourable oil and gas potential.