Abstract: The Junggar paleocontinent was in an uplifted state from the end of Precambrian to middle Palaeozoic and was the main source for sediments in the paleomarginal sea. The Hercynian orogeny was an important turning point in geologic history of the area. The marginal sea was subjected to strong geasynclinal folding, which resulted in luigh mountain ranges. The Junggar paleo-continent began to subside and shrink to develop into a negative tectonic elewent-intermontane basin. However, the Junggar paleocontinent was still in erosion in the period. At the same time, three sets of fault systems were formed, that is, the EW-trending deep fault zone in Tianshan piedmont,the NE-trending great fault zone or nappe tectonic zone in Karamay and the NWW-NW-trending fault zone on the south side of the Wulungu trough and Kalameili piedmont.

摘要： 准噶尔古陆自前寒武纪末至古生代中期始终处于隆起剥蚀状态,是古边缘海沉积的主要物源区.海西褶皱运动,在本区地质历史上是一个重大的转折,边缘海遭受强烈的地槽褶皱,形成高峻的地槽褶皱山脉,准噶尔古陆开始沉降、萎缩,逐渐向负向构造单元-山间盆地发展,但这一时期的准噶尔古陆仍然呈剥蚀状态,同时,在准噶尔古大陆边缘形成三大断裂构造带,即东西向天山山前深大断裂带、北东向克拉玛依大逆掩断裂带或推谈构造带、北西一北西西向乌伦古坳陷南侧断裂带和克拉美丽山前断裂带. 晚古生代晚期,准噶尔古陆继续下沉,海水逐渐由北而南,由西向东退出,沿准噶尔古大陆边缘分布的山前海沟也逐渐向陆相坳陷盆地过渡,形成了早期准噶尔陆相盆地的相互分割的四大沉积坳陷.在四大沉积坳陷中,沉积了巨厚的磨拉式建造,成为盆地内主要的生油坳陷. 准噶尔古大陆边缘断裂构造发育,这些断裂构造既是油气运移通道,又是油气聚契的有利场所,同时它又能起到对油气遮挡封闭的作用.古大陆边缘斜坡带对于油气藏的形成同样是有利的.因此,准噶尔古大陆边缘是寻找油气的远景地带.