准噶尔盆地结构构造与油气田分布

准噶尔盆地是晚古生代以来多期形成的复合叠加前陆盆地。原型盆地的成盆期包括：晚石炭—二叠纪碰撞造山期的碰撞前陆盆地；三叠纪—早、中侏罗世与北天山、西准噶尔山、阿尔泰山、博格达山复活有关的前陆盆地，这两个阶段有多个沉积—沉降中心；与北天山均衡活动有关的晚侏罗世—白垩纪—早第三纪前陆盆地；晚第三纪—第四纪与北天山强烈复活有关的前陆盆地。每个坳陷由褶皱—冲断带、陡坡带、沉降中心、缓坡带和前隆组成。三个隆起为叠加的前隆。部分前隆因后期改造已不明显。克拉玛依坳陷是最有利的生油气坳陷，北天山山前侏罗纪前陆坳陷次之，潜力巨大。克拉美丽山前石炭—二叠纪坳陷、博格达山前二叠纪坳陷后期改造强烈，对油气破坏较大。北天山山前三叠纪坳陷也有一定的生烃条件。乌伦古坳陷后期沉降较小，成熟度较低，难于形成中型以上规模的油气田。

THE TECTONIC EVOLUTION,ARCHITECTURE AND PETROLEUM DISTRIBUTION IN THE ZHUNGAER BASIN IN CHINA

Zhungaer Basin is a composite and superimposed foreland basin since late Paleozoic.Its proto basins were formed in the fo llowing tectonic settings:1) plate convergence; 2)plate collision; 3)in front of the reacted mountain belts; 4)nearby inverted aulacogen; 5)intraplate.The evolutionary periods included: 1)the Permian proto foreland basin was formed in the plate collision setting and in front of the inverted aulacogen,and was distributed along the margin of Zhungarer massif; 2)The Trias Middle Jurassic foreland basin was related to the reactivated Tianshan Mountain,Altay Mountain,west Zhungaer Mountain,etc.; 3)the later Jurassic Paleogene proto foreland basins were related to the moderate reactivated Tianshan Mountain; 4)The Neogene Quaternary foreland basins were controlled by the mightily reactivated Tianshan Mountain belt.The differences among the adjoining orogenic belts in space and time and intensity controlled the formation of unique architecture of the Zhungaer Basin.Therefore,with all the influences,the Zhungaer Basin is divided into 6 depressions and 3 uplifts.Each proto basin is composed of thrust fold belt,steep slope,sub depression,gentle slope and forebulge.Some large uplifts were formed by the stack of forebulges,and the central depression was formed by the stack of lows.The front of thrust belt could be classified into 4 types:1)The front of thrust belt had thick cover early but damaged later; 2)those with thin cover; 3)those with thick cover early but damaged later; 4)thin cover but damaged later.The former had better prospect.