准噶尔盆地的原型和构造演化

文中讨论了以下三个问题:(1)洋-陆转换时限和中、晚石炭世盆地原型。根据准噶尔盆地及其邻区的构造演化及岩浆活动研究,洋-陆转换时限应为早石炭世末,中、晚石炭世裂陷槽是由于造山期后伸展塌陷作用产生的;(2)二叠纪—早更新世陆内盆地的原型。根据陆内盆地的鉴别标志,提出了二叠纪盆地为陆内裂谷—裂谷期后弱伸展坳陷—弱缩短挠曲坳陷,三叠纪、侏罗纪、白垩纪和第三纪为弱伸展或稳定大陆内坳陷和陆内前陆坳陷或弱缩短挠曲坳陷交替的叠合盆地;(3)准噶尔盆地原型和构造演化对油气分布的控制作用。

Prototype and tectonic evolution of the Junggar Basin, northwestern China

Three topics are discussed in this paper:(1) the time of ocean-continent transformation and the prototype of the Middle-Late Carboniferous Junggar basin.Based on tectonic evolution and magmatic activity of the Junggar basin and its surroundings,it is recognized that the ocean-continent transformation occurred at the end of the Early Carboniferous,and that a rifted trough of Middle-Late Carboniferous developed because of post-orogenic extensional collapse;(2)the prototypes of Permian-Early Pleistocene basins.Based on criteria of intracontinental basins,it is suggested that Permian basins belong to rift,post-rift weak extensional depressions,and weak contractional flexural depressions.Triassic,Jurassic,Cretaceous and Tertiary basins are superposed,which consist of weak-extensional or stable intracontinental depressions alternating with intracontinental foreland or weak shortening flexural depressions;(3)hydrocarbon occurrence in the Junggar basin was controlled by prototype and tectonic evolution.