准噶尔盆地构造演化分析新进展

Study on Tectonic Evolution of Junggar Basin

准噶尔盆地由准噶尔地体演化而来。准噶尔地体的前寒武系结晶基底,至少形成于800Ma前。准噶尔盆地基底具有”双层结构”,局部存在强烈减薄现象,整个下古生界,准噶尔地体一直存在稳定的地体演化机制,它经历了地体与板块并存、前缘推覆-洋壳消减和地体与板块拼贴的三个阶段后演化为盆地。根据准噶尔盆地构造分层,并结合盆地地质研究的进展,将准噶尔盆地形成及演化过程划分为6个阶段:（1）地体形成阶段;（2）地体发展演化阶段;（3）地体、板块拼贴,准噶尔盆地雏形形成阶段;（4）前陆盆地阶段;（5）陆内坳陷阶段;（6）再生前陆盆地阶段。后三阶段与油气关系密切。

Junggar Basin is one of the biggest oil and gas bearing basins in China. Junggar Basin lies among the Altaiorogen on south flank of Siberia plate, the Kazakstan plate and the Tianshan fold belt. It is a Late Paleozoic, Mesozoic, and Cenozoic compressional superimposed basin, experienced the effects Hercynian orogeny, indosinian, Yanshannian and Himalayan orogenisms and was rsulted in a complex tectonic frame work. Junggar Basin developed on the basis of Junggar terrain. The terrain consists of Precambrin crystal basement which was formed before 800Ma at least. It consists of 'dual basement and four-layers structure'. The crust thinning took place in some parts of the basin. So, the evolution falls into two stages i. e. the first stage, the evolution of the Junggar terrane and the second stage, the evolution of the basin. During the whole Lower Paleozoic, the terrane was in the stable evolution of the terrane. The terrain passed through three stages and came into being the Junggar Basin: (1) the terrane evolution; (2) the oceanic crust comsumption; (3) the accretion and collage of the terrain and the plates. Based on the structure-layers and the progress of the basin research, the formation and evolution of the J unggar Basin has divided into six stages: (1) the formation of the terrain; (2) the evolution of the terrain; (3) the collage of the terrain and the plates and the formation of the enbryonic; (4) foreland basin stage; (5) the intacontinental depression stage; (6) the regeneration foreland basin. The latter three stages are related to the accumulation of petroloum and nature gas.