准噶尔多旋回叠合盆地的形成与演化

Formation and Evolution of Multicycle Superimposed Basins in Junggar Basin

准噶尔盆地是在拼合增生的微陆块和古生代岛弧带基底上发展起来的大型复合叠合盆地,受控于古亚洲洋和周边造山带的演化,显生宙以来盆地经历了五大构造演化旋回,即寒武纪—中志留世的北准噶尔洋伸展—消减旋回、晚志留世—早石炭世的克拉美丽有限洋盆拉张聚敛旋回、晚石炭世—三叠纪的古亚洲洋全面消亡、早侏罗世—古近纪的陆内断坳旋回和新近纪—第四纪的压扭强挤压聚敛造山旋回。伸展期原盆的稳定地层层序往往发育良好的烃源岩,聚敛期原盆受到改造,成为构造圈闭发育或油气聚集的时期;此外,通过恢复盆地的演化过程指出泥盆—石炭系是未来准噶尔盆地寻找油气勘探大场面的新领域。

Junggar Basin is a large composite and superimposed basin, which is developed from the basement of micro- plate after suture andaccretion and Paleozoic island-arc belts, controlled by the evolution of paleo-Asian ocean and its peripherial orogenic belt. Since Phanerozoiceon, the basin has undergone five cycles of tectonic evolution, i.e. the extension-subduction cycle of Cambrian-middle Silurian north Junggarocean, the pull-apart and convergent cycle of late Silurian-early Carboniferous Kelameili limited ocean-basin, fully extinct cycle of lateCarboniferous -Triassic paleo-Asian ocean, the intra-continent fault-depression cycle during the period of early Jurassic-Eogene and the strongtranspressional and convergent orogenic cycle during the period of Neogene and Quaternary. During the extending period, the stable sequencesof original basin often develops better source rock, and in convergent period, the proto-type basin was suffered from reconstruction, and thisperiod becomes the development stage of structural trap or oil/gas accumulation. In addition, after resuming the evolution process of the basin,it is pointed out that the Devonian-Carboniferous will become new target for oil/gas exploration in Junggar Bain in the future.