南天山古生代板块构造演化

PALEOZOIC PLATE TECTONIC EVOLUTION OF SOUTHERN TIANSHAN

据南天山古生物地层、古地磁、岩石地球化学和同位素年龄等资料的综合分析结果;认为该区在奥陶纪—二叠纪曾为古大洋。最初裂开为大洋是以震旦纪贝义西组(Z_1b)大陆裂谷火山喷发为标志,从震旦纪—奥陶纪完成了从裂谷到被动大陆边缘海盆的演化;志留纪—泥盆纪南天山洋壳向哈萨克斯坦板块之下俯冲,泥盆纪末至石炭纪早期,塔里木板块与哈萨克斯坦板块发生陆-陆碰撞。石炭纪—早二叠纪在南天山仍存在一个向西开口的前陆残余海盆。它最终关闭于二叠纪。

The synthetic analyses based on paleontologic stratigraphy, paleomagnetics, petrogeo-chemistry, and isotopic ages show that a paleo-ocean should have existed in Southern Tianshan during the Ordovician-Permian. The earliest rifting was marked by the continental rift eruption of the Sinian Beiyixi Formation (Z1b). From the Sinian to Ordovician, the evolution from a rift to a passive continental-margin ocean-basin was completed in the Silurian and Devonian, the oceanic crust of southern Tianshan began to be subducted beneath the Kasakstan plate. In the terminal Devonian to the Early Carboniferous, the oceanic crust was consumed at all, so the continent-continent collision occurred between the Tarim and Kasakstan plates. In the Carboniferous-Early Permian a sea basin opening to the west still existed in Southern Tianshan and it was closed finally in the Permian.