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本文在野外地质调查基础上,通过对西准噶尔花岗岩类年代学的研究,厘定各期构造岩浆事件的时限,反演西准噶尔造山带构造演化过程。研究结果表明,西准噶尔岩浆活动划分为3个时期。晚志留世—早泥盆世花岗岩类主要为谢米斯台花岗岩类、赛尔花岗岩类及阿克乔克花岗岩类,结合区域地质背景及阿克乔克花岗闪长岩具有典型的埃达克岩地球化学特征,推测阿克乔克埃达克岩可能是大洋板片俯冲过程中经过脱水发生部分熔融形成的;早石炭世花岗岩类主要分布在扎尔马—萨吾尔岩浆弧地区,这一时期的花岗岩类可能是额尔齐斯蛇绿岩所代表的古大洋向南俯冲脱水引发上覆地幔楔部分熔融或者部分熔融形成的玄武岩浆底侵作用引起中、下地壳物质部分熔融的结果,指示俯冲的古大洋在早石炭世期间未闭合碰撞;晚石炭世—早二叠世的花岗岩类在整个西准噶尔地区都有分布,形成于后碰撞构造环境,表明西准地区进入了陆内构造演化阶段。
Based on the field geological survey, based on the study of the granitoid chronology of the West Junggar, the time limit of tectonic magmatism in each stage is determined and the tectonic evolution of the West Junggar orogenic belt is retrieved. The results show that the magmatic activity in western Junggar is divided into three periods. Late Silurian - The Early Devonian granites are mainly comprised of the Chemisite granites, Purcell granites and Akechuk granites. Combined with the regional geological background and the Akechuk granodiorite, It is speculated that the Akechukadake rock may be partially melted by dehydration during the subduction of the oceanic slab. The Early Carboniferous granitoids are mainly distributed in the Zalema-Uigur magma arc region A period of granitoids may be the result of partial melting of the middle and lower crustal materials caused by basaltic magma underplating caused by partial subduction or partial melting of the upper mantle wedge induced by the subduction of the ancient ocean represented by the Ordos ophiolite Indicating that the subducted Paleo-Ocean did not collide during the Early Carboniferous. Late Carboniferous-Early Permian granitoids were distributed throughout the West Junggar region and formed in the post-collision tectonic setting, indicating that the West Zone had entered the intracontinental Tectonic evolution stage.