南阿尔金造山带西段高压—超高压变质岩特征及构造意义  

Characteristics and tectonic significance of high-ultrahigh-pressure metamorphic rocks in the west part of the South Altun orogenic belt

作　　者：冯欣 侯红星 邵兴坤 薛彦萍 秦丹鹤 FENG Xin;HOU Hongxing;SHAO Xingkun;XUE Yanping;QIN Danhe(Langfang Center for Integrated Natural Resource Survey,China Geological Survey,Langfang 065000,Hebei,China)

机构地区：[1]中国地质调查局廊坊自然资源综合调查中心,河北廊坊065000

出　　处：《矿产与地质》2023年第2期279-288,共10页Mineral Resources and Geology

基　　金：中国地质调查局项目(编号DD20160079)资助。

摘　　要：江尕勒萨依地区位于东昆仑西段—南阿尔金造山带,地处秦—祁—昆造山带西段,本次在该区部署实施了1∶5万基础地质调查工作,对该区高压—超高压变质岩的主要类型、地质特征、岩石学和年代学特征进行了分析,详细讨论了其变质期次和温压条件,并对其折返机制及构造意义进行了研究,将南阿尔金早古生代俯冲碰撞杂岩带的构造演化过程划分了五个阶段:洋盆扩张阶段(622~517 Ma),洋壳俯冲阶段(517~500 Ma),陆壳深俯冲阶段(500~487 Ma),俯冲板片断离及折返阶段(460~451 Ma)及碰撞后伸展阶段(425~385 Ma)。从而重建了东昆仑西段—南阿尔金地区早古生代以来的地质构造演化历史,对于探讨该区壳-幔相互作用、洋-陆转换及大陆地壳演化等地球动力学过程等具有十分重要的科学意义。Jianggalesayi area is located in the west of East Kunlun-South Altun orogenic belt,tectonically belonging to the western segment of Qinling-Qilianshan-Kunlunshan orogenic belt.In this paper,the main types,geological properties and petrological and chronological features of high-ultrahigh-pressure metamorphic rocks in this area are analyzed.The metamorphic stage and temperature pressure condition are also discussed in detail.Based on these,the tectonic evolution of the early Paleozoic South Altun subduction and collision complex belt can be divided into five stages,oceanic basin spreading(622-517 Ma),oceanic crust subduction(517-500 Ma),continental crust subduction(500-487 Ma),subduction plate detachment and exhumation(460-451Ma)and post collision extension(425-385 Ma).Combined with regional data,it has established for the early Paleozoic tectonic evolution of the western segment of East Kunlun-South Altun area,which is greatly significant for discussing the deep geodynamic processes,such as crust-mantle interaction,ocean-continent transition and continental crust evolution.

关 键 词：高压—超高压变质岩 岩石学特征 构造意义 南阿尔金造山带 

分 类 号：P588.3[天文地球—岩石学]