祁连山地区花岗质岩浆作用及构造演化  

Granitic magmatism and tectonic evolution in the Qilian Mountain Range in NW China:A review

作　　者：朱小辉[1,2] 陈丹玲[2] 冯益民[1] 任云飞[2] 张欣[1] ZHU Xiaohui;CHEN Danling;FENG Yimin;REN Yunfei;ZHANG Xin(Research Center for Orogenic Geology,Xi’an Center of Geological Survey,China Geological Survey,Xi’an 710054,China;State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China)

机构地区：[1]中国地质调查局西安地质调查中心造山带地质研究中心,陕西西安710054 [2]西北大学地质学系大陆动力学国家重点实验室,陕西西安710069

出　　处：《地学前缘》2022年第2期241-260,共20页Earth Science Frontiers

基　　金：国家自然科学基金项目(41402051,41972058,42030307);中国地质调查局工作项目(DD20190376,DD20179395,DD20190069)。

摘　　要：祁连山在构造上是一条经历了多期构造旋回叠加的早古生代复合型造山带,花岗质岩浆作用研究对揭示其构造演化具有重要意义。锆石U-Pb年代学统计结果表明,祁连地区花岗质岩浆活动可以分为7个大的阶段,包括古元古代早期(2470~2348 Ma)、古元古代晚期(1778~1763 Ma)、中元古代晚期-新元古代早期(1192~888 Ma)、新元古代中期(853~736 Ma)、中寒武世-志留纪(516~419 Ma),泥盆纪-早石炭世(418~350 Ma)以及中二叠世-晚三叠世(271~211 Ma)。其中古元古代早期发育强过铝质高钾钙碱性S型和准铝质低钾拉斑高钾钙碱性I型花岗岩,记录了早期的陆壳增生及改造事件。古元古代晚期为准铝质弱过铝质高钾钙碱性钾玄质A型花岗岩,是Columbia超大陆裂解事件的产物。中元古代晚期-新元古代早期以过铝质-强过铝质钙碱性-钾玄质S型花岗岩为主,新元古代中期以准铝质-强过铝质钙碱性-高钾钙碱性A型花岗岩为主,分别对应Rodinia超大陆的汇聚和裂解事件。中寒武世-志留纪花岗岩是洋陆转换过程中的产物,约440 Ma加厚基性下地壳部分熔融形成的低Mg埃达克岩的广泛出现指示祁连地区全面进入碰撞造山阶段。泥盆纪-早石炭世花岗岩代表后碰撞伸展阶段岩浆岩组合,发育准铝质强过铝质低钾拉斑钾玄质等一系列花岗岩。中二叠世-晚三叠世花岗岩以准铝质弱过铝质钙碱性高钾钙碱性I型花岗岩为主,有少量弱过铝质高钾钙碱性A型花岗岩,是宗务隆洋俯冲消减以及碰撞后伸展过程的产物。The Qilian Mountain is a composite orogenic belt that has experienced multicyclic tectonic movements,and granitic magmatism plays an important role in the tectonic evolution of such an orogenic belt.According to zircon U-Pb geochronology results,granitic magmatism in the Qilian Mountain can be divided into seven major stages.The Early Paleoproterozoic(2470-2348 Ma)granitic magmatism is related to high-K calc-alkaline strongly peraluminous S-type granites and tholeiitic to high-K calc-alkaline metaluminous I-type granites,which recorded the crustal accretion and transformation events of this period.The Late Paleoproterozoic(1778-1763 Ma)granitic magmatism is predominantly associated with high-K calc-alkaline shoshonitic metaluminous to weakly peraluminous A-type granites formed as a result of the breakup of the Columbia supercontinent.The Late Mesoproterozoic to Early Neoproterozoic(1192-888 Ma)granitic magmatism is mainly related to calc-alkaline shoshonitic peraluminous to strongly peraluminous S-type granites,while the Middle Neoproterozoic(853-736 Ma)granitic magmatism is primarily associated with calc-alkaline to high-K calc-alkaline metaluminous to strongly peraluminous A-type granites,and,respectively,they correspond to the assembly and breakup of the Rodinia supercontinent.The Middle Cambrian to Silurian(516-419 Ma)granitoids are formed during ocean-continent transition,whilst the widely distributed low-Mg adakites(Ca.440 Ma),derived from the partial melting of thickened crust,indicate the Qilian orogenic belt had fully entered the collisional orogenic period.The Devonian to Early Carboniferous(418-350 Ma)granitoids are formed in the post-collisional environment and consist a series of granites with rock types ranging from tholeiitic to shoshonitic,metaluminous to strongly peraluminous.The Middle Permian to Late Triassic(271-211 Ma)granitoids are dominated by calc-alkaline to high-K calc-alkaline metaluminous to weakly peraluminous I-type granites,with small amounts of high-K calc-alkaline weakly peralumin

关 键 词：年代学 岩石地球化学 时空分布 花岗岩 祁连山 

分 类 号：P597[天文地球—地球化学]