新疆西昆仑独尖山地区二云母二长花岗岩岩石地球化学、锆石U-Pb年龄与Hf同位素特征  

Geochemistry,zircon U-Pb age and Hf isotopic characteristics of two-mica monzonitic granites in Dujianshan area ofWestern Kunlun,Xinjiang

作　　者：张宇 唐名鹰 何玉良 崔霄峰 张东阳[6] 朱明帅 ZHANG Yu;TANG Mingying;HE Yuliang;CUI Xiaofeng;ZHANG Dongyang;ZHU Mingshuai(Henan Academy of Geology,Zhengzhou 450016,Henan,China;Henan Key Laboratory of Metal Mineral MineralizationGeological Processes and Resource Utilization,Zhengzhou 450016,Henan,China;Henan Engineering Technology Center on Non-ferrous Metals Ore-prospecting,Zhengzhou 450016,Henan,China;The 8th Institute of Geology and Mineral Exploration of Shandong Province,Rizhao 276826,Shandong,China;Henan Institute of Geological Sciences Co.Ltd,Zhengzhou 450001,Henan,China;State Key Laboratory of Geological Processes and Mineral Resources,Wuhan 430074,Hubei,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]河南省地质研究院,河南郑州450016 [2]河南省金属矿产成矿地质过程与资源利用省级重点实验室,河南郑州450016 [3]河南省有色金属深部找矿工程技术研究中心,河南郑州450016 [4]山东省第八地质矿产勘查院,山东日照276826 [5]河南省地质科学研究所有限公司,河南郑州450001 [6]地质过程与矿产资源国家重点实验室,湖北武汉430074 [7]中国科学院地质与地球物理研究所,北京100029

出　　处：《中国地质》2023年第4期1203-1216,共14页Geology in China

基　　金：新疆维吾尔自治区地质勘查基金中心项目(K15-1-LQ21);中国矿产地质志项目(DD20221695、DD20190379、DD20160346)共同资助。

摘　　要：【研究目的】为了进一步了解西昆仑松潘—甘孜陆块西北缘巴颜喀拉弧后盆地的构造演化。【研究方法】对西昆仑东缘独尖山地区二云母二长花岗岩进行了岩相学、地球化学、LA-ICP-MS锆石U-Pb年龄和Hf同位素测试。【研究结果】LA-ICP-MS锆石年代学研究揭示独尖山地区二长花岗岩成岩年龄为(219.9±1.2)~(227.1±1.5)Ma,为晚三叠世花岗岩。岩石主量元素、微量元素和Hf同位素分析结果揭示该二长花岗岩属高钾钙碱性系列,准铝质—弱过铝质,具岛弧和同碰撞花岗岩特征,物质来源具有壳幔物质混合的特点。【结论】结合区域大地构造演化,推测独尖山地区在晚三叠世末期处于碰撞后伸展环境,早期洋-陆俯冲阶段形成的岛弧和同碰撞物质通过部分熔融在研究区内形成了后碰撞花岗岩。This paper is the result of geological survey engineering.[Objective]The study aims to further understand the tectonic evolution of the back-arc basin of Bayankera,the northwestern margin of Songpan-Ganzi block,Western Kunlun.[Methods]In this paper,the authors present petrographical,lithogeochemical,LA-ICP-MS zircon U-Pb geochronological and Hf isotopic data for the two-mica monzogranite in Dujianshan.[Results]LAICP-MS zircon geochronology study reveals that the monzogranites in the Dujianshan area crystallized at(219.9±1.2)-(227.1±1.5)Ma,indicative of the Late Triassic plutons.The results of major elements,trace elements and Hf isotope reveal that the monzogranites are metaluminous-weakly peraluminous rocks,belongs to the high potassium calcium alkaline series and exhibit characteristics of island arc and collisional granites.The source rocks of granites were generated from partial melting of a mixture of crust-mantle materials.[Conclusions]Combined with the regional tectonic evolution,it is speculated that the Dujianshan area is in a post collision extension environment at the end of the Late Triassic,and the island arc and syn-collision materials formed in the early ocean continent subduction stage partially melted to form post collision granite in the area.

关 键 词：二云母二长花岗岩 岩石地球化学 LA-ICP-MS锆石U-PB年龄 Hf同位素 后碰撞花岗岩 西昆仑 地质调查工程 

分 类 号：P597[天文地球—地球化学]