现代地质2023，Vol.37Issue(6)：1609-1623,15.DOI:10.19657/j.geoscience.1000-8527.2023.010
新疆东昆仑土窑洞地区新元古代早期侵入岩年代学、地球化学及其构造意义
Geochronology,Geochemistry and Tectonic Implications of Early Neoproterozoic Tuyaodong Intrusive Rocks in the East Kunlun Orogen in Xinjiang
摘要
Abstract
The western section of the East Kunlun Orogen(EKO)developed Proterozoic granites,and the mag-matic timeframe and tectonic setting remain controversial,which restricts our understandings of the Proterozoic EKO tectonic evolution.Here,we investigate the regional tectonic evolution via LA-ICP-MS zircon U-Pb dating and whole-rock elemental analysis of the Tuyaodong granitoids in the western EKO.The monzonite and syenogranite show gneissic structure and have Al-rich minerals such as muscovite.The rocks have high contents of SiO2(67.37％-76.35％),Al2O3(12％-14.25％),and K2O(1.59％-6.01％),but low TiO2(0.16％-0.56％),Na2O(2.13％-3.86％),and CaO(0.9％-4.25％),with average A/CNK=1.02 and A/NK=1.47.The chondrite-normalized REE patterns and primitive mantle-normalized spider-diagram of the monzonite and syenogranite are similar,which are enriched in LREE((La/Yb)N=5.04-16.76)and have obvious negative Eu anomaly(average δEu=0.47).The primitive mantle-normalized trace element dia-grams show that the rocks are enriched in Rb,K and Th,depleted in Nb,Ba,Sr,P and Ti,and have high CaO/Na2O ratios(0.35 to 1.41).The zircon 206Pb/238U weighted average age of the granite is(932.7±2.4)Ma,indicating that the rock was formed in the Early Neoproterozoic.Comprehensive analysis suggests that the Tuyaodong monzonite and syenogranite belong to S-type and their magmas were originated from melting of clastic sediments with minor muddy components in the upper crust.They may have formed in the same collisional extrusion setting,which is in response to the Rodinia supercontinent assembly in the EKO.关键词
S型花岗岩/新元古代/东昆仑/Rodinia超大陆/土窑洞Key words
S-type granite/Neoproterozoic/East Kunlun Orogen/Rodinia super-continent/Tuyaodong分类
天文与地球科学引用本文复制引用
席振,马德成,李欢,高光明,向夏楠..新疆东昆仑土窑洞地区新元古代早期侵入岩年代学、地球化学及其构造意义[J].现代地质,2023,37(6):1609-1623,15.基金项目
国家自然科学基金资助项目(42101005) （42101005）
新疆维吾尔自治区中央返还两权价款项目(K15-1-LQ06) （K15-1-LQ06）
有色金属成矿预测与地质环境监测教育部重点实验室(中南大学)开放基金资助项目(2022YSJS13) （中南大学）
湖南省教育厅科学研究优秀青年项目(19B097). （19B097）
