越南大慈县金山铜锡矿花岗闪长岩SHRIMP锆石U-Pb年龄及其地质意义  

THE SHRIMP ZIRCOM U-PB AGE DATING OF GRANODIORITE OF JINSHAN CU-SN DEPOSIT AND GEOLOGICAL SIGNIFICANCE OF DAI TU,VIETNAM

作　　者：朱永清 余红平[2] 袁明伟 李帅[2] 江国文 ZHU Yong-qing;YU Hong-ping;YUAN Ming-wei;LI Shuai;JIANG Guo-wen(μExploration Branch,Yunnan Au Mining Group Company(Ltd),Kunming 650299;不详)

机构地区：[1]云南昊龙实业集团有限公司,云南鲁甸657100 [2]云南黄金矿业集团股份有限公司勘查分公司,云南昆明650299

出　　处：《云南地质》2022年第2期147-157,共11页Yunnan Geology

摘　　要：通过对越南太原省大慈县金山铜锡矿花岗闪长岩岩体及矿体进行岩相学、主微量元素分析及SHRIMP锆石U-Pb测年分析研究。金山铜锡矿nui phao花岗闪长岩侵位年龄为249.2±2.8Ma,岩体主量元素显示富钾(K_(2)O/Na_(2)O=1.27-2.40),过铝(A/CNK=1.07-1.31)和碱性。微量元素样品显示富集轻稀土(LREE)及Rb、U,相对亏损Nb,弱负Eu异常,形成于同碰撞构造环境。矿石显示与岩体相似而较低的微量元素特征。花岗闪长岩体中北北东走向断裂控制了铜锡矿体分布。本区早三叠世-晚白垩世主要有2期岩浆活动:早期为250 Ma~243.34Ma,主要为粗粒花岗岩、富钾斑状花岗岩、花岗闪长岩;第二期为85.5 Ma~81.5 Ma,岩性为细粒花岗岩。铜矿化与早三叠世花岗闪长岩有关,锡矿化与晚白垩世细粒花岗岩有关。According to SHRIMP zircon U-Pb dating of granodiorite rock body,major and trace element analysis and phase study of Jinshan Cu-Sn deposit of Dai Tu in Thai Nguyen,nui phao granodiorite emplacement age 249.2±2.8Ma of Jinshan Cu-Sn deposit,the major element shows K-rich(K_(2)O/Na_(2)O=1.27~2.40),peraluminous(A/CNK=1.07~1.31)and alkaline,trace element shows LREE rich,Rb,U relative deficit,weak negative Eu anomly,forming in syn-collision tectonic environment,ore shows trace element characteristics similar to rock body and lower.In granodiorite body,the NNE fault controls the distribution of Cu-Sn orebody.There are mainly 2 periods of magmatism in Early T-Late Cretaceous:the early period is 250Ma-243.34Ma,mainly coarse grain granite,K-rich porphyritic granite,granodiorite,the second period is 85.5Ma-81.5Ma,fine grain granite.Cu metallogenesis is in relation to Early T granodiorite,Sn metallogenesis is related with Late Cretaceous fine grain granite.

关 键 词：花岗闪长岩 锆石U-PB定年 地球化学 大慈县金山铜锡矿 越南 

分 类 号：P586[天文地球—岩石学] P595[天文地球—地质学]