福建平和锦溪铜(钼)矿床锆石U-Pb和辉钼矿Re-Os年龄及其地质意义  

Zircon U-Pb and molybdenite Re-Os dating for the Jinxi copper(molybdenum) deposit in Pinghe County, Fujian Province, and its geological significance

作　　者：潘天望 张达[1] 倪建辉[2] 陈泉流 袁远[1] 狄永军[1] 

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室,北京100083 [2]福建省地质矿产勘查开发局第八地质大队,福建龙岩364012

出　　处：《地球化学》2016年第2期173-189,共17页Geochimica

基　　金：中国地质调查局地质调查项目(12120113089600;1212011085472;12120114028701)

摘　　要：福建平和锦溪铜（钼）矿床是近年来上杭．云霄成矿带东段取得的重要找矿成果之一。矿床地质特征调查表明，铜（钼）矿床的形成与锦溪花岗闪长岩体具有密切的成因联系。锆石LA-ICP-MSU—Pb定年结果表明，锦溪花岗闪长岩体成岩年龄为105～107Ma；通过对矿体中辉钼矿的Re-Os同位素分析，获得其模式年龄为（105．7±1．7）Ma，与岩体成岩年龄非常相近。矿体中辉钼矿的Re含量指示钼矿成矿物质来源于地壳。结合已有研究成果，认为早白垩世晚期一晚白垩世早期（125～92Ma）东南沿海地区在古太平洋板块俯冲作用机制影响下，岩石圈的拉张伸展作用背景下导致下地壳部分熔融而引起上杭一云霄构造岩浆带发生的岩浆．热液．成矿事件是锦溪铜（钼）矿床形成的主导因素。The Jinxi deposit is one of the important achievements of ore prospecting that has been made in the eastern part of the Shanghang-Yunxiao metallogenic belt in recent years. Geological investigations show that there are coupled relationships between the Jinxi granodiorite and the copper （molybdenum） mineralization in the Jinxi copper （molybdenum） deposit. LA-ICP-MS zircon U-Pb dating has revealed that the Jinxi granodiorite was formed during 105-107 Ma approximately. The molybdenite Re-Os model age for the molybdenum ore body is （105.7±1.7） Ma, which means that the mineralization of the Jinxi copper （molybdenum） deposit might be genetically associated with the Jinxi granodiorite. The Re content of molybdenite indicates that the ore-forming materials are derived from the crust. In combination with former researches, it is concluded that the Jinxi deposit was most likely formed under an extensional setting in the continuous subduction process of the paleo-Pacific plate in southeastern China, which led to the partial melting of the lower crust duiring the late Early-Cretaceous to early Late-Cretaceous （92-125 Ma） in the Shanghang-Yunxiao tectono-magmatic belt.

关 键 词：锆石U-Pb年龄 RE-OS同位素年龄 锦溪铜(钼)矿床 上杭-云霄成矿带 平和 

分 类 号：P597.3[天文地球—地球化学] P618.41[天文地球—地质学]