福建平和钟腾铜矿床成岩成矿时代研究  

Study on the Intrusive Ages of the Granites and Metallogenic Age from Zhongteng Copper Deposit,Pinghe,Fujian Province

作　　者：任程昊 佘宏全[1] 柯昌辉[1] 孙衍东 周群茂 焦天龙 李保亮 REN Chenghao;SHE Hongquan;KE Changhui;SUN Yandong;ZHOU Qunmao;JIAO Tianlong;LI Baoliang(Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China)

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《现代地质》2022年第6期1447-1464,1485,共19页Geoscience

基　　金：中国地质调查局项目(DD20201173,DD20221684);中国地质科学院矿产资源研究所基本业务费项目(KK2108)。

摘　　要：钟腾铜矿床为位于华夏板块东南缘上杭—云霄构造-岩浆成矿带上的岩浆热液型矿床。岩石地球化学分析表明矿区3种主要花岗质岩石均属于高钾钙碱性系列岩石,具有高钾、富碱、贫硅、低钛的特征,部分岩石有过铝质的特点,轻稀土元素富集,具有弱负铕异常。微量元素以富集大离子K、Rb、Th等亲石元素,亏损Nb、Ta、Ti等高场强元素为特征。LA-ICP-MS锆石U-Pb测年获得矿区3种岩石年龄分别为(103.5±0.4)Ma、(102.2±0.4)Ma、(103±0.4)Ma,锆石εHf(t)值在-2.9~2.0,两阶段模式年龄(T DM2)为1.04~1.35 Ga。矿石辉钼矿的Re-Os同位素测年获得等时线年龄为(105±2.5)Ma,说明成矿主要与燕山晚期花岗岩侵入有关。综合本次研究及相关区域资料,认为钟腾铜矿区的花岗岩为I型花岗岩,花岗岩及相关矿床形成于东南沿海地区110~90 Ma期间的古太平洋板块向西俯冲的大陆边缘背景。Zhongteng Cu deposit,located in the Shanghang-Yunxiao tectonic magmatic metallogenic belt on the southeast margin of Cathaysian Plate,is a magmatic hydrothermal deposit.Geochemistry of the three types of granitic intrusive rocks from the ore deposit indicates that they belong to high potassium calc-alkaline series,characterized by high K 2O,low Si and low TiO_(2);some rocks belong to peraluminous.Analysis on REE and trace elements has shown the granites are enriched in light rare earth elements,have weak negative europium anomaly,enriched in large ion lithophile elements(K,Rb,Th,etc.),and depleted in high field strength elements(Nb,Ta,Ti,etc.).Zircon LA-ICP-MS dating of the granites gives(103.5±0.4)Ma,(102.2±0.4)Ma,(103±0.4)Ma,respectively.ZirconεHf(t)values of granites is between-2.9 and 2.0,the two-stage model ages(T DM2)are 1.04-1.35 Ga.Re-Os isotopic dating on the molybdenite samples from the ore body obtained an isochronic age of(105±2.5)Ma,indicating that the formation of Zhongteng copper deposit is mainly related to intrusive rocks formed at late stage of Yanshan period.Based on this study and newly other study results,it is reasonably to considered the granites at Zhongteng copper deposit belong to I-type,its formation and related mineralization were related to subduction of the Paleo-Pacific Plate occurred at southeast coastal area during late Early Cretaceous Period(110-90 Ma).

关 键 词：地球化学 钟腾铜矿床 锆石U-PB测年 辉钼矿Re-Os测年 HF同位素 福建平和 

分 类 号：P618.41[天文地球—矿床学] P611.11[天文地球—地质学]