湘南黄沙坪和宝山铅锌多金属矿床成矿时代及成矿物质来源:来自闪锌矿Rb-Sr同位素的证据  

Metallogenic Ages and Sources of Metallogenic Materials of the Huangshaping and Baoshan Pb-Zn Polymetallic Deposits in Southern Hunan Province:Evidence from Rb-Sr Isotopes of Sphalerite

作　　者：卢友月[1,2] 杨长明 程顺波 黄富年[3] 李茂平 王兀升 唐峰 曹荆亚 夏杰 付建明 张遵遵[1,2] 杨齐智 LU You-Yue;YANG Chang-Ming;CHENG Shun-Bo;HUANG Fu-Nian;LI Mao-Ping;WANGWu-Sheng;TANG Feng;CAO Jing-Ya;XIA Jie;FU Jian-Ming;ZHANG Zun-Zun;YANG Qi-Zhi(Research Center for Petrogenesis and Mineralization of Granitoid Rocks,China Geological Survey,Wuhan 430205,Hubei,China;Wuhan Center of China Geological Survey(Central South China Innovation Center for Geosciences),Wuhan 430205,Hubei,China;Mineral Resources Investigation Institute of Hunan Province,Changsha 410100,China;Hunan Baoshan nonferrous metals mining Co.,Ltd,Guiyang 424400,Hunan,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,Guangdong,China)

机构地区：[1]中国地质调查局花岗岩成岩成矿地质研究中心,湖北武汉430205 [2]中国地质调查局武汉地质调查中心(中南地质科技创新中心),湖北武汉430205 [3]湖南省矿产资源调查所,湖南长沙410100 [4]湖南宝山有色金属矿业有限责任公司,湖南桂阳424400 [5]南方海洋科学与工程广东省实验室(广州),广东广州511458

出　　处：《华南地质》2022年第3期472-485,共14页South China Geology

基　　金：中国地质调查局花岗岩成岩成矿地质研究中心开放基金课题(PMGR202008和PMGR2020009);中国地质调查局项目(DD20221689和DD20190154)

摘　　要：湘南地区位于EW向南岭成矿带与NE向钦杭成矿带的交汇部位。区内矿床按元素组合及其与相关岩体的关系大致可分为两大类:一类是与酸性岩浆岩有关的钨、锡、铌、钽多金属矿床,另一类是与中酸性岩浆岩有关的铜、钼、铅、锌、金多金属矿床。本文对两类矿床中具有代表性的黄沙坪和宝山大型铅锌多金属矿床的闪锌矿分别进行了Rb-Sr同位素研究,获得它们的闪锌矿Rb-Sr等时线年龄分别为143±1 Ma(MSWD=1.00)和141±4 Ma(MSWD=0.99),表明两矿区存在早白垩世成矿作用;同时获得两个矿床闪锌矿的(^(87)Sr/^(86)Sr)值分别为0.72521±0.00543和0.70985±0.00013,结合前人研究成果,认为黄沙坪铅锌矿成矿物质主要来源于陆壳,而宝山铅锌矿成矿物质主要为壳幔混合来源。该成果对深化湘南矿集区不同类型矿床年龄谱系、成矿规律和找矿方向提供了数据支持。Southern Hunan Area is located at the intersection of the EW-trending Nanling Metallogenic Bel and the NE-trending Qinhang Metallogenic Belt.The deposits in this area can be roughly divided into two categories according to the element associations and their relationships with the related magmatic rocks:one is the W-Sn-Nb-Ta polymetallic deposits related to the acidic magmatic rocks,and the other is the Cu-Mo-Pb-Zn-Au polymetallic deposits related to the intermediate-acidic magmatic rocks.In this study,the Rb-Sr isotope studies of sphalerites from the Huangshaping and Baoshan large-scale Pb-Zn polymetallic deposits have been carried out.The calculated Rb-Sr isochron ages of sphalerites from the Huangshaping and Baoshan are 143±1 Ma (MSWD=1.00) and 141±4 Ma (MSWD=0.99) respectively,indicating that their metallogenic ages are Early Cretaceous.Meanwhile,the obtained (^(87)Sr/^(86)Sr)values of sphalerites from the two deposits are 0.72521±0.00543 and 0.70985±0.00013,respectively.Combined with the previous research,it is believed that the metallogenic materials of the Huangshaping Pb-Zn ores were mainly derived from the continental crust,while those of Baoshan Pb-Zn ores were mainly derived from the mixed source of crust and mantle.These research results have provided the data support for a deeper understanding of the age spectra,metallogenic regularity and prospecting guideline of different types of deposits in the ore concentration in the southern Hunan Area.

关 键 词：RB-SR同位素 闪锌矿 铅锌多金属矿床 黄沙坪 宝山 湘南 

分 类 号：P611.13[天文地球—矿床学] P597.3[天文地球—地质学]