江西通江岭铜(钨)矿床石榴子石和锆石LA-ICP-MS原位U-Pb定年及其地质意义  

In-situ LA-ICP-MS U-Pb dating of garnet and zircon from Tongjiangling copper(tungsten)deposit in Jiangxi Province and its geological significance

作　　者：王海 付海平 李永胜[3] 钟福军 王颖 吉鸿杰 徐林 胡朗明 杨世彪 WANG Hai;FU Haiping;LI Yongsheng;ZHONG Fujun WANG Ying;JI Hongjie;XU Lin;HU Langming;YANG Shibiao(East China University of Technology,State Key Laboratory of Nuclear Resources and Environment,Nanchang,Jiangxi,330013,China;Geophysical and Geochemical Exploration Party,Jiangxi Bureau of Geology and Mineral Exploration and Development,Nanchang,Jiangxi 330200,China;Development Research Center of China Geological Survey,Beijing 100037,China;Institute of Geomechanics,China Academy of Geological Sciences,Beijing 100081,China;Sichuan Huili Zinc&Piumbum Co.,Huili,Sichuan 615105,China)

机构地区：[1]东华理工大学,核资源与环境国家重点实验室,江西南昌330013 [2]江西省地质局物化探大队,江西南昌330200 [3]中国地质调查局发展研究中心,北京100037 [4]中国地质科学院地质力学研究所,北京100081 [5]四川会理铅锌股份有限公司,四川会理615105

出　　处：《地质学报》2023年第7期2281-2292,共12页Acta Geologica Sinica

基　　金：核资源与环境国家重点实验室自主基金项目(编号2020Z16,Z1919);国家自然科学基金青年基金项目(编号42103015)联合资助的成果。

摘　　要：长江中下游发育众多斑岩-矽卡岩型多金属矿床,由于缺乏精确的成矿时代数据,制约了对这些矿床成因和动力学背景的认识。通江岭铜钨矿位于长江中下游Fe-Cu-Au成矿带九瑞矿集区北侧,为近期新发现的斑岩-矽卡岩型矿床,经济矿物主要为黄铜矿和少量白钨矿,呈细脉状和浸染状产于斑岩与矽卡岩中。本文对赋矿岩体花岗闪长斑岩中的锆石和含矿矽卡岩中石榴子石进行LA-ICP-MS U-Pb同位素精确定年,锆石^(206)Pb/^(238)U的加权年龄为146.3±0.9 Ma(2σ,MSWD=1.13,n=33),石榴子石^(206)Pb/^(238)U加权平均年龄为142.9±2.1 Ma(2σ,MSWD=1.2,n=17),表明矽卡岩和岩体形成时代相近,成岩成矿作用过程连续。通江岭铜钨矿成岩、成矿时代与九瑞矿集区典型矿床成岩、成矿时代一致,同时也与长江中下游地区铜陵、安庆和部分鄂东南的典型铜多金属矿床成岩、成矿时代基本一致,均属于长江中下游成矿带晚侏罗世—早白垩世多金属成矿作用事件的产物。Manyporphyry-skarn type polymetallic deposits are developed in Middle and Lower Yangtze River Valley metallogenic belt.However,the lack of accurate mineralization chronologic data severely restricts in-depth understanding of the genesis and geodynamic setting of these deposits.The Tongjiangling Cu-W deposit is a newly discovered porphyry-skarn deposit,which is located in the north part of the Jiujiang-Ruichang ore concentration area of the Middle and Lower Yangtze River metallogenic belt.Chalcopyrite and scheelite are the common metal minerals,occurring as veins and disseminations in the granodiorite porphyry and skarn.In this paper,the authors have undertaken LA-ICP-MS U-Pb dating of garnet in ore-bearing skarn and zircon in granodiorite to define the mineralization age of this deposit.The U-Pb LA-ICP-MS dating of zircons from Tongjiangling granite porphyry yielded an age of 146.3±0.9 Ma(2σ,MSWD=1.13,n=33).LA-ICP-MS U-Pb dating of garnets from skarn yield weighted mean^(206)Pb/^(238)U age of 142.9±2.1 Ma(2σ,MSWD=1.2,n=17),indicating consistent diagenetic and metallogenic ages and their close genetic relationship.These data indicate that the ages of intrusion and the orebody from the Tongjiangling deposit are almost identical with other typical magmatic intrusions and deposits in the Jiujiang-Ruichang metallogenic belt,and Tongling,Anqing and part of southeast Hubei in the Middle and Lower Yangtze River metallogenic belt.They belong to part of the Late Jurassic-Early Cretaceous polymetallic metallogenic events in the Middle and Lower Yangtze River metallogenic belt.

关 键 词：通江岭铜钨矿 锆石 石榴子石 U-PB定年 九瑞矿集区 成岩成矿年龄 

分 类 号：P618.41[天文地球—矿床学] P618.67[天文地球—地质学]