景德镇朱溪钨(铜)矿床花岗斑岩的锆石U-Pb年龄、地球化学特征及其与成矿关系探讨  

LA-ICP-MS Zircon U-Pb Age,Geochemical Features and Relations to the W—Cu Mineralization of Granitic Porphyry in Zhuxi Skarn Deposit,Jingdezhen,Jiangxi

作　　者：李岩[1,2] 潘小菲[1] 赵苗[1,2] 陈国华[3] 张天福[1,2] 刘茜[1,2] 张诚[3] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质大学(北京),北京100083 [3]江西省地质矿产勘查开发局912大队,江西鹰潭335001

出　　处：《地质论评》2014年第3期693-708,共16页Geological Review

基　　金：国家科技支撑计划项目(编号2011BAB04B02);国家自然科学基金重点项目(编号40730419)的成果

摘　　要：江西省景德镇朱溪钨（铜）多金属矿是近年新发现的一个矽卡岩型矿床,其研究基础薄弱.为了确定与该矿床形成密切相关的花岗斑岩的侵位时代、岩石成因,以及与矿床的内在关系.文章对矿区钻孔中发育的花岗斑岩岩株进行了岩相学、地球化学及锆石LA-ICP-MS U-Pb年代学研究.研究的结果表明,花岗斑岩的侵位年龄为150Ma左右;岩石富硅[SiO2平均为76.57％]、富碱[（Na2O＋K2O）平均为5.43％]、A/CNK均大于1.0,属过铝质岩石;富集轻稀土,亏损重稀土,且具有明显的负铕异常（δEu =0.18 ～0.21）;富集Th、U、Rb等大离子亲石元素;亏损Nb、Ti等高场强元素;与（华南）陆壳改造系列花岗岩（S型花岗岩）的地球化学特征相类似;锆石εHf（f）为-16.5～0.6;两阶段Hf模式年龄主要集中在1.58 ～2.58Ga,也表明朱溪花岗斑岩是由古元古代地壳组分熔融产生,且有少量地幔物质参与.初步探讨了朱溪大规模钨（铜）矿化与花岗斑岩的密切关系,认为花岗斑岩可能为其提供了成矿物质及能量来源.The Zhuxi W--Cu polymetallic ore deposit, located in the Jingdezhen of the Central Jiangnan belt in Jiangxi Province, is a skarn-type ore deposit in the Late Paleozoic carbonate basin on the Neoproterozoic basement. LA-ICP-MS Zircon U-Pb age, whole-rock major and trace elements of granite porphyry of this deposit were analyzed to discuss the emplacement ages and petrogenesis of this intrusion and the mineralization age of ore deposits. The LA-ICP-MS zircon U-Pb dating of granite porphyry shows that the crystallization age is about 150Ma. The major element analyses show that the rock is enriched in silica and alkali （with the average SiO2 76.57% , average（ Na2O ＋ K2O） 5.43% ） , A/CNK 〉 1. 0, and can be classified as peraluminous. The rock is enriched in LREE and LILE, and depleted in HREE and HFSE in the primitive mantle normalized multi-element diagram, exhibiting obvious negative Eu anomalies and showing some characteristics of S-type granites in South China Low εHf（t） values -16.5 -0. 6 with Hf model ages 1.58 -2.58Ga indicate that the Zhuxi granite porphyry was derived from partial melting of the Paleoproterozoic crust rocks and mantle materials could be involved in the magmatic sources. The large scale mineralization of the Zhuxi W—Cu polymetallic ore deposit are closely related to granite porphyry in the Zhuxi and may be contribute the mineralization material and force.

关 键 词：锆石LA-ICP-MS U-Pb定年 地球化学特征 锆石HF同位素 花岗斑岩 朱溪钨(铜)多金属矿 江西景德镇 

分 类 号：P618.67[天文地球—矿床学] P597.3[天文地球—地质学]