朱溪矿集区黑云母石英二长斑岩年代学、地球化学特征及其地质意义  

Geochronological and geochemical characteristics of biotite quartz monzonite porphyry in Zhuxi ore concentration area,and its geological implications

作　　者：李艳红 唐炜 陈祺 邹静 饶建锋 欧阳永棚 武彬[3] LI YanHong;TANG Wei;CHEN Qi;ZOU Jing;RAO JianFeng;OUYANG YongPeng;WU Bin(Jiangxi Mineral Resources Guarantee Service Center,Nanchang 330025,Jiangxi,China;No.912 Geological Surveying Team,Bureau of Geology of Jiangxi Province,Yingtan 335001,Jiangxi,China;Nanjing Center,China Geological Survey,Nanjing 210016,Jiangsu,China)

机构地区：[1]江西省矿产资源保障服务中心,江西南昌330025 [2]江西省地质局九一二大队,江西鹰潭335001 [3]中国地质调查局南京地质调查中心,江苏南京210016

出　　处：《矿床地质》2021年第6期1285-1298,共14页Mineral Deposits

基　　金：江西省科学技术厅国家科技奖后备项目培育计划(编号:20203AEI91004);江西省地质勘查基金(编号:20200022、20200013、20150013);国土资源公益性行业科研专项(编号:201411035);江西省地矿局科研(编号:赣地矿字[2017]78号)联合资助。

摘　　要：朱溪矿集区内新发现高Sr/Y型枣林黑云母石英二长斑岩,对其开展系统的地球化学和年代学研究,表明岩石具有高w(SiO_(2))(68.67%~69.27%)、高w(Al_(2)O_(3))(15.78%~16.54%)、高w(K_(2)O)(3.69%~3.88%),为高钾钙碱性、过铝质石英二长斑岩;∑REE为205.21×10^(-6)~213.13×10^(-6),∑LREE/∑HREE=19.10~20.93,轻重稀土元素分馏明显,具弱Eu负异常;Ba、U、K、Pb、Sr正异常,Nb、Ta、P、Ti负异常,具岛弧岩浆特点;较高的w(Sr)(366.05×10^(-6)~474.16×10^(-6))、较低的w(Y)(7.26×10^(-6)~8.89×10^(-6))、w(Yb)(0.62×10^(-6)~0.73×10^(-6))显示出埃达克质岩特征。锆石U-Pb年龄为(157±1)Ma。文章认为枣林黑云母石英二长斑岩受古太平洋板块向大陆斜低角度俯冲的影响,形成于弧岩浆构造环境,源区残留相以角闪岩相为主,次为石榴子石,来源深度较深。朱溪矿集区在160 Ma具备形成含Cu成矿岩浆的构造环境及岩浆岩条件,具有找寻斑岩型铜矿的潜力。High Sr/Y-type biotite quartz monzonite porphyry is newly discovered at Zaolin in the Zhuxi ore concentration area,Jiangxi Province.The systematic geochemical and chronological studies indicate that the rock has high w(Si O_(2))(68.67%~69.27%),w(Al_(2)O_(3))(15.78%~16.54%) and w(K_(2)O)(3.69%~3.88%) values,which can be classified as high-potassium calc-alkaline and peraluminous quartz monzonitic porphyry.∑REE is 205.21×10^(-6)~213.13×10^(-6),∑LREE/∑HREE=19.10~20.93.The fractionation of light and heavy rare earth elements are obvious,with weak negative Eu anomaly;positive Ba,U,K,Pb,Sr anomalies and negative Nb,Ta,P,Ti anomalies having the characteristics of island arc magma.Higher Sr (366.05×10^(-6)~474.16×10^(-6)),lower Y (7.26×10^(-6)~8.89×10^(-6)) and Yb (0.62×10^(-6)~0.73×10^(-6)) contents show the characteristics of adakitic rock.Zircon U-Pb age is (157±1) Ma.This paper believes that the biotite quartz monzonite porphyry was formed in an arc magmatic tectonic environment affected by the low-angle westward subduction of the ancient Pacific plate to the continental plate.The residual facies in the source area are dominated by amphibolite facies,secondly garnet amphibolite.The~160 Ma period in the Zhuxi ore concentration area has favourable tectonic setting and magmatic rock conditions for the formation of Cu-bearing magma,and the area has good potential to explore for porphyry copper deposits.

关 键 词：地球化学 黑云母石英二长斑岩 锆石U-PB年龄 找矿潜力 朱溪矿集区 

分 类 号：P588.13[天文地球—岩石学] P597[天文地球—地质学]