赣东北茶坑花岗斑岩锆石U-Pb年代学、地球化学特征及地质意义  

Zircon U-Pb geochronology,geochemical characteristics and geological significance of the Chakeng granite porphyry,northeast Jiangxi Province

作　　者：陆凡 张勇[2] 张雪辉[2] 莫子奋 吕劲松[2] 武彬[2] LU Fan;ZHANG Yong;ZHANG Xuehui;MO Zifen;LYU Jinsong;WU Bin(The Sixth Geological Brigade of Jiangxi Geological Bureau,Yingtan 335001,Jiangxi,China;Nanjing Center,China Geological Survey,Nanjing 210016,Jiangsu,China)

机构地区：[1]江西省地质局第六地质大队,江西鹰潭335001 [2]中国地质调查局南京地质调查中心,江苏南京210016

出　　处：《华东地质》2023年第1期39-50,共12页East China Geology

基　　金：国家重点研发项目“武夷德化—尤溪—永泰矿集区三维综合探测与深部成矿预测(编号:2016YFC0600210)”;中国地质调查局“钦杭成矿带武宁—平江地区钨铜多金属矿地质调查(编号:DD20190153)”项目联合资助。

摘　　要：赣东北茶坑花岗斑岩及围岩中发现了白钨矿化。为了进一步查明钨矿化与花岗斑岩的关系及其成矿潜力,对花岗斑岩开展了锆石U-Pb年代学、岩相学及地球化学研究。结果表明:茶坑花岗斑岩的形成年龄为153~152 Ma;具有高硅(SiO 2含量为74.62%~76.09%)、富碱(Na 2O+K 2O含量为7.14%~8.55%)、富钾(K 2O含量为4.95%~5.69%)、强过铝质(A/CNK为1.17~1.39,平均值为1.3)的特征;微量元素相对富集Rb、U、K,亏损Ba、Sr、P、Ti;稀土元素总含量为(62.52~75.13)×10^(-6),(La/Yb)N=3.73~12.16,平均值为7.81,轻、重稀土元素分馏明显,且相对富集轻稀土,具有中等程度的Eu负异常(δEu为0.55~0.82)。茶坑地区花岗斑岩的W含量为(8.80~160)×10^(-6),平均值为51.16×10^(-6),是华南花岗岩W平均含量的15倍,表明该地区花岗斑岩具有形成斑岩型-石英脉型钨矿的潜力。The scheelite mineralization was found in the Chakeng granite porphyry and its surrounding rocks in northeastern Jiangxi Province.In order to ascertain the relationship between the tungsten mineralization and granite porphyry and pursue its metallogenic potential,the zircon U-Pb isotopic dating,geochemical and petrographic studies of granite porphyry were carried out.The results show that the Chakeng granite porphyry is 152~153 Ma in age,characterized with high silicon(content of SiO 2 is 74.62%~76.09%),rich alkali(content of Na 2O+K 2O is 7.14%~8.55%)and kalium(content of K 2O is 4.95%~5.69%),as well as strongly peraluminous(A/CNK=1.17~1.39,averagely 1.3);the trace elements are relatively enriched in Rb,U,K,and deficient in Ba,Sr,P,Ti;The total content of rare earths is(62.52~75.13)×10^(-6),and(La/Yb)N=3.73~12.16,with an average value of 7.81.The fractional distillation of light and heavy rare earth elements is obvious,and the light rare earth elements are relatively enriched,with moderate negative Eu anomaly(δEu is 0.55~0.82).The W content in the Chakeng granite porphyries is(8.80~160)×10^(-6),with an average value of 51.16×10^(-6),15 times of the average tungsten content of the granites in South China,indicating that the granite porphyries in the Chakeng area have metallogenic potential of porphyry-quartz vein-type tungsten deposit.

关 键 词：赣东北茶坑 花岗斑岩 锆石U-PB年龄 岩石地球化学 白钨矿化 

分 类 号：P611[天文地球—矿床学] P618.67[天文地球—地质学]