江西武宁县东坪钨矿床中与成矿有关的岩浆岩年代学、地球化学及岩石成因  

Geochrology, Geochemistry and Petrogenesis of Ore-Related Granite in the Dongping Tungsten Deposit in Wuning County, Jiangxi Province

作　　者：胡正华[1,2,3] 楼法生 李永明[1] 李吉明[1] 王先广[3] 陈建平 曾庆权[1] 吴师金[1] 聂龙敏[1] 龚良信[1] 文亮先 刘高峰 李倩[1] 余希[3] Hu Zhenghua;Lou Fasheng;Li Yongming;Li Jiming;Wang Xianguang;Chen Jianping;Zeng Qinquan;Wu Shijin;Nie Longmin;Gong Liangxin;Wen Liangxian;Liu Gaofeng;Li Qian;Yu Xi(Jiangxi institute of Geological Survey,Nanchang 330000,China;School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China;Jiangxi Geological Prospecting Fund Management Center,Nanchang 330030,China)

机构地区：[1]江西省地质调查研究院,江西南昌330000 [2]中国地质大学地球科学与资源学院,北京100083 [3]江西省地质勘查基金管理中心,江西南昌330030

出　　处：《地球科学》2018年第A01期243-263,共21页Earth Science

基　　金：江西省人力资源和社会保障厅博士后科研项目(No.2016KY12);江西省地勘基金项目(No.20150008);国土资源部公益性行业专项(No.201411035);中央地勘基金项目(No.2013360010)

摘　　要：江西省东坪钨矿床位于江南造山带东段,是中国新发现的超大型"五层楼式"石英脉型黑钨矿矿床.为探讨东坪钨矿床的成矿岩浆岩形成时代、来源及其构造背景,在详实的野外地质调查基础上对东坪成矿黑云母花岗岩进行了详细的锆石U-Pb年代学、主量、微量元素地球化学以及Sr-Nd同位素研究.LA-ICP-MS锆石U-Pb定年测得东坪黑云母花岗岩结晶年龄为132.9±1.4 Ma (MSWD=0.40,n=25);岩石地球化学特征表明黑云母花岗岩为高硅高钾钙碱性过铝质高分异S型花岗岩,ω(SiO_2)为73.19%~75.21%、ω(Na_2O+K_2O)为6.84%~8.45%、A/CNK为1.21~1.44,亏损Sr、Ba、Ti,富集Rb、Th、U、P;∑REE为43.52~60.88μg/g,轻稀土富集,重稀土亏损,强负铕异常(Eu/Eu*=0.21~0.41),稀土配分曲线呈右倾深"V"型.黑云母花岗岩(87Sr/86Sr)?值介于0.715 1~0.725 8,εNd(t)值介于-3.28^-5.99,两阶段模式年龄TDM2为1.57~1.84 Ga(t=132.9 Ma).综合分析认为,东坪成矿岩浆岩来源于富泥质岩石熔融,其源区岩石很可能是华南中元代古老基底物质的再循环,形成于太平洋板块俯冲引起的陆内"伸展-拉张"动力学背景.The Dongping tungsten deposit,located in the eastern section of Jiangnan orogenic belt in Jiangxi Province, which is a newly discovered giant＂five-story＂quartz vein type wolframite ore deposit. In order to studying the metallogenic magmatic rock of the age, source and tectonic background of the Dongping tungsten deposit, this paper has carried out detailed zircon U-Pb chronology, major-trace element geochemistry,and Sr-Nd isotope studies of the Dongping metallogenic biotite granite. LA-ICP-MS zircon U-Pb dating results demonstrate the age of Dongping biotite granite is 132.9±1.4 Ma（MSWD=0.40, n=25）. The biotite granite with high-silicon（73.19%~75.21%）, high-potassium（6.84%~8.45%）,is calc-alkaline, prealuminous（1.21~1.44）, and belongs to highly differentiated S-type granites. This biotite granite is depleted in Sr, Ba,and Ti,and enriched in Rb, Th, U, and P; The ΣREE concentration is in the range of 43.52 to 60.88 μg/g in light rare earth depletion of heavy rare earth,and strong Europium anomaly（Eu/Eu＊=0.21~0.41）. The（87 Sr/86 Sr）of biotite granite samples are between 0.715 1 and 0.725 8, the εNd（t） is from-3.28 to-5.99, and the the two-stage model age TDM2 is from 1.57 to 1.84 Ga（t=132.9 Ma）. According to the comprehensive analysis that the Dongping metallogenic magmatic rock may origin from re-melted mudstone.which is part of the Mesozoic ancient basement materials in the South China, under the continental extension background caused by the Pacific plate subduction. The gneiss type of Dongping tungsten deposit is the high temperature hydrothermal type after magmatic period event.

关 键 词：锆石U-PB 地球化学 黑云母花岗岩 钨矿床 东坪 赣北 

分 类 号：P611[天文地球—矿床学]