赣南盘古山钨矿床锆石U-Pb和辉钼矿Re-Os年龄及其意义  

Zircon U-Pb and Molybdenite Re-Os Geochronology of the Pangushan Tungsten Deposit in South Jiangxi Province and Its Significance

作　　者：方贵聪[1,2] 陈毓川[1] 陈郑辉[2] 曾载淋[3] 张永忠[3] 童启荃 孙杰 黄鸿新[5] 郭娜欣[1] 

机构地区：[1]中国地质科学院,北京100037 [2]中国地质科学院矿产资源研究所,国土资源部成矿作用与资源评价重点实验室,北京100037 [3]江西省地质矿产勘查开发局赣南地质调查大队,江西赣州341000 [4]江西盘古山钨业有限公司,江西于都342311 [5]长江大学,湖北武汉430100

出　　处：《地球学报》2014年第1期76-84,共9页Acta Geoscientica Sinica

基　　金：国家深部探测技术与实验研究专项(SinoProbe-03-03);国土资源部公益性行业科研专项(编号:201311162;201011048);国土资源部成矿作用与资源评价重点实验室开放研究项目"南岭科学钻(SP-NLSD-2)花岗岩-云英岩化带-钨矿石英脉:地球化学特征及岩浆-流体演化"(编号:2013091611);中国地质调查局地质调查项目(编号:1212010633903)联合资助

摘　　要：盘古山钨矿是一个历史悠久、闻名国内外的大型矿床，为了厘定其岩浆活动及成矿作用时代，进而认识成岩与成矿关系、岩体内带与外带矿化关系及成岩成矿动力学背景，本研究采用LA-ICP-MS锆石U-Pb和ICP-MS辉钼矿Re-Os分析法分别对南岭2000m科学钻探（SP-NLSD-2）所揭露的隐伏花岗岩体及其内带矿化石英脉进行了年龄测定。结果表明，隐伏花岗岩体形成于（161．7±1．6）Ma，内带矿化石英脉年龄为（155.3±2．8）Ma，均形成于中一晚侏罗世。盘古山钨矿床花岗岩浆活动与成矿作用的时代在误差范围内基本一致，矿化发育于岩体内外接触带，在空间上关系密切，并表现出花岗岩体→长石石英脉→石英脉的渐变演化关系，结合前人研究成果表明，矿化石英脉是花岗岩浆分异演化晚期的产物。岩体内带石英脉与外带石英脉的形成年龄吻合较好，形成于同一成矿作用。盘古山钨矿床及其隐伏花岗岩体均形成于165-150Ma华南岩石圈伸展-岩体侵位-大规模成矿的动力学环境。The Pangushan tungsten deposit is a well-known old and large ore deposit which has attracted many researchers and exploration geologists both in China and abroad. In order to determine the ages of magmatism and mineralization in the deposit and thus to gain insights into the relationship between magmatic process and tungsten mineralization, the association of endocontact mineralization with exocontact mineralization as well as their geodynamic setting, the authors conducted LA-ICP-MS zircon U-Pb and ICP-MS molybdenite Re-Os isotopic measurement of Pangushan concealed granite and its endocontact-mineralized quartz veins discovered by 2000 m Nanling Scientific Drilling （SP-NLSD-2）. The results indicate that the weighted average ages of zircon ^206pb/^238U ages for Pangushan granite and of molybdenite Re-Os isotopic model ages for the quartz veins are （161.7±1.6） Ma and （155.3±2.8） Ma, respectively, both subordinate to Mid-late Jurassic. The determinations, together with previous data, suggest that the mineralized quartz veins were produced by terminal magma evolution, which is supported by the fact that the ages of mineralization and magmatism were basically in accordance, the mineralization all occurred spatially at the inner- and outer-contacts of the granite, and the gradient relationship of granite→feldspar quartz vein→quartz vein was detected in the deposit. Endocontact and exocontact ore-bearing quartz veins were both produced by the same mineralization. Geodynamically, the Pangushan tungsten deposit is one of many important tungsten-polymetallic deposits formed from 165 Ma to 150 Ma associated with large-scale lithospheric extension in South China.

关 键 词：地质年代学 U—Pb Re—Os 钨矿床 盘古山 赣南 南岭 

分 类 号：P597[天文地球—地球化学] P618.67[天文地球—地质学]