北武夷王坞矿区花斑岩与钼矿的关系:来自锆石U-Pb和辉钼矿Re-Os定年的证据  

Relationship Between Granophyre and Molybdenum Ore of Wangwu Mining District in North Wuyi Region: Evidences from Zircon U-Pb and Molybdenite Re-Os Dating

作　　者：魏娟娟[1,2] 狄永军[1] 魏英文[3] 张达[1] 罗平[3] 罗国辉[3] 秦晓峰[1] 董越[1] 杨秋[1] 陈杰[1] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]上饶市广丰区国土资源局,江西上饶334600 [3]江西省地质矿产勘查开发局赣东北大队,江西上饶334000

出　　处：《现代地质》2016年第1期59-68,共10页Geoscience

基　　金：中国地质调查局项目(1212011220557)

摘　　要：王坞钼铜矿床是北武夷地区近年来发现并正在勘查的具大型规模以上潜力的矿床。在矿床地质特征研究的基础上,通过锆石LA-ICP-MS U-Pb法测年,获得矿区中与钼矿体在空间上关系密切的花斑岩脉的加权平均年龄为(127.5±1.8)Ma(MSWD=1.4),说明其形成于早白垩世;通过辉钼矿Re-Os法测年,获得辉钼矿Re-Os等时线年龄为(153.7±3.2)Ma(MSWD=3.9),说明钼矿形成于晚侏罗世。因此,花斑岩脉的成岩时代远远晚于钼矿成矿时代,表明两者无成因联系。通过对比邻区矿床成矿特征并结合现有资料分析,推断王坞矿区成钼岩体为酸性花岗斑岩或黑云母花岗岩,位于南东方向深部,深部找矿前景较好。北武夷地区中生代主要成钼时期为晚侏罗世早期(155 Ma±)和早白垩世早期(135 Ma±),该时期钼铜矿的形成与古太平洋板块俯冲形成的弧岩浆活动有关。The Wangwu Mo-Cu deposit is one that has been explorating and has the potential of large or superlarge scale in recent years in North Wuyi region. Based on the study of geological feature,with LA-ICP-MS zircon U-Pb dating,the granophyre vein weighted mean age is（ 127. 5 ± 1. 8） Ma（ MSWD = 1. 4）. It is shown that the deposit formed in Early Cretaceous Epoch. Using molybdenite Re-Os dating,the isochron age is（ 153. 7 ± 3. 2） Ma（ MSWD = 3. 9）. It indicates that metallogenesis of Mo occurred in Late Jurassic Epoch. The diagenesis age of granophyre vein is much later than that of Mo deposit,which shows that there is no relationship between them. Comparing the neighbor deposit mineralization feature and analyzing the existed information,it infers that the rock of molybdenum is acidic granite porphyry or biotite granite,which is located in the deeparea of southeastern part of the ore district. The major metallogenesis age of Mo is Early-Late Jurassic Epoch（ 155 Ma ±） and Early Cretaceous Epoch（ 135 Ma ±） in North Wuyi area. During this period,the formation of Mo and Cu deposits are related to magmation caused by paleo-pacific plate subducting.

关 键 词：RE-OS定年 锆石U-PB定年 辉钼矿 花斑岩 王坞 北武夷 

分 类 号：P588.1[天文地球—岩石学] P618.2[天文地球—地质学]