河北涞源大湾锌钼矿床锆石U-Pb和辉钼矿Re-Os年龄及其地质意义  

Zircon U-Pb and molybdenite Re-Os dating of Dawan Zn-Mo deposit in Laiyuan County of Hebei Province and its geological significance

作　　者：田林 张志远 王志敏 丁照月 李天琦 卢鸿鹏 安跃辉 胡华斌 谢桂青[3] TIAN Lin;ZHANG ZhiYuan;WANG ZhiMin;DING ZhaoYue;LI TianQi;LU HongPeng;AN YueHui;HU HuaBin;XIE GuiQing(Hebei Key Laboratory of Strategic Critical Mineral Resources,Hebei GEO University,Shijiazhuang 050031,Hebei,China;Hebei Geological Engineering Exploration Institute,Baoding 071051,Hebei,China;Institute of Earth Sciences,China University of Geosciences,Beijing 100083,China)

机构地区：[1]河北地质大学河北省战略性关键矿产资源重点实验室,河北石家庄050031 [2]河北省地质工程勘查院,河北保定071051 [3]中国地质大学科学研究院,北京100083

出　　处：《矿床地质》2021年第6期1214-1229,共16页Mineral Deposits

基　　金：河北省自然科学基金(编号:D2020403060);国家自然科学基金(编号:41925011);河北省地质矿产勘查开发局项目(编号:454-0502-JBN 0HDV)联合资助。

摘　　要：大湾斑岩-矽卡岩型锌钼矿床地处太行山北段成矿带中,是该段重要的金属矿床之一。五台群板峪口组和长城系高于庄组为主要赋矿围岩,锌钼矿体主要赋存在流纹斑岩体内及斑岩与围岩接触部位。文章对大湾矿床内2件赋矿流纹斑岩进行LA-ICP-MS锆石U-Pb年代测定,获得206Pb/238U年龄加权平均值分别为(137.1±0.9)Ma(MSWD=0.56,n=24)和(136.8±1.2)Ma(MSWD=0.40,n=22);对矿区4件辉钼矿样品进行Re-Os定年,得到加权平均年龄为(136.5±1.0)Ma,等时线年龄为(136.1±2.3)Ma,在误差范围内成岩成矿时代一致,显示大湾锌钼矿床形成于早白垩世。大湾矿床中辉钼矿的w(Re)为5.816~16.484μg/g,反映了矿床成矿物质来源具有壳幔混合特征。区内流纹斑岩和蚀变体系为进一步找矿勘查的有利标志。The Dawan porphyry-skarn Zn-Mo deposit is one of important metal deposits in the northern Taihang Mountain metallogenic belt.The Banyukou Formation of Wutai Group and the Gaoyuzhuang Formation of Changcheng System are the main country rocks of the mineralization related intrusive rocks.The Zn-Mo ore body mainly occurs in rhyolite porphyry and the contact zones of rhyolite porphyry and its country rocks.In this paper,the LA-ICP-MS zircon U-Pb analysis of the two rhyolite porphyry samples from the Dawan deposit yielded the weighted 206Pb/238U mean ages as(137.1±0.9)Ma(MSWD=0.56,n=24) and(136.8±1.2)Ma(MSWD=0.40,n=22),respectively.Re-Os dating of four molybdenite samples show that the weighted mean age and isochron age are(136.5±1.0)Ma and(136.1±2.3)Ma,respectively,which indicates that the Dawan deposit was formed in the Early Cretaceous.The w(Re) of molybdenite vary in the range of 5.816~16.484 μg/g,showing that they were derived from mixed crust and mantle sources.Rhyolite porphyry and porphyry-related alteration system in the Dawan deposit are the useful indication for prospecting and exploration of the same style mineralization in the region.

关 键 词：地球化学 锆石U-PB测年 辉钼矿Re-Os测年 流纹斑岩 大湾锌钼矿床 太行山北段 

分 类 号：P618.43[天文地球—矿床学] P618.65[天文地球—地质学]