太行山北段河北阜平县赤瓦屋钼铜矿床辉钼矿Re-Os同位素年龄及其对找矿的指示  

Molybdenite Re-Os isochron age of the Chiwawu Mo-Cu deposit in Fuping County,Hebei Province in northern Taihang Mountains and its prospecting significance

作　　者：张志远 王文浩 丁照月 安跃辉 王志敏 陈志宽 谢桂青 ZHANG Zhiyuan;WANG Wenhao;DING Zhaoyue;AN Yuehui;WANG Zhimin;CHEN Zhikuan;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(北京)科学研究院,北京100083

出　　处：《地质通报》2021年第9期1522-1529,共8页Geological Bulletin of China

基　　金：河北省自然科学基金项目《河北木吉村斑岩型铜钼矿床短波红外光谱蚀变矿物填图及勘查应用研究》(编号:D2020403060);河北省地质矿产勘查开发局项目《太行山北段斑岩型成矿带成矿规律研究及找矿方向研究》(编号:454-0502-JBN-0HDV)。

摘　　要：赤瓦屋斑岩型钼铜矿床是太行山北段斑岩-矽卡岩成矿带内探明的一个中型钼铜矿床,钼铜矿体主要赋存于赤瓦屋岩体内部相的斑状花岗闪长岩中。为厘定赤瓦屋钼铜矿床的成矿时代和成矿物质来源,利用辉钼矿Re-Os同位素定年方法对赤瓦屋钼铜矿床中7件辉钼矿样品进行了成矿年代学测定,获得的模式年龄为129.1~130.6 Ma,年龄加权平均值为129.7±0.7 Ma,对应的等时线年龄为128.7±4.4 Ma,模式年龄和等时线年龄在误差范围内基本一致,指示赤瓦屋钼铜矿床形成于早白垩世。赤瓦屋钼铜矿床辉钼矿样品的Re含量为25.9×10^(-6)~37.1×10^(-6),表明其成矿物质来源于壳幔混源。结合区域年代学资料,认为太行山北段成矿带在134~124 Ma存在一期岩浆热液成矿事件,斑岩铜矿型钼铜矿床的找矿潜力较大。The Chiwawu porphyry Mo-Cu deposit in the northern Taihang Mountains porphyry-skarn metallogenic belt is a medium-sized one discovered in recent years.The Mo-Cu orebodies are mainly hosted within porphyritic granodiorite of internal facies in Chiwawu pluton.In order to determine the age of mineralization and the source of molybdenum,seven molybdenite samples were collected from the Chiwawu Mo-Cu deposit for Re-Os dating.The Re-Os dating yields model ages ranging from129.1 Ma to130.6 Ma,with a weighted mean age of 129.7±0.7 Ma,and obtains an isochron age of 128.7±4.4 Ma.Evidently,model ages are consistent with isochron age within the error ranges,which constrains the ore-forming age of Chiwawu Mo-Cu deposit at the Early Cretaceous.The Re values of molybdenum vary in the range of 25.9×10^(-6)~37.1×10^(-6),indicating that they were derived from mixing of crust and mantle sources.Combined with available chronologic data,it is recognized that a regional magmatic-metallogenic event might exist during the 134~124 Ma in northern Taihang Mountains.The prospecting potentiality of porphyry Cu-Mo deposits is great in this area.

关 键 词：辉钼矿 RE-OS同位素年龄 斑岩钼铜矿床 成岩成矿时代 赤瓦屋 太行山北段 

分 类 号：P618.2[天文地球—矿床学] P597.3[天文地球—地质学]