河南栾川石宝沟Mo矿床岩体年龄及氧逸度的成矿意义  

Pluton age and minerallogenic significance of oxygen fugacity of Shibaogou Mo deposit in Luanchuan,Henan

作　　者：杨正良 任龙 邓明国[1] 张振杰 贾祯 杨佳飞 杨正香 YANG Zhengliang;REN Long;DENG Mingguo;ZHANG Zhenjie;JIA Zhen;YANG Jiafei;YANG Zhengxiang(Faculty of Land Resources Engineering,Kunming University of Science and Technology,Kunming 650093,China;School of Earth Science and Resources,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]昆明理工大学国土资源工程学院,昆明650093 [2]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《有色金属（矿山部分）》2023年第5期134-145,共12页NONFERROUS METALS(Mining Section）

基　　金：国家自然科学基金资助项目(41762009,42050103)。

摘　　要：石宝沟是栾川矿集区新发现的大型斑岩-矽卡岩Mo(W)矿床,其成矿岩体年龄尚存在较大争议,前人对石宝沟岩体岩浆氧逸度的研究也相对薄弱,岩浆氧逸度是表征岩石物理化学性质的重要参数,对岩浆热液成矿起到显著的控制作用。为了进一步约束石宝沟岩体年龄和探讨其岩浆氧逸度的成矿意义,运用LA-ICP-MS方法测定石宝沟岩体锆石U-Pb年龄,并用锆石微量元素计算岩浆氧逸度和温度。获得石宝沟岩体似斑状黑云母二长花岗岩、中细粒黑云母二长花岗岩和石英斑岩的年龄分别为(147.4±0.8)Ma、(147.0±1.0)Ma和(146.9±1.1)Ma;温度为692、718和737℃;氧逸度(log fO_(2))分别为-16.16、-14.40和-12.77;相对氧逸度(△FMQ)分别为1.25、3.35、3.56,表明石宝沟岩体具有较高的温度和岩浆氧逸度,有利于斑岩Mo矿床的形成。从早期到晚期,温度和氧逸度均有增加的趋势,暗示后期侵入的石英斑岩为重要的找矿标志。The Shibaogou deposit located in the Luanchuan ore concentration area,is a large-scale porphyry-skarn Mo(W)deposit discovered in recent years.However,the dating of ore-forming pluton is still controversial.Meanwhile,the studying of magmatic oxygen fugacity,the important physical and chemical parameters of porphyry deposit,is also not very satisfactory.In order to constrain the age of the Shibaogou pluton and the metallogenic significance of the magmatic oxygen fugacity,the zircon U-Pb dating and trace element composition were detected via LA-ICP-MS method,and the oxygen fugacity and temperature were also calculated.The results show that the ages of porphyritic biotite monzonitic granite,medium-fine grained biotite monzonitic granite,and quartz porphyry in the mine were(147.4±0.8)Ma,(147.0±1.0)Ma and(146.9±1.1)Ma,respectively.The temperatures were 692℃,718℃and 737℃.The oxygen fugacity(log f O_(2))were-16.16,-14.40,and-12.77,with the relative oxygen fugacity(△FMQ)of 1.25,3.35,and 3.56,respectively.These indicated that Shibaogou pluton had the characteristics of high temperature and oxygen fugacity,conducive to the formation of porphyry Mo deposits.With evolution of magma,the temperature and oxygen fugacity increased,thus quartz porphyry intruded in the late stage may be an important criteria in ore prospecting.

关 键 词：石宝沟矿床 锆石U-PB年龄 岩浆氧逸度 锆石Ti温度计 栾川矿集区 

分 类 号：P595[天文地球—地球化学] P597[天文地球—地质学]