相山南部花岗斑岩黑云母及绿泥石矿物化学特征及地质意义  

Mineral Characteristics of Biotite and Chlorites from Granite Porphyries in the Southern Xiangshan and Their Geological Significance

作　　者：刘龙[1] 张树明[1,2] 张鑫[1,2] 夏寅初 LIU Long;ZHANG Shu-ming;ZHANG Xin;XIA Yin-chu(State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, China;Fundamental Science on Radioactive Geology and Exploration Technology Laboratory, East China Institute of Technology, Nanchang 330013, China)

机构地区：[1]东华理工大学核资源与环境国家重点实验室,南昌330013 [2]东华理工大学放射性地质与勘探技术国防重点学科实验室,南昌330013

出　　处：《科学技术与工程》2022年第8期3029-3037,共9页Science Technology and Engineering

基　　金：国家自然科学基金(41862006);江西省研究生创新专项基金(YC2020-B159)。

摘　　要：黑云母及绿泥石成分特征能够分别示踪寄主岩石的成岩条件和成矿条件,为了探究相山南部花岗斑岩成岩成矿条件,对黑云母和蚀变绿泥石进行电子探针分析。结果表明:黑云母类型为铁质黑云母;花岗斑岩岩浆的温度和压力分别为541~725℃、175~395 MPa,侵位深度6.4~14.4 km;黑云母氧逸度位于NNO(Ni-NiO)缓冲剂附近,指示具有较高氧逸度;岩石成因类型为A型花岗岩,形成于板内拉张构造环境,物质来源于上地壳且逐渐受到幔源的影响;绿泥石为蠕绿泥石和铁镁绿泥石,属于富铁绿泥石,形成于还原环境。绿泥石形成温度249.7~272.2℃,属于中温热液作用范围。绿泥石化为铀成矿提供了铀源和吸附空间。Biotite and chlorite can be indicators for diagenetic and metallogenic conditions of host rocks respectively.To explore the diagenetic and metallogenic conditions of the granite porphyry in the south of Xiangshan,the biotite and altered chlorite were analyzed by electron probe.The results show that the biotite type is iron biotite.The temperature and pressure of the granite-porphyry magma are 541~725℃,175~395 MPa,respectively,and the emplacement depth are 6.4~14.4 km.The oxygen fugacity of biota is located near NNO(Ni-NiO)buffer,indicating a high oxygen fugacity.The petrogenesis type is A-type granite,which is formed in the intraplate extensional tectonic environment.Material sources come from the upper crust and are gradually influenced by the mantle source.Chlorite is vermicular chlorite and mafic chlorite,which are rich in iron and formed in reducing environment.The formation temperature of chlorite is 249.7~272.2℃,which belongs to the range of medium temperature hydrothermal action.Chloritization provides uranium source and absorption space for uranium mineralization.

关 键 词：黑云母 绿泥石 矿物化学特征 花岗斑岩 成岩成矿 相山 

分 类 号：P575[天文地球—矿物学] P585.12[天文地球—地质学]