云南因民铁铜矿区次火山杂岩中黑云母和绿泥石矿物化学特征与成矿指示  

Mineralogy and Geochemistry of Biotite and Chlorite in Subvolcanic Complex Rock from Yinmin Iron-Copper Mining Area in Yunnan Province, China and Their Mineralization

作　　者：鲁佳[1,2] 方维萱[1,2,3] 王同荣[2] 孙紫坚 郭玉乾[3] 宋丽红[3] LU Jia;FANG Wei-xuan;WANG Tong-rong;SUN Zi-jian;GUO Yu-qian;SONG Li-hong(Kunming University of Science and Technology, Kunming 650093, China;Beijing Institute of Geology for Mineral Resources, Beijing 100012, China;China Non-Ferrous Metals Resource Geological Survey, Beijing 100012, China)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093 [2]北京矿产地质研究院,北京100012 [3]有色金属矿产地质调查中心,北京100012

出　　处：《矿物学报》2017年第5期576-587,共12页Acta Mineralogica Sinica

基　　金：科技部转制科研院专项资金项目(2011EG115022;2014EG115019)

摘　　要：云南因民铁铜矿区次火山杂岩主要由铁质熔岩、辉绿岩、辉长辉绿岩、火山集块岩、火山角砾岩、热液角砾岩等组成,岩相分带明显,热液蚀变与矿化关系密切。通过对次火山杂岩中不同岩相的黑云母和绿泥石电子探针结果分析得出,黑云母为镁质黑云母,大多数为再平衡黑云母,形成温度为505~590℃,lgf(O2)为-12.4^-5.25,压力为116~226 MPa,推测成岩深度为4.27~8.37 km,属于高温强氧化环境;绿泥石为密绿泥石、蠕绿泥石、透绿泥石、叶绿泥石,形成温度为170~235℃,lgf(O2)为-51.93^-43.70,lgf(S2)为-13.34^-2.50,属于中低温强还原环境。矿物产状、矿物组合与矿物中主要阳离子关系显示,两种矿物均具有多期多源性的特征。黑云母化蚀变代表铁矿的主成矿期,绿泥石化蚀变代表铜矿的主成矿期;多期次构造-岩浆-热事件形成了高-中低温的碱性强还原流体,叠加改造富集铁铜矿床,揭示了本区次火山杂岩是铁铜矿床稳定持续性成矿元素的供给系统。Iron lava, diabase, gabbro diabase, volcanic breccia and volcanic agglomerate together to form subvolcanic rock from Yinmin iron-copper area in Yunnan Province, China. Lithological zoning is obvious. Hydrothermal alteration is closely related to mineralization. Electron microprobe analyses of biotite and chlorite in various lithology of subvolcanic complex rock are conducted. Biotite is considered as the magnesia biotite; most of them are rebalanced biotite, its temperature is 505-590 ℃, lgf（O2）=-12.4-5.25, p=116-226 MPa, h=4.27-8.37 kin, instructed to high temperature and strong oxidizing environment. Chlorite is considered as pycnochlorite, prochlorite, sheridanite, and pelmine, its temperature is 170-235 ℃, lgf（O2）=-12.4-5.25, 1gf（S2）=-13.34-2.50, instructed to mid-low temperature and highly reduced environment. Mineral occurrence, mineral assemblages and geochemical characteristics show that two minerals are characterized by multi-sourced and multi-stage. Biotite alteration represents the main metallogenic period of iron ore; chlorite alteration represents the main metallogenic period of copper ore. Tectono-magmatic thermal events form the later high-ow temperature alkaline and strong reducing fluid, the ore deposit has been clearly superimposed and transformed. These factors suggest that subvolcanic complex rock is feed system for metallogenic element in iron-copper deposit for a long period of time.

关 键 词：矿物化学 黑云母与绿泥石 铁铜矿床 次火山杂岩 云南因民 

分 类 号：P575.1[天文地球—矿物学] P588.12[天文地球—地质学]