湖南麻阳铜矿自然铜形态特征及其成因意义  

NATIVE COPPER ORE-TEXTURAL CHARACTERISTICS OF THE MAYANG DEPOSIT AND THEIR CONSTRAINTS ON GENESIS

作　　者：王大鹏[1] 张乾[1] 祝朝辉[1] 蒋寿平[2] 陈龙兵[2] 

机构地区：[1]中国科学院地球化学研究所矿床地球化学国家重点实验室 [2]麻阳铜矿,湖南麻阳419413

出　　处：《矿物学报》2007年第3期384-387,共4页Acta Mineralogica Sinica

基　　金：东华理工学院核资源与环境教育部重点实验室开放科研基金项目(批准号:060604);中国科学院重要方向项目(批准号:KZCX3-SW-125)

摘　　要：麻阳铜矿是白垩纪砂岩容矿的自然铜矿床,研究了自然铜的产出状态和矿石结构特点过程中,确定了该矿床自然铜的三种存在形式:①岩屑型原生自然铜,是剥蚀源区已有的自然铜矿石经河流搬运而来,这种自然铜可作为寻找剥蚀源区自然铜矿化的标志;②后期热液充填型自然铜,自然铜粒度粗大,形状多变,大多产于碎屑之间的胶结物中,常见交代溶蚀碎屑;③裂隙中次生自然铜,多呈大片的树枝状等不规则状。认为含自然铜岩屑来自剥蚀源区原生自然铜矿化,碎屑粒间充填的自然铜是成岩期或更晚期热液作用的产物,沿断裂或裂隙形成的树枝状-不规则状自然铜是成岩期后构造活动的产物。Tne Mayang copper deposit is a native copper deposit, hosted by Mesozoic sandstones and conglomeratic sandstones in the Yuamna Basin. By studying native copper ore-textural characteristics by transmitted and reflected light microscopy, three forms of native copper were distinguished： ①native copper mineralization occurs in detrital siliceous rocks, which were formed in the provenance district （Xuefeng Mountain region） , and this type of copper is the possible genetic marker of the Mayang copper mine; ②the disseminated native copper mineralization, occurring as a kind of cements, always replaces detrital minerals, and are associated with calcite cements or sericitized matrix. The above characteristics of disseminated native copper are similar to those of hydrothermal replacement deposits, and the native copper was formed during the post-depositional stage or even post-diagenetic stage; and ③the secondary native copper occurs in fault surface with gypsum, this type of mineralization is controlled by fault which cuts through the disseminated orebedies. As above described, the types of native copper mineralization show a multiple evolution for the Mayang native copper mine.

关 键 词：自然铜 矿石结构 矿化 湖南麻阳 

分 类 号：P571[天文地球—矿物学] P578.1[天文地球—地质学]