Mineralogical and Genetical Aspects of the Doyashiki Kuroko Deposits, Hokuroku Basin, Japan

Abstract. A detail investigation of ore and gangue minerals was performed on the Doyashiki Kuroko deposits, Hokuroku basin, Japan for the first time. Main ore minerals are sphalerite, galena, pyrite, chalcopyrite, tetrahedrite-tennantite and digen-ite. Small amounts of enargite, wittichenite, electrum, covellite, bornite, marcasite and hematite are also observed. Quartz, barite and gypsum are common gangue minerals. Homogenization temperatures and salinities of fluid inclusions in quartz, sphalerite and barite range from 190 to 240C and 3.0 to 5.5 wt% NaCl equivalent, respectively. The FeS contents of sphalerite and Ag contents of electrum were 0.12 to 0.18 mol %, 39.0 to 39.6 atom %, respectively. The chemical composition of digenite as a primary mineral shows high sulfur contents.
These data indicate that ore fluid responsible for digenite and associated ore minerals was characterized by a range of high sulfur fugacity with a moderate formation temperature. This is concordant with the mineral assemblage of bornite-pyrite and chalcopyrite, which shows high sulfur fugacity conditions. It seems that the mineralization closely associated with acidic volcanism has occurred around 13 Ma of Middle Miocene on the seafloor at the depth of about 1500 m.     

浅谈紫金山铜矿区蓝辉铜矿及其他铜硫化物特征

紫金山铜矿区的蓝辉铜矿成因一直存有争论,其关键点在于对次生成因或原生成因的认识。文章对铜矿石光片进行反光显微镜观察,总结了铜矿物的生成顺序及分布特点,并讨论前人对蓝辉铜矿成因研究的不同成果,提出自己的一点研究看法。     

江西东乡铜矿中含铜硫化物的几种 微结构及其地质意义

根据对江西东乡铜矿矿石矿物的光学显微镜以及电子探针的研究,发现了该矿石中久辉铜矿与蓝辉铜矿呈页片状或互界状的交生构造,同时还存在着斑铜矿-蓝 辉铜矿的环带状构造。这两种构造中的蓝辉铜矿在成分上有明显差异,前一种构造中的蓝辉 铜矿不含Fe,而环带构造中的蓝辉铜矿含一定量的Fe。讨论了两种蓝辉铜矿各自的形成机制及其地 质意义。     

紫金山金铜矿床深部成矿作用研究和找矿前景评价的关键

紫金山铜金矿床是典型的高硫化浅成低温热液矿床, 发育巨厚的热液蚀变帽, 多孔状石英和高级泥化蚀变带等标志性特征; 特别是在金矿体之下出现垂直厚度超过1000米的巨大铜矿体, 属于蓝辉铜矿－铜蓝－硫砷铜矿－明矾石矿物组合的高硫化型浅成低温热液铜矿床类型, 铜硫化物的矿物学研究预示着深部可能变为斑岩型铜矿床。     

辉铜矿和蓝辉铜矿木质细胞结构的EPMA研究

运用EPMA和SEM分析技术对辉铜矿和蓝辉铜矿木质细胞体的细胞核、细胞壁和细胞之间的成分变化、多种环境下的木质细胞形状进行了研究,对形成机理作了探讨。