焦家式金矿中铬铝云母化学成分的标型性

Typomorphic Characteristics of Chemical Composition of Chromo-alumino-mica from Gold Deposits of Jiaojia Type

本文系统研究了胶东地区金矿中产出的铬铝云母亚族中３个白云母、１６个绢云母和３２个含Ｃｒ云母种属的化学成分特征。提出了含Ｃｒ云母种属结构层内四面体、八面体及层间离子种类和数量在焦家式金矿成矿过程中的指示作用，阐明了白云母、绢云母及含Ｃｒ云母种属之间的演化特征在与焦家式金矿化有关的成岩成矿作用中的标型意义。

Detailed investigations into typomorphic characteristics of chemical com-position of chrome micas from gold deposits of Jiaojia type in Jiaodong area show that high contents of Cr,Ni,V,Ti,Mg and Fe in octahedral sites and Si in tetrahedral sites and low content of K in interlavers of chrome micas were all in favour of hydrothermal alteration and gave rise to,gold minera-lization.The association of chrome micas formed at the main ore-forming stage with electrum,pyrite,ankerite and quartz in orebodides serves as a good indicator of the precipitation of gold from auriferous hydrothermal fluids.Sericite formed at the early ore-forming stage is widely distributed in altered rocks;muscovite formed at the lato transitional(diagenetic -metallogenetic)stage is obsorved near orebodies.The complete evolution from muse vite thro-ugh sericite to chrome micas existed in the new subgroup of Cr-Al series which had been developed on the basis of the subgroup of Al series known nas muscovite in natural mica.and this also finds expression in the reduction of grain size,decrease of K content and increase of H_2O content in interlayers,and increase of Si in tetrahedral sites and Cr,Ni,V,Ti,Mg and Fe in octahedral sites,indicating strong hydrothermal alteration and intense,gold mineraliza-tion.The uniform,persistent and continued mineralization in the same Jiaojia type gold deposit suggests the continuity and completeness from the rock-forming process to the ore-forming process.