摘要
云英岩主要是由白云母、石英、黄玉、电气石、萤石以及锡石、黑钨矿等矿物组成的浅色蚀变岩石。本文只讨论主要由白云母、石英、黄玉、锂电气石和萤石所组成的云英岩的蚀变类型、蚀变带序、蚀变带和成岩格子。
The alteration zone and its sequence of greisen,composed of muscovite,quartz,topaz,elbaite and fluorite,can be expessed by the(OH,F)-Si-Al com-position-paragenesis diagram.According to the difference of combination of these five paragenetic minerals(paragenetic phases)in greisen,five alteration types can be recognized,which can be differentiated each other by their own characteristic paragenetic mineral assemblage and sequence of alteration zone.The boundaries between the adjacent types are examined by the change of the arrangement of tie lines between coesisting phases(a kind of univari-ant reactions).These five alteration types constitute a petrogenetic grid,characterized by 2,2,1 pencil of rays.Each alteration type corresponds to a diva-riant field.Further more,two evolving series of alteration type can be set up,according to the reduced order of chemical potential of O_(2).
出处
《岩矿测试》
CAS
1985年第2期103-107,I0002,共6页
Rock and Mineral Analysis
