Detailed geological studies and systematic examinations in terms of petrology,petrochemistry, mineralogy and minor clement distribution with respect to a number of typical profiles together with some available experim...Detailed geological studies and systematic examinations in terms of petrology,petrochemistry, mineralogy and minor clement distribution with respect to a number of typical profiles together with some available experimental data, have improved our understanding of the general regularity regarding meso- and epi-hydrothermalal terations of Si^-, Al^-, K^-, Na^- rich wallrocks as is referred to as the “geochemical model of alteration evolution” in this paper. General trend and broad similarities are recognizable in the process of hydrothermal alterations. It is clear that the continued variation in ionic eoncentration of hydrothermal solutions act as the fundamental control determining the development of alteration. As a resuit, differentiation and evolution of the hydrothermal solutions have taken place in response to this variation from the inner parts outwards as well as from the lower parts upwards. Temporally, mineralization is to a first approximation contemporancous with, or somewhat later than, alteration. Spatially, it is reflected by the zonal arrangement of alterations in the following sequence: silicification,petnssie alterations(♀），illitization(or sericitization),montmorilloitization,kaolinization,chloritization-albitization(or propylitization),and etc.Preliminary attempts have been made to apply this“model”to iron and ecpper depositions.展开更多
文摘Detailed geological studies and systematic examinations in terms of petrology,petrochemistry, mineralogy and minor clement distribution with respect to a number of typical profiles together with some available experimental data, have improved our understanding of the general regularity regarding meso- and epi-hydrothermalal terations of Si^-, Al^-, K^-, Na^- rich wallrocks as is referred to as the “geochemical model of alteration evolution” in this paper. General trend and broad similarities are recognizable in the process of hydrothermal alterations. It is clear that the continued variation in ionic eoncentration of hydrothermal solutions act as the fundamental control determining the development of alteration. As a resuit, differentiation and evolution of the hydrothermal solutions have taken place in response to this variation from the inner parts outwards as well as from the lower parts upwards. Temporally, mineralization is to a first approximation contemporancous with, or somewhat later than, alteration. Spatially, it is reflected by the zonal arrangement of alterations in the following sequence: silicification,petnssie alterations(♀），illitization(or sericitization),montmorilloitization,kaolinization,chloritization-albitization(or propylitization),and etc.Preliminary attempts have been made to apply this“model”to iron and ecpper depositions.
