Quartz was studied with respect to its silicon isotopic composition and cathodoluminescence in micro-fine disseminated gold deposits in SW Guizhou and NW Guangxi. The resultsshowed that quartz in wall rocks, ores and ...Quartz was studied with respect to its silicon isotopic composition and cathodoluminescence in micro-fine disseminated gold deposits in SW Guizhou and NW Guangxi. The resultsshowed that quartz in wall rocks, ores and that in association with hydrothermal silicificationare distinctive in silicon isotopes and cathodoluminescence characters. Quartz in association withprimary silicification is non-luminescent while that in wall rocks and associated with secondarysilicification exhibits striking luminescence. Based on the dynamic fractionation of silicon isotopes, it is suggested that the mineralization was accompanied by rapid transport of a primarysiliceous fluid along the major deep fault system into subordinate faults before ore componentsdeposited in favorable strata via penetration and metasomatism. Therefore, a deep origin is implicit for gold deposits of this type.展开更多
天马山硫金矿是铜陵矿集区典型的层控热液叠加改造型矿床,层状矿体中发育大量的矽卡岩矿物。为查明该矿床中矽卡岩矿物的类型及形成环境,探讨矽卡岩与硫、金成矿之间的关系,对主要的矽卡岩矿物开展了矿物学及矿物化学研究,并对矿石进行...天马山硫金矿是铜陵矿集区典型的层控热液叠加改造型矿床,层状矿体中发育大量的矽卡岩矿物。为查明该矿床中矽卡岩矿物的类型及形成环境,探讨矽卡岩与硫、金成矿之间的关系,对主要的矽卡岩矿物开展了矿物学及矿物化学研究,并对矿石进行了硫同位素地球化学研究。研究表明:矿区内的矽卡岩矿物以石榴子石和辉石为主,其中石榴子石以钙铁榴石为主,属于钙铁榴石-钙铝榴石固熔体系列(Gro 0~18.73 And 80.54~99.00 Spe+Pyr+Alm 0.54~1.47);辉石以透辉石为主,其次为钙铁辉石,属于透辉石-钙铁辉石系列(Di 62.35~97.65 Hd 1.89~36.27 Jo 0.31~1.55)。天马山硫金矿的矿物组合(钙铁辉石+透辉石)属于氧化型矽卡岩,表明矽卡岩形成于相对高温和高氧逸度的条件。石榴子石和辉石端元组分特征及辉石Mn/Fe值(0.02~0.07)具有典型的矽卡岩型铜、金矿床特征。矿石硫同位素具有岩浆源的特征,与区内燕山期岩浆-成矿作用形成的矿石一致,而明显区别于喷流-沉积作用形成的矿石,显示成矿作用与燕山期岩浆活动具有密切的成因联系。燕山期中酸性岩浆交代碳酸盐岩围岩形成大量矽卡岩,矽卡岩矿物的形成增加了岩石的孔隙度和渗透率,为晚期硫、金矿床的形成提供了有利条件。展开更多
文摘Quartz was studied with respect to its silicon isotopic composition and cathodoluminescence in micro-fine disseminated gold deposits in SW Guizhou and NW Guangxi. The resultsshowed that quartz in wall rocks, ores and that in association with hydrothermal silicificationare distinctive in silicon isotopes and cathodoluminescence characters. Quartz in association withprimary silicification is non-luminescent while that in wall rocks and associated with secondarysilicification exhibits striking luminescence. Based on the dynamic fractionation of silicon isotopes, it is suggested that the mineralization was accompanied by rapid transport of a primarysiliceous fluid along the major deep fault system into subordinate faults before ore componentsdeposited in favorable strata via penetration and metasomatism. Therefore, a deep origin is implicit for gold deposits of this type.
文摘天马山硫金矿是铜陵矿集区典型的层控热液叠加改造型矿床,层状矿体中发育大量的矽卡岩矿物。为查明该矿床中矽卡岩矿物的类型及形成环境,探讨矽卡岩与硫、金成矿之间的关系,对主要的矽卡岩矿物开展了矿物学及矿物化学研究,并对矿石进行了硫同位素地球化学研究。研究表明:矿区内的矽卡岩矿物以石榴子石和辉石为主,其中石榴子石以钙铁榴石为主,属于钙铁榴石-钙铝榴石固熔体系列(Gro 0~18.73 And 80.54~99.00 Spe+Pyr+Alm 0.54~1.47);辉石以透辉石为主,其次为钙铁辉石,属于透辉石-钙铁辉石系列(Di 62.35~97.65 Hd 1.89~36.27 Jo 0.31~1.55)。天马山硫金矿的矿物组合(钙铁辉石+透辉石)属于氧化型矽卡岩,表明矽卡岩形成于相对高温和高氧逸度的条件。石榴子石和辉石端元组分特征及辉石Mn/Fe值(0.02~0.07)具有典型的矽卡岩型铜、金矿床特征。矿石硫同位素具有岩浆源的特征,与区内燕山期岩浆-成矿作用形成的矿石一致,而明显区别于喷流-沉积作用形成的矿石,显示成矿作用与燕山期岩浆活动具有密切的成因联系。燕山期中酸性岩浆交代碳酸盐岩围岩形成大量矽卡岩,矽卡岩矿物的形成增加了岩石的孔隙度和渗透率,为晚期硫、金矿床的形成提供了有利条件。
