鄂东北地区清水岩金矿地质特征及矿床成因研究

鄂东北地区清水岩金矿主要赋存于桐柏-大别造山带燕山早期清水岩岩体与大别岩群内外外接带所在的北西向断裂破碎蚀变带中,为破碎带蚀变岩与含金石英脉复合型金矿。断裂破碎蚀变带呈平行的舒缓波状或雁行排列,组成岩石为硅化碎裂岩、绢英岩、交代石英岩、碎裂岩、构造角砾岩等,矿体主要呈脉状、透镜状赋存于断裂破碎蚀变带的膨大部位或交叉部位,具尖灭再现,分枝复合及斜列侧伏特征。燕山早期清水岩岩体与金矿成矿的时空关系非常密切,矿床属中低温岩浆热液成因。

甘肃省敦煌市白山金矿地质特征及找矿标志

敦煌市白山金矿位于塔里木板块的东端,北山陆缘活动带古生代柳园-俞井子裂谷带西段,该区主要以钨、金、锑、铁、铜、钒为主的多金属成矿区。区域金矿成矿类型主要为破碎蚀变岩型和含金石英脉型。通过对白山金矿点以往地质勘查工作综合研究和分析,矿区内金矿成矿类型为破碎蚀变岩-含金石英脉型,金矿(化)体主要产于破碎蚀变岩-含金石英脉,金矿(化)体充填于破碎带蚀变岩及围岩节理、裂隙内,矿床为后期岩浆热液多次叠加改造形成,为中低温热液成因。成矿主要受次级断裂构造控制,矿体的规模、形态、产状与断裂构造关系密切,金矿体主要赋存于断裂破碎带中。

狗皮溪-凤坪界金矿矿床地质特征及控矿因素分析

狗皮溪-凤坪界金矿为赋存于赋存于元古界高涧群韧性剪切带蚀变岩中,以充填方式形成,属于受构造韧性剪切带控制的构造蚀变岩型和含金石英脉型矿床,本文主要对狗皮溪-凤坪界金矿矿床的地质特征、控矿因素进行了系统化的分析,并对矿区的找矿前景进行了进一步探讨,为该区域进一步地质找矿提供理论依据及实践经验。

Mineralizing age of the Rushan lode gold deposit in the Jiaodong Peninsula:SHRIMP U-Pb dating on hydrothermal zircon

Zircons from the auriferous quartz vein in the Rushan gold deposit, Jiaodong Peninsula, have high common Pb contents (206Pbc = 2.00%—15.88%) and Th/U ratios (0.31—1.35), and trap primary CO2-H2O fluid inclusion similar to ore-forming fluids, indicating that they grew from high Th/U ratio ore-forming fluids responsible for gold min- eralization. SHRIMP U-Pb analyses of these zircons gave an age of 117±3 Ma comparable with the ages reported by the former researches in the other areas in the Jiaodong Penin- sula, which is interpreted as the age of gold mineralization at Rushan. The age of SHRIMP zircon U-Pb dating with 160±3 Ma from host rock Kunyushan monzogranite is different from that of the gold mineralization, indicating that there is no genetic relationship between gold mineralization and the granitic magmatism. SHRIMP U-Pb dating on hydrothermal zircons from auriferous quartz veins could be used to con- strain the timing of lode gold mineralization and the rela- tionship to relevant hydrothermal event.