火山作用与银矿化

我国与火山作用有关的银矿床占大、中型银矿床总数的33.5 %。燕山旋回是我国与火山岩和潜火山岩有关的银矿最重要的成矿期。这类银矿几乎都产于深大断裂边缘或次级构造交汇部位、 地槽区海相火山活动地带及地台活化区陆相火山活动地带。硅化和钠化与银矿化最为密切。矿液中的Au、Pb、Sc、Mn、Cd对银的成矿作用有积极影响。银在矿石中的分布特点显示，矿石中95%以上的银呈独立银矿物存在，方铅矿、闪锌矿和黄铜矿是银的最重要载体矿物，这为银的充分回收利用提供了地质依据。

Volcanism and Silver Ore

In China, silver deposits related to volcanism take up 33.5% of all large and mi ddle silver deposits. Yanshan cycle is the most important metallogenic time for the silver deposits related to volcanic and subvolcanic rocks. These kind of dep osits mainly locate on the margin of deep fractures, the cross of deep fractur es and their low class fracture, marine volcanic belt and continental volcanic belt in reactive platform. The silver mineralization related most close to sili fication and sodification. Au, Pb, Sc, Mn and Cd in ore forming fluid have posi tive effections on silver mineralization. More than 95% Ag in the ores are indep endent silver minerals. The most important silver bearing minerals are galena, sphalerite and pyrite.