陕西宁强巩家河—蒲家沟地区火山岩地质特征及金、银多金属成矿预测

GEOLOGICAL FEATURES OF VOLCANIC ROCKS AND METALLOGENIC PROGNOSIS OF POLYMETALLIC ORE DEPOSITS CONTAINING GOLD AND SILVER IN THE GONGJIAHE-PUJIAGOU AREA, NINGQIANG COUNTY, SHAANXI PROVINCE

宁强巩家河—蒲水沟地区出露的元古界碧口群为浅变质火山—沉积岩系，火山岩为钙碱性系列的细碧—角斑岩建造，产于岛弧构造环境，火山活动以裂隙式喷溢为主，岩浆演化总体反映为一个大的正向旋回。金、银多金属矿化主要产在火山溢出间歇阶段的短暂喷发所形成的火山碎屑岩夹层中或不同岩性的过渡转换部位。矿化受后期改造富集特点明显。

The Proterozoic Bikou Group occurring in the Gongjiahe-Pujiagou area of Ningqiang County is a epimetamorphosed volcanic-sedimentary rock series, which belongs to the spilite-keratophyre sequence formation of calc-alkaline suite. It was formed under the structural environmentof island arc. Volcanic movement was dominant in outpouring from fractures and the magmaticevolution in general reflected a huge positive cycle. The mineralization of gold and silver polymetallic ores is mainly present in the interstratified pyroclastic ropks and the transitional positionswhich were formed in the stages of intermittent outpouring and temporary eruption of volcanoand, the paulopost reformation and enrichment of the gold-silver mineralization are evident.