甘肃阳山金矿构造控矿模式

Structural-control model of the Yangshan gold deposit, Gansu

阳山金矿位于扬子板块与秦岭造山带结合带上,矿体赋存于泥盆系三河口群浅变质碎屑岩建造中。矿床受地层、构造以及早侏罗世岩浆活动的共同控制,其中构造控制着岩浆、成矿流体的活动以及矿体的就位,为主要控矿因素。该矿床主要受安昌河—观音坝断裂带控制,带内一系列次级层间剪切带或次级断裂是金矿体的有利赋矿部位。成矿年代学研究及矿区构造应力分析表明,阳山金矿最终形成于第三纪早期,成矿前矿区应力以近SN向挤压为主,成矿期以NE向挤压为主,且应力大小与金矿化成正比。

The Yangshan gold deposit is located in the junction area of Yangzi plate and Qinling orogenic belt. The ore-body occurs in form of epimetamorphic fragment of the Sanhekou Group of Devonian system. The deposit is controlled by strata, structure and the magmatic activity of early Jurassic period. Among them, the structure is the main ore-control factor and dominates the activity of magma and ore fluids, and influences the emplacement of ore body. The deposit is mainly controlled by the Anchanghe-Co-Guanyinba fault, the sub-interlayer shear belts and sub-fault belts of it are the favorable place where gold ore body occurrence. The metallogenic chronology and field tectonic stress analysis show that the Yangshan deposit was finally formed in the early Tertiary period, and the field stress before ore-forming period were mostly the nearly SN strike pressures, and during ore-forming period were mostly the NE strike pressures. The degree of stress has direct ratio with gold mineralization.