影壁山火山角砾岩型金矿地质特征与成矿机制

影壁山金矿是一个产于火山角砾岩筒内的火山热液型金矿床，而角砾岩筒又受区内近东西向的断裂F1的控制。矿体产出的位置严格限定在角砾岩筒内多组不同方向的断裂破碎带内。金矿化主要与强硅化、细粒-微细粒黄铁矿蚀变有关，矿化极不均匀，从岩筒中部向岩筒边部品位有降低的趋势。在成矿机制上侏罗纪火山岩(K1y)沿早期断裂F1(导矿构造)上盘上侵形成角砾岩筒，而后期含金火山成矿热液又沿角砾岩筒内部张性断裂(容矿构造)充填而形成金矿床。

The Characters and Mechanism of Yingbishan Gold Ore Deposit in the Volcanic Breccia Chimney

Yingbishan gold ore deposit is a volcanic hydrothermal deposit hosted in the volcanic breccias chimney whose occurrence is controlled by the nearly-transmeridional fracture F_1 in the ore field.The ore bodies are strictly confined within the fractured zones with different orientations in the pipe, and the nonhomogeneous gold mineralization mainly displayed the relationship between the mineralization and the intense silicatization as well as the fine-micro grained pyritization . From the middle of the pipe towards the marginal rim the ore-tenor exhibits the decreasing tendency implying that the mineralizing material sources have originated from the central parts of the pipe.In the term of the ore-forming process mechanism, the Jurassic period volcanic rocks (K1y)invaded along the hanging wall of the incipient fracture F1(conducting structures) and formed the breccias chimney, and the later stage auric volcanic hydrothermal fluids filled the tensional fractures (host structures)in the pipe finally yielded this volcanic hydrothermal gold ore deposit.