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白银矿田火山碎屑岩及赋矿岩石的深入研究表明，该地区存在一种长英质侵出相火山岩——碎斑熔岩。其主要特征是：①产于矿田酸性火山岩穹的火山活动中心或古火山喷口位置，代表中酸性火山作用晚期岩浆活动的产物，其典型者如折腰山石英角斑质碎斑熔岩体，规模为2×0．5km2，有次火山相石英钠长斑岩和各种火山碎屑岩如晶屑凝灰岩、集块岩及熔岩等分布在其四周；②碎斑熔岩中碎斑为长石和石英，具破而不碎、碎而不离或离而不远的特征，③基质具霏细结构，但多数已发生绢云母化、绿泥石化和黄铁矿化等；④岩石化学上同该地区喷出相石英角斑岩相当，SiO2均大于70ωB％，具有较高的Al2O3含量和Na2O／K2O值，分别为11．16～14．90和1．78～7．43，具I型与S型的混合型特征，⑤稀土元素配分型式具平坦型和富集型两种，分别与白银矿田东西两段酸性火山岩成因类型相对应，微量元素地球化学研究表明碎斑熔岩与区内石英角斑岩属同源岩浆的衍生物．海相火山岩中碎斑熔岩的确立，不仅增加了海相火山作用形式，即便出作用，而且因其占据火山活动中心或岩浆通道位置，在成岩或火山作用期后便成为海底热液对流循环成矿作用中心即热液喷流口．它既标志着黑矿型块状硫化物矿床成矿的相对时期，是在火山作用晚期侵出相碎斑熔
In-depth studies on pyroclastic rocks and ore-hosting rocks in the Baiyin Ore field show that there is a long-quartzitic intrusive volcanic-lithic lava in the area. Its main features are: ¢ 产In the volcanic activity center or ancient volcanic vents of the acidic volcanic dome in the ore field, it represents the product of late-stage magmatic activity of moderate-acid volcanism. The typical is such as the zonal- 2 × 0.5km2, there are sub-volcanic quartz quartz porphyry and a variety of pyroclastic rocks such as crystal tuff, conglomerate and lava and other distribution around it; ② crustal lava in the plaque as feldspar and quartz , Broken without broken, broken away from or not far away from the characteristics of ③ matrix with Fei fine structure, but most have occurred sericitization, chloritization and pyrite mineralization; ④ rock chemistry with the region The eruptions of quartz porphyry corresponded well with SiO2 larger than 70ωB%, higher Al2O3 contents and Na2O / K2O values of 11.16-14.90 and 1.78-7.43, respectively, with I and S Type of mixed features, ⑤ rare earth element type with flat type and enrichment type two, respectively, and the silver deposit east-west two acidic volcanic rocks type of origin, trace element geochemical studies have shown that the crustal lava and the Quartz angle Porphyry is a derivative of the same magmaThe establishment of crustal lavas in marine volcanic rocks not only increases the marine volcanism, but also contributes to the submarine hydrothermal convection recycle after diagenesis or volcanic activity because it occupies the volcanic activity center or magma channel. The center of ore is hydrothermal jets. It not only marks the relative period of mineralization of the black-ore-type massive sulphide deposits, but also invaded the faulting at the late stage of volcanism