论内蒙古额仁陶盖银矿床成岩成矿模式

额仁陶盖银矿床是次火山热液作用产物。燕山晚期本区受太平洋板块边缘的影响,在已存断裂复活条件下,产生壳幔混合作用形成花岗质岩浆,该岩浆在地下浅处发生强烈的结晶分异作用,形成花岗岩和石英斑岩,两者是同一岩浆不同成岩阶段的产物。石英斑岩是成岩阶段的最后产物。分异作用导致银在成岩期及期后成矿热液中富集。矿床地质地球化学证据表明石英斑岩是矿体的直接母岩。地表大气水在成岩成矿中起着重要作用:①有助于发生基底岩石的部分熔融;②有助于岩浆的结晶分异并导致银在石英斑岩( 浆) 中的富集;③有利于形成大量的矿液。

The Diagenic-metallogenic Model of the Erentaolegai Silver Deposit in Inner Mongolia

Through studying the geology and geochemistry of the depostit and the granite, it is clear that the Erentaolegai silver deposit is of subvolcanic hydrothermal genesis. The local area was marginally_subjected to the late Yanshanian orogeny. The fault which had exited revived, forming crust-mantle granite migma. The magma experienced crystallization differentiation,generating granite and quartz porphyry. The quartz porphyry was formed by violent granite magmatic crystallization differentiation, so and hence silver was abundent in late diagenetic stages and post-diagenetic ore solution. Quartz porphyry is the parent rock of the deposit. Meteoric water at the Earth's surface played an important role in the formation of the magma and the deposit: (1)It contributed to the fundamental rock partial melting; (2)It contributed to magmatic crystallization differentiation and the concentration of silver in the quartz porphyry magma; (3)It contributed to the formation of abundant ore solution.