关于银山矿床成矿作用的几个问题——兼与《江西银山铜铅锌金银矿床》的作者商榷

ON SEVERAL QUESTIONS OF ORE-FORMING PROCESSES IN THE YINSHAN POLYMETALLIC DEPOSIT,JIANGXI PROVINCE --A DISCUSSION WITH THE AUTHORS OF THE MONOGRAPH "YINSHAN Cu-Pb-Zn-Au-Ag DEPOSIT IN JIANGXI PROVINCE"

银山多金属矿床是一个特大型火山—潜火山热液矿床,具有复杂的多期多阶段的成矿作用和有序的成矿分带。成矿作用主要为火山—潜火山热液作用,但在此之前,还经历了一期由韧脆性剪切带形成而引起的动力变质热液作用。根据矿体与3个旋回潜火山岩体的时空关系,火山—潜火山热液成矿作用又可分为两个成矿期和5个成矿阶段。矿床地质地球化学研究表明成矿作用在空间上具有定向迁移的特点,结合流体动力学计算机数值模拟认为定向迁移的根本原因是构造岩浆脉动和隐伏岩体形态产状。笔者认为,矿区深部可能有隐伏岩体,但对隐伏的斑岩铜矿床不应抱很大希望。

The Yinshan polymetallic deposit, a superlarge, volcanic-subvolcanic hydrothermal deposit in Jiangxi Province, China, is characterized by complex multi-phase, multi-stage ore-forming processes and well-developed ore zoning. The main metallization is volcano-subvolcanic hydrothermal metallization, which was preceded by dynamohydrothermal metamorphism resulting from ductile-brittle shearing. On the basis of the tempo-space relations of the orebodies with sub-volcanic rocks of three cycles, the volcano-subvolcanic hydrothermal metallization may involve two metallization phases and five stages. A geochemical study on the deposit suggests that the metallization be characterized by southward migration in space. Numerical modeling of fluid dynamics suggests that tectono-magmatic pulsation and the occurrence of the concealed igneous body be the cause for the directional migration of metallization. The writer holds that there is a concealed igneous body at depths in the ore district but that the discovery of a concealed porphyry copper deposit is not very promising.