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冬瓜山铜矿床是铜陵矿集区狮子山矿田中的主要矿床,对于该矿床中斑岩型成矿作用的研究缺乏。本文对冬瓜山矿床深部是否存在斑岩型矿体、斑岩型矿化特征及其与层状矽卡岩型矿化的关系等问题开展研究。冬瓜山矿床深部具有斑岩型矿化的蚀变类型和蚀变分带特征,矿化可分为钾硅酸盐阶段和石英硫化物阶段两个成矿阶段;斑岩型蚀变分带在空间上向外与矽卡岩化带过渡。斑岩型矿化的石英闪长岩形成年龄为140Ma,与上部层状矽卡岩型矿化相关的石英/辉石二长闪长岩应为同期闪长质岩浆形成。深部斑岩型矿化的成矿流体具有由高温向中温演化的特点,与浅部层状矽卡岩型矿化的成矿流体具有相似的演化趋势;二者的成矿流体应该为一个热液系统,深部岩体内部流体演化形成斑岩型矿化,而接触带部位流体演化形成矽卡岩型矿化。
The Dongguashan copper deposit is the main deposit in the Shizishan orefield in Tongling ore district, and there is a lack of research on the porphyry metallogenesis in this deposit. This paper studies the existence of porphyry type ore bodies, porphyry-type mineralization characteristics and their relationship with layered skarn-type mineralization in the deep part of Dongguashan deposit. In the deep part of Dongguashan deposit, there are porphyry-type mineralization alteration types and alteration zoning characteristics. Mineralization can be divided into two mineralization stages, potash-silicate stage and quartz sulfide stage. Porphyry alteration zoning Spatial outward and skarnization transition. The porphyry-type mineralized quartz diorite is formed at a age of 140 Ma. Quartz / pyroxene diorite associated with the upper stratiform skarn-type mineralization should be formed during the same period of dioritic magma formation. Deep porphyry mineralization fluid has the characteristics of evolution from high temperature to medium temperature and similar evolution trend with superficial stratified skarn mineralization fluids. Both ore-forming fluids should be a hot Fluid system, the fluid evolution in the deep rock mass forms porphyry mineralization, and the fluid in the contact zone evolves to form skarn mineralization.