中文摘要：

目前已经广泛认同斑岩型Cu-Au（-Mo）矿床是在相对较高的氧化性含矿流体作用下形成的。但是随着研究的深入,逐渐发现了一系列具备还原性特征的斑岩型矿床,这些矿床往往不发育表征高氧逸度的原生磁铁矿和硫酸盐矿物。文中对几种与斑岩型矿化相关的花岗岩分类进行了分析讨论,并采用氧化型和还原型花岗岩分类方案,将对应的斑岩型矿床划分为氧化性斑岩型矿床（OPD）和还原性斑岩型矿床（RPD）。结合相关资料,认为还原性流体中所含有的CH4可能来自邻近的S型花岗岩的混染作用,但是不排除是经地球排气作用从地幔进入到地壳的可能性。结合实际还原性斑岩型矿床研究,文中给出了一个化学模型,认为CH4和SO2属于岩浆系统自生成分,在特定物理化学阶段发生反应,形成H2S和CO2,从而抑制了硫酸盐矿物的形成。这两类矿化系统的成矿流体来源、金属溶解-运移-沉淀以及成矿物质富集-分散-贫化等特征存在较为明显的差别。由于低氧逸度条件不利于成矿金属物质（Cu、Mo等）的迁移和富集,所以RPD矿化系统成矿潜力往往低于OPD矿化系统,但是可以发育次级斑岩型Au矿。结合实验分析结果,文中给出了OPD和RPD矿化系统流体成矿对比模式,认为如果原始岩浆中存在大量的成矿物质,RPD矿化系统可以形成＂两端员矿化＂,即底部形成硫化物矿床,顶部形成次级斑岩型金矿床。

英文摘要：

It is widely accepted that porphyry type deposits were formed from some oxidized ore fluids.But recently,some typical ilmenite-bearing,reduced Type-I granite related porphyry Cu-Mo-Au deposits with relatively reduced ore-forming fluids were found,in which primary hematite,magnetite and sulfate minerals are absent.Some classification schemes of porphyry-related granitoids are discussed in this paper,and the porphyry related deposits are subdivided into the oxidized（OPD） and reduced（RPD） types accordingly.According to related research results,the CH4 contained in RPD fluid system is proposed to be derived from the contamination of Type-I granite with S-type granite,but it is also possible that CH4 comes from the degassing process of the Earth interior.A chemical model is set in order to interpret the role of reduced fluids in porphyry metallogenesis.According to the model,H2S and CO2 are derived from the reaction between CH4 and SO2,both of which come from the same evolved igneous system,which inhabits the formation of sulfate.The characteristics of ore-forming fluid sources,metal-solubility,transportation,precipitation,enrichment and depletion are obviously different in OPD and RPD systems.The low oxygen fugacity is not propitious for transportation and enrichment of Cu and Mo,which causes the poor prospective of RPD system,whereas the Au will be transported under reducing conditions and deposit in some sites far away from the granite system,forming a cogenetic subclass porphyry Au deposits.An ＂end member metallogenic model＂,with sulfide ores in the bottom and porphyry Au ores on the top,is speculated if the contents of metals and reduced S in primary magma are appreciably enriched.