It is widely accepted that moderately to highly oxidized magmas are needed to form porphyry copper deposits(PCDs).However,only a few studies have attempted to investigate the effects of variable magmatic fO2 values on...
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It is widely accepted that moderately to highly oxidized magmas are needed to form porphyry copper deposits(PCDs).However,only a few studies have attempted to investigate the effects of variable magmatic fO2 values on the formation of *** on previously published studies,the magma oxygen fugacity of giant PCDs is mainly concentrated betweenΔFMQ−0.5 andΔFMQ+2.5,with the first quartile,median,and third quartile being+0.8,+1.3,and+1.7,*** this work,we have carried out numerical modeling,which shows that the S^(2−)used to precipitate Cu accounts for approximately 90%of total sulfur atΔFMQ+1 but drops to 33%–38%and 15%–25%atΔFMQ+2 andΔFMQ+3,*** leads to a decrease of 88%–96%in Cu precipitation efficiencies fromΔFMQ+1 toΔFMQ+*** petrological model further shows that the maximum Cu precipitation efficiency(and,therefore,Cu endowments)occurs at aroundΔFMQ+***,therefore,highlight that moderately oxidized magma(ΔFMQ=∼1)rather than highly oxidized ones(ΔFMQ>∼2)is optimal for the generation of giant PCDs.
It is widely accepted that moderately to highly oxidized magmas are needed to form porphyry copper deposits （PCDs）.However,only a few studies have attempted to investigate the effects of variable magmatic fO2values ...
It is widely accepted that moderately to highly oxidized magmas are needed to form porphyry copper deposits （PCDs）.However,only a few studies have attempted to investigate the effects of variable magmatic fO2values on the formation of *** on previously published studies,the magma oxygen fugacity of giant PCDs is mainly concentrated betweenΔFMQ-0.5 and ΔFMQ+2.5,with the first quartile,median,and third quartile being +0.8,+1.3,and+1.7,*** this work,we have carried out numerical modeling,which shows that the S2-used to precipitate Cu accounts for approximately 90% of total sulfur atΔFMQ+1 but drops to 33%–38% and 15%–25% at ΔFMQ+2 andΔFMQ+3,*** leads to a decrease of 88%–96%in Cu precipitation efficiencies from ΔFMQ+1 to ΔFMQ+*** petrological model further shows that the maximum Cu precipitation efficiency （and,therefore,Cu endowments） occurs at aroundΔFMQ+***,therefore,highlight that moderately oxidized magma（ΔFMQ=～1） rather than highly oxidized ones （ΔFMQ>～2） is optimal for the generation of giant PCDs.
<正>云南哀牢山-金沙江富碱侵入岩带内发育许多与铜、金、钼矿化有关的富碱斑岩体,如玉龙二长花岗斑岩、马厂箐花岗斑岩、长安冲石英正长斑岩、北衙石英正长斑岩、姚安正长斑岩,也有一些不成矿的岩体,如剑川粗面斑岩、六合正长斑岩。众多学者做过年代学和地球化学研究显示它们的年龄在30~40 Ma之间,是大陆内部的大型走滑-伸展作用的产物(Hou et al.,2003;毕献武等,2005;徐兴旺等,2006)。
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