The Lake Siah iron±apatite deposit is situated in the Bafq Mining District(BMD),Central Iran.The iron±apatite orebodies are hosted by a succession of rhyolite,rhyolitie tuff,trachyandesite,and andesite of Lo...The Lake Siah iron±apatite deposit is situated in the Bafq Mining District(BMD),Central Iran.The iron±apatite orebodies are hosted by a succession of rhyolite,rhyolitie tuff,trachyandesite,and andesite of Lower Cambrian age.The host rock has undergone wide-spread alteration and mineralization stages including Na(albite-quartz),followed by Na-Ca(albite-calcite--am-phibole-magnetite±quartz±epidote),magnetite-ap-atite,K(biotite±K-feldspar),hydrolytic(sericite-quartz),and argillic(kaolinite--montmorillonite±dickite),respec-tively.Electron microprobe analyses(EPMA)from mag-netite and hematite show significant variations of trace elements.Based on Ni/Cr+Mn and Ca+Al+Mn ver-sus Ti+V diagrams,the majority of magnetite samples belong to Kiruna-type deposits.At least,three generations of fluid inclusions,including solid-bearing(L+V+S)(Type I),liquid-rich(L+V)(Type II-A),vapor-rich(L+V)(Type II-B),and liquid or vapor mono-phase(Type II),are recognized in quartz and apatite.The solid-bearing fluid inclusions in quartz completely homogenized at temperatures of 150 to>530℃with salinities of 30--58 wt%NaCl equiv.Liquid-rich fluid inclusions in apatite homogenized to a liquid phase at 175--210℃,whereas the vapor-rich fuid inclusions homogenized to a vapor at 335-350°C.Oxygen isotope analysis was carried out on quartz and magnetite.The hydrogen and oxygen isotopic compositions of quartz(8"Onuid values of 7.57-11.04%)show that with progress in time the ore-forming solutions gradually evolved from a magmatic to meteoric-dominated source.展开更多
文摘The Lake Siah iron±apatite deposit is situated in the Bafq Mining District(BMD),Central Iran.The iron±apatite orebodies are hosted by a succession of rhyolite,rhyolitie tuff,trachyandesite,and andesite of Lower Cambrian age.The host rock has undergone wide-spread alteration and mineralization stages including Na(albite-quartz),followed by Na-Ca(albite-calcite--am-phibole-magnetite±quartz±epidote),magnetite-ap-atite,K(biotite±K-feldspar),hydrolytic(sericite-quartz),and argillic(kaolinite--montmorillonite±dickite),respec-tively.Electron microprobe analyses(EPMA)from mag-netite and hematite show significant variations of trace elements.Based on Ni/Cr+Mn and Ca+Al+Mn ver-sus Ti+V diagrams,the majority of magnetite samples belong to Kiruna-type deposits.At least,three generations of fluid inclusions,including solid-bearing(L+V+S)(Type I),liquid-rich(L+V)(Type II-A),vapor-rich(L+V)(Type II-B),and liquid or vapor mono-phase(Type II),are recognized in quartz and apatite.The solid-bearing fluid inclusions in quartz completely homogenized at temperatures of 150 to>530℃with salinities of 30--58 wt%NaCl equiv.Liquid-rich fluid inclusions in apatite homogenized to a liquid phase at 175--210℃,whereas the vapor-rich fuid inclusions homogenized to a vapor at 335-350°C.Oxygen isotope analysis was carried out on quartz and magnetite.The hydrogen and oxygen isotopic compositions of quartz(8"Onuid values of 7.57-11.04%)show that with progress in time the ore-forming solutions gradually evolved from a magmatic to meteoric-dominated source.
