The Aksug deposit,located in Altay-Sayan region of Russia,is one of the largest porphyry Cu-Mo deposits in SouthernSiberia.The ore-bearing porphyries of the Aksug porphyry Cu-Mo system were formed in post-collisional ...The Aksug deposit,located in Altay-Sayan region of Russia,is one of the largest porphyry Cu-Mo deposits in SouthernSiberia.The ore-bearing porphyries of the Aksug porphyry Cu-Mo system were formed in post-collisional environment.Geochemicallythey belong to calk-alkaline and high K-calk-alkaline series.Rocks are characterized by enrichment of LILE and depletion of HSFE andHREE,showing the importance of subduction-related components in magma generation.Large plutonic intrusions that host porphyrysystems have been formed during collision.The origin of porphyritic rocks is dominantly the mantle with lower crustal contribution.Themainly economically important Cu-Mo mineralization is closely related to a porphyry series in time and space,being emplaced towardsthe end of magmatic activity.Though the emplacement of plutonic and ore-bearing porphyry complexes took place in differentgeodynamic environments,both complexes are characterized by certain similarity in geochemical composition,alkalinity,trace elementcontent,Sr isotopic composition.This fact evidently indicates a common deep-seated magmatic source(at the lower crust-uppermantle level).Low initial ^(87)Sr/^(86)St,sulfur isotopic characteristics and presence of PGE-Co-Ni mineralization in associated pyrite-chalcopyrite ores suggest that mantle source of chalcophile elements was of high importance in porphyry Cu-Mo mineralization of theAksug deposit.展开更多
Precious metal(Pt,Pd and Au)and Re contents in rocks,ores and flotation concentrates of Siberian(Russia)andMongolian porphyry Cu-Mo and Mo-Cu deposits were studied.The following deposits are discussed:Early Devonian p...Precious metal(Pt,Pd and Au)and Re contents in rocks,ores and flotation concentrates of Siberian(Russia)andMongolian porphyry Cu-Mo and Mo-Cu deposits were studied.The following deposits are discussed:Early Devonian porphyry Mo-CuSora deposit(Kuznetsk Alatau Mountains,Russia)and porphyry Cu-Mo Aksug deposit,(northeastern Tuva,Russia);Triassicporphyry Cu-Mo Erdenetiin Ovoo deposit(northern Mongolia).The samples analyzed include unaltered host rocks of plutons,porphyryrocks of ore-bearing series,different types of altered rocks,mineral separate analyses of molybdenite,chalcopyrite and magnetite,aswell as flotation concentrates.Pt,Pd,Au and Re contents were determined using ICP/MS,AAS and inversion voltammetric analysis.PGE abundances in rocks and poorly mineralized samples span a large range from below detection limit to 65 ppb Pt and 74 ppbPd.Re concentrations in whole rock samples range from below detection limit to 89 ppb.Molybdenite has been shown to be the majorhost phase for Re.The results presented show that Aksug deposit reveals elevated PGE and Au contents in ore minerals and flotationconcentrates.High Pd contents in ores of the Aksug deposit are in accordance with the presence of palladium mineralization in the formof palladium telluride merenskyite(Pd,Pt)Te_2.The variety of precious metals and Re contents in the studied deposits could be caused by a complex interplay of several factors,including importance of primary metal concentrations derived from the source,transport of metals to the deposition area,physicochemical properties of the fluid(fo_2,pH,fs,T,P),and depositional conditions.Higher Re contents in molybdenite andchalcopyrite separates are typical for copper-rich Aksug and Erdenetiin Ovoo deposits.Rhenium concentration in sulfides frommolybdenum-rich Sora deposit is significantly lower.Highly oxidized,Cl-rich fluid style at Aksug and Erdenetiin Ovoo was favorable forhigh rhenium solubility and transport to depositional area.The occurrence of significant precious metals contents at Aksug were likelydue to:1)PGE and Au enriched source,2)favorable fluid style(high fo_2,high Cl-activity),promoting high solubility andtransportation of precious metals in ore-forming fluid as chloride complexes;3)moderately reducing depositional conditions from PGE-bearing solutions containing As and Te,facilitating PGM deposition.As for the porphyry systems at the Sora and Erdenetiin Ovoodeposits,they were probably devoid of precursors favorable for the enrichment in PGE and Au or the role of such precursors wasinsignificant.展开更多
The concentrations of platinum-group elements （PGE） have been analyzed in primary magmatic magnetite samples from the Zhireken, Shakhtama and Aksug porphyry Cu-Mo deposits （Siberia, Russia） by laser ablation-induc...The concentrations of platinum-group elements （PGE） have been analyzed in primary magmatic magnetite samples from the Zhireken, Shakhtama and Aksug porphyry Cu-Mo deposits （Siberia, Russia） by laser ablation-inductively coupled plasma mass spectrometry to determine the range of PGE contents in magnetites and to check whether magnetite from two main rock suites （barren plutonic suite and mineralized porphyry suite） has distinct PGE composition. The results presented here indicate that magnetites are enriched in PGE relative to whole-rocks. Comparison of ore-related porphyry and barren plutonic suites shows that magnetite exhibit relatively similar PGE distribution patterns in both suites. Variations in Rh and Ru contents were controlled by the oxygen fugacity during magma crystallization.展开更多
基金Russian Foundation for Basic Research(grant 06-05-64254)China National Science and Technology Supporting Program(2006BAB07B08)
文摘The Aksug deposit,located in Altay-Sayan region of Russia,is one of the largest porphyry Cu-Mo deposits in SouthernSiberia.The ore-bearing porphyries of the Aksug porphyry Cu-Mo system were formed in post-collisional environment.Geochemicallythey belong to calk-alkaline and high K-calk-alkaline series.Rocks are characterized by enrichment of LILE and depletion of HSFE andHREE,showing the importance of subduction-related components in magma generation.Large plutonic intrusions that host porphyrysystems have been formed during collision.The origin of porphyritic rocks is dominantly the mantle with lower crustal contribution.Themainly economically important Cu-Mo mineralization is closely related to a porphyry series in time and space,being emplaced towardsthe end of magmatic activity.Though the emplacement of plutonic and ore-bearing porphyry complexes took place in differentgeodynamic environments,both complexes are characterized by certain similarity in geochemical composition,alkalinity,trace elementcontent,Sr isotopic composition.This fact evidently indicates a common deep-seated magmatic source(at the lower crust-uppermantle level).Low initial ^(87)Sr/^(86)St,sulfur isotopic characteristics and presence of PGE-Co-Ni mineralization in associated pyrite-chalcopyrite ores suggest that mantle source of chalcophile elements was of high importance in porphyry Cu-Mo mineralization of theAksug deposit.
基金This work was supported by grants RFBR(06-05-64254),NSH-4933.2006.5integration project SB RAS IP.6.11.
文摘Precious metal(Pt,Pd and Au)and Re contents in rocks,ores and flotation concentrates of Siberian(Russia)andMongolian porphyry Cu-Mo and Mo-Cu deposits were studied.The following deposits are discussed:Early Devonian porphyry Mo-CuSora deposit(Kuznetsk Alatau Mountains,Russia)and porphyry Cu-Mo Aksug deposit,(northeastern Tuva,Russia);Triassicporphyry Cu-Mo Erdenetiin Ovoo deposit(northern Mongolia).The samples analyzed include unaltered host rocks of plutons,porphyryrocks of ore-bearing series,different types of altered rocks,mineral separate analyses of molybdenite,chalcopyrite and magnetite,aswell as flotation concentrates.Pt,Pd,Au and Re contents were determined using ICP/MS,AAS and inversion voltammetric analysis.PGE abundances in rocks and poorly mineralized samples span a large range from below detection limit to 65 ppb Pt and 74 ppbPd.Re concentrations in whole rock samples range from below detection limit to 89 ppb.Molybdenite has been shown to be the majorhost phase for Re.The results presented show that Aksug deposit reveals elevated PGE and Au contents in ore minerals and flotationconcentrates.High Pd contents in ores of the Aksug deposit are in accordance with the presence of palladium mineralization in the formof palladium telluride merenskyite(Pd,Pt)Te_2.The variety of precious metals and Re contents in the studied deposits could be caused by a complex interplay of several factors,including importance of primary metal concentrations derived from the source,transport of metals to the deposition area,physicochemical properties of the fluid(fo_2,pH,fs,T,P),and depositional conditions.Higher Re contents in molybdenite andchalcopyrite separates are typical for copper-rich Aksug and Erdenetiin Ovoo deposits.Rhenium concentration in sulfides frommolybdenum-rich Sora deposit is significantly lower.Highly oxidized,Cl-rich fluid style at Aksug and Erdenetiin Ovoo was favorable forhigh rhenium solubility and transport to depositional area.The occurrence of significant precious metals contents at Aksug were likelydue to:1)PGE and Au enriched source,2)favorable fluid style(high fo_2,high Cl-activity),promoting high solubility andtransportation of precious metals in ore-forming fluid as chloride complexes;3)moderately reducing depositional conditions from PGE-bearing solutions containing As and Te,facilitating PGM deposition.As for the porphyry systems at the Sora and Erdenetiin Ovoodeposits,they were probably devoid of precursors favorable for the enrichment in PGE and Au or the role of such precursors wasinsignificant.
基金supported by Russian Foundation for Basic Research(Project No:06-05-64254)
文摘The concentrations of platinum-group elements （PGE） have been analyzed in primary magmatic magnetite samples from the Zhireken, Shakhtama and Aksug porphyry Cu-Mo deposits （Siberia, Russia） by laser ablation-inductively coupled plasma mass spectrometry to determine the range of PGE contents in magnetites and to check whether magnetite from two main rock suites （barren plutonic suite and mineralized porphyry suite） has distinct PGE composition. The results presented here indicate that magnetites are enriched in PGE relative to whole-rocks. Comparison of ore-related porphyry and barren plutonic suites shows that magnetite exhibit relatively similar PGE distribution patterns in both suites. Variations in Rh and Ru contents were controlled by the oxygen fugacity during magma crystallization.
