Magmatic Ni-Cu-(PGE)sulfide and Fe-Ti oxide deposits in plume-related large igneous provinces(LIPs)are commonly related to low-Ti and high-Ti series magmas,respectively,but the major factors that con-trol such a relationship of metallogenic types and magma compositions are unclear.Magma fO2 controls sulfur status and relative timing of Fe-Ti oxide saturation in mafic magmas,which may help clarify this issue.Taking the Emeishan LIP as a case,we calculated the magma fO2 of the high-Ti and low-Ti picrites based on the olivine-spinel oxygen barometer,and the partitioning of V in olivine.The obtained fO2 of the high-Ti series magma(FMQ+1.1 to FMQ+2.6)is higher than that of the low-Ti series magma(FMQ-0.5 to FMQ+0.5).The magma fO2 of the high-Ti and low-Ti picrites containing Fo＞90 olivine reveals that the mantle source of the high-Ti series is likely more oxidized than that of the low-Ti series.The results using the'lambda REE'approach show that the high-Ti series may have been derived from relatively oxidized mantle with garnet pyroxenite component.The S contents at sulfide saturation(SCSS)of the two series magmas were calculated based on liquid compositions obtained from the alphaMelts modeling,and the results show that the low-Ti series magma could easily attain the sulfide saturation as it has low fO2 with S being dominantly as S2-.In contrast,the oxidized high-Ti series magma is difficult to attain the sulfide saturation,but could crystallize Fe-Ti oxides at magma MgO content of～7.0 wt.％.Thus,contrasting magma fO2 of low-Ti and high-Ti series in plume-related LIPs may play an important role in producing two different styles of metallogeny.

Yonghua Cao;Christina Yan Wang

Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,Ministry of Education,School of Geosciences and Info-Physics,Central South University,Changsha 410083,China;Key Laboratory of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;CAS Center for Excellence in Deep Earth Science,Guangzhou 510640,China;Guangdong Provincial Key Laboratory of Mineral Physics and Materials,Guangzhou 510640,China

地学前缘（英文版）

[1]Yonghua Cao;Christina Yan Wang-.Contrasting oxidation states of low-Ti and high-Ti magmas control Ni-Cu sulfide and Fe-Ti oxide mineralization in Emeishan Large Igneous Province)[J].地学前缘（英文版）,2022(06):41-58

picrites,FMQ+1,FMQ+2,FMQ+0,SCSS,alphaMelts,metallogeny

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