Emeishan large igneous province (ELIP), one of the largest continental volcanic provinc-es worldwide (e. g., Karoo), is extensively distributed along the western margin of the Yangtze Block. Even though the consensus that the ELIP is of a plume-related origin has been reached for decades, the role of crustal contamination in the petrogenesis of these basalts is still debatable so far. This paper firstly reports the Ba isotopic compositions of the continental flood basalts from the Lijiang, Miyi and Emeishan regions to discuss the genesis of basalts from the ELIP. According to their TiO2 contents and Ti/Y ratios, these basalts are divided into two groups, the low-Ti basalts from Lijiang and the high-Ti basalts from Miyi and Emeishan. The Ba isotopic compositions show that the low-Ti basalts have the δ138/134Ba values from -0.33‰ to +0.23‰ with an average of -0.02‰ ± 0.40‰, and the high-Ti basalts from-0.38‰to+0.38‰with an average of 0.038‰± 0.36‰, all of which show a wider range of Ba iso-topes relative to that of the primitive mantle (PM). This is unlikely to be explained by partial melting, fractional crystallization or even chemical weathering owing to little Ba isotopic fractionation during these processes. In contrast, variable extents of crustal contamination into the basaltic magmas more likely resulted in such isotopic diversity. The ratios of incompatible elements (e. g., Nb/U, La/Nb, and Nb/Y) further suggest that the low-Ti basalts experienced higher degrees of crustal contaminations than those high-Ti basalts, which is well consistent with their spatial distributions. In general, the basal-tic magmas in the ELIP were probably contaminated by different degrees of crustal materials during their upwelling to the surface.

Dong Yi;Jing Zhao;Chunhui Li;Xiuhong Peng

Department of Geochemistry,College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China

地球科学学刊（英文版）

[1]Dong Yi;Jing Zhao;Chunhui Li;Xiuhong Peng-.Crustal Contaminations Responsible for the Petrogenesis of Basalts from the Emeishan Large Igneous Province, NW China:New Evidence from Ba Isotopes)[J].地球科学学刊（英文版）,2022(01):109-120

Contaminations,provinc,Karoo,Miyi,topes

Crustal,Responsible,Petrogenesis,Basalts,from,Emeishan,Large,Igneous,Province,NW,China,New,Evidence,Isotopes,igneous,province,ELIP,one,largest,continental,volcanic,worldwide,extensively,distributed,along,western,margin,Yangtze,Block,Even,though,consensus,that,plume,related,origin,has,been,reached,decades,role,crustal,petrogenesis,these,basalts,still,debatable,far,This,paper,firstly,reports,isotopic,compositions,flood,Lijiang,regions,discuss,According,their,TiO2,contents,ratios,are,divided,into,two,groups,low,show,have,134Ba,values,average,to+0,which,wider,range,relative,primitive,mantle,PM,unlikely,explained,by,partial,melting,fractional,crystallization,even,chemical,weathering,owing,little,fractionation,during,processes,In,contrast,variable,extents,basaltic,magmas,more,resulted,such,diversity,incompatible,elements,Nb,further,suggest,experienced,higher,degrees,contaminations,than,those,consistent,spatial,distributions,general,were,probably,contaminated,different,materials,upwelling,surface

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