Chromitites associated with intensely altered dunites and harzburgites from fourteen different localities in the Isla-hiye ophiolites(SE Anatolia)is reported here for the first time.These chromitites were observed as lenticular and banded bodies with disseminated and massive textures and containing magnesiochromite grains with the following composition:Cr2O3=58.91-59.74 wt％,Al2O3=10.85-11.20 wt％,and TiO2=0.09-0.13 wt％.The Mg#[Mg/(Mg+Fe2+)]values of magnesiochromite from the Isla-hiye ophiolite range between 0.52 and 0.60 and their Cr#[Cr/(Cr+Al)]values vary from 0.7802 to 0.7844.These contents vary with a constant pattern,coincident with the estimated parental liquids that have originated from the derivative of a single bulk of boninitic magma together with Al,Ti-poor,and Cr-rich initial contents.The chro-mitites are serpentinised in almost all parts of the study area,and harzburgite and dunite can be observed in dif-ferent locations.Although the overall composition of platinum group elements(PGE)in most examined chro-mitites varies between 97 and 191 ppb,three chromitites from the Islahiye region present enrichments in overall PGE(up to 214 ppb).The mineralogical and geochemical features of chromitites from the Islahiye region exhibit a robust similarity to podiform chromitites in the mantle fragment of supra-subduction zone type ophiolitic bod-ies.The estimated parental magmas of the investigated chromites are consistent with the differentiation of arc-related melts and do not suggest an oceanic spreading centre tectonic environment.The Islahiye chromites are enriched in IPGE(Ir,Os,Ru),with the occasional pres-ence of Ru and Ir and higher Os contents in chromite.Furthermore,we did not find any platinum group miner-als(PGM)associated with the serpentine silicate sample matrix,which would have stated a secondary enrichment in PGEs.All chromitites in the investigated region have high Cr and low Ti values,are defined as magnesiochro-mite and were crystallised from a characteristic boninitic magma.

Nil Yapici;Gael Calo sinda Ngbangandimbo;Nusret Nurlu

Department of Mining Engineering,University of ?ukurova,Adana,Turkey;Department of Geological Engineering,University of ?ukurova,Adana,Turkey;Muhendislik Fakültesi,Jeoloji Mühendisli?i B?lümü,?ukurova üniversitesi,01330 Balcali Adana,Turkey

地球化学学报（英文版）

[1]Nil Yapici;Gael Calo sinda Ngbangandimbo;Nusret Nurlu-.Geodynamic significance and genesis of chromitites from the Islahiye ophiolite(Gaziantep,SE Anatolia)as constrained by platinum group element(PGE)compositions and mineral chemistry characteristics)[J].地球化学学报（英文版）,2022(05):741-752

chromitites,Islahiye,Gaziantep,Chromitites,harzburgites,hiye,magnesiochromite,boninitic,mitites,serpentinised,harzburgite,dunite,podiform,chromites,magnesiochro,crystallised

Geodynamic,significance,genesis,from,SE,Anatolia,constrained,by,platinum,group,compositions,chemistry,characteristics,associated,intensely,altered,dunites,fourteen,localities,ophiolites,reported,here,first,These,were,observed,lenticular,banded,bodies,disseminated,massive,textures,containing,grains,following,Cr2O3,wt,Al2O3,TiO2,Mg#,Mg+Fe2+,values,range,between,their,Cr#,Cr+Al,vary,contents,constant,pattern,coincident,estimated,parental,liquids,that,have,originated,derivative,single,bulk,together,poor,initial,almost,parts,study,area,locations,Although,overall,elements,examined,varies,ppb,three,region,present,enrichments,mineralogical,geochemical,features,exhibit,robust,similarity,mantle,fragment,supra,subduction,zone,type,ophiolitic,magmas,investigated,consistent,differentiation,arc,related,melts,do,not,suggest,oceanic,spreading,centre,tectonic,environment,enriched,IPGE,Ir,Os,Ru,occasional,ence,higher,Furthermore,did,find,any,als,PGM,serpentine,silicate,sample,matrix,which,would,stated,secondary,PGEs,All,defined

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