Cr-spinel compositions and the petrogenesis of podiform chromitites in the Kağızman Ophiolite (Ağrı, Eastern Türkiye)

Podiform chromitites are important indicators of mantle processes associated with subduction initiation,yet their formation mechanisms remain debated. This study presents petrographic and mineral-chemical data fromchromitites of the Eastern Ağrı region (Kağızman Ophiolite) in the eastern segment of the İzmir–Ankara–Erzincan SutureZone and evaluates their significance for supra-subduction zone (SSZ) forearc mantle evolution along the northern NeoTethyan margin. The chromitites occur as massive and disseminated bodies hosted by dunite channels within refractoryharzburgite. Sharp spinel grain boundaries and primary silicate inclusions (orthopyroxene ± olivine) preserved withinCr-spinel cores indicate focused melt flow, melt–rock interaction, and chromitite saturation in a forearc mantle setting.Cr-spinels are characterized by high Cr# values (0.57–0.88) and low TiO2 contents (<0.7 wt.%), whereas olivine (Fo90–93)and orthopyroxene (Mg# = 90–94) compositions indicate a strongly depleted mantle source. Field relationships,petrography, and mineral chemistry suggest that chromitite formation occurred during subduction initiation and wasrelated to slab-derived fluid influx and hydrous melting of refractory mantle. The coexistence of different chromititetextures and preserved primary mineral signatures indicates a multi-stage chromitite-forming process linked to evolvingmelt fluxes. Comparison with other Neo-Tethyan and global ophiolitic chromitites supports an SSZ affinity for theKağızman chromitites and highlights the role of integrated petrographic and mineral-chemical approaches in constrainingchromitite genesis and forearc mantle evolution.