We present comprehensive petrological and geochemical analyses of chromitites from the 3.3–3.1 Ga Nuggihalli greenstone belt in the western Dharwar craton, India. Our findings provide insights into the primary magma and mantle source compositions associated with these Archean oceanic lithosphere chromitites. Major and trace element data from chromites and clinopyroxenes in the chromitites, combined with thermobarometry and hygrometry calculations and numerical modelling, indicate that the Nuggihalli chromitites are characterized by high-Cr chromites (Cr# = 68.1–78.6) with low TiO2 (0.19–0.29 wt%), Al2O3 (9.10–13.13 wt%) and Ga (4.24–10.37 ppm). These chemical signatures are comparable with those of chromites from high-Cr podiform chromitites and boninites. The clinopyroxenes are mainly augites with high Mg# (93–95). Melts equilibrated with the clinopyroxenes from the Nuggihalli chromitites have high Mg# values (79–86), similar to ancient komatiitic or picritic magmas (Mg# 75–90). Thermobarometry and hygrometry calculations indicate that the clinopyroxenes likely formed at temperatures of 1194–1221°C and pressures of 0.7–5.8 kbar with high water contents (c. 2.4–2.6 wt%), exceeding the water contents of both mid-ocean ridge and ocean island basalts. Numerical modelling of the rare earth elements indicates moderate degrees of partial melting (1 to c. 10%) of a hydrated spinel lherzolite mantle source (water content c. 478–5408 ppm). The parental magmas of the 3.3–3.1 Ga Nuggihalli chromitites are characterized by an enrichment in water (c. 2.4–2.6 wt%) and depletion in the high field strength elements (e.g. Nb and Hf), which are similar to those in boninites and arc magmas. Furthermore, the rock associations in the Nuggihalli greenstone belt, including ultramafic rocks with chromitites, high-Mg basalts and sheets of gabbro–anorthosites, are similar to the rock assemblages of ophiolites and could therefore represent relicts of a Mesoarchean oceanic lithosphere formed in a forearc setting.

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