The 2.7Ga Ramagiri-Hungund composite greenstone belt, or tectonostratigraphic superterrane (RHST), is one of a series of volcanic dominated supracrustal belts in the eastern Dharwar craton. Extensive outcrops of well preserved pillow basalt occur in the Penakacherla Terrane (PT); these are amphibolite facies, and relatively undeformed. Basalts are tholeiitic, and compositionally uniform, where Mg# spans 64 to 60. REE patterns are coherent, with no Eu anomalies, near flat HREE and systematically depleted LREE (La/Sm c n = 0.68-1.08; Gd/Yb c n = 0.91-1.08). Chromium (284-671ppm), Co, and Ni contents are high relative to Phanerozoic arc tholeiites. Dominantly negative Nb and Ti anomalies relative to REE, and Zr/Nb = 15-25 compared to 32 in average N-MORB, signify a convergent margin setting with a depleted mantle wedge; they plot with the low Ce-Yb trend of intraoceanic arcs. High Mg#, and Cr, Co, Ni contents may be indicative of a plume-influenced mantle wedge. The basalts are distinct from most Phanerozoic arc basalts in having a spectrum of negative to positive Nb and Zr-Hf anomalies, where the most positive anomalies are in conjunction with lowest La/Sm c n . The former can be accounted for by addition of LREE from the slab to subarc mantle wedge in fluids, with conservative behaviour of Nb and Zr-Hf. The latter reflect a two stage melting history; first stage depletion of incompatible elements in the wedge, leaving positive anomalies of Nb and Zr-Hf, that are inherited by second stage melts. Cesium, Ba, and Rb show coherent enrichments relative to Th, Nb, and LREE, consistent with a frontal versus rear arc setting based on modern arcs.