Petrography of Rocks Around Rudibida Ganjuwa, Bauchi State, Part of Sheet 128 Se

This research investigates the geology and petrography of the basement rocks around Rudibida in Ganjuwa LGA, Bauchi State, Nigeria, within coordinates N10° 30' 56"–N10° 32' 56" and E9° 56' 42"–E10° 0' 00". Field mapping identified a migmatite-gneiss complex displaying classic anatectic structures - stromatic banding, pinch-and-swell boudinage, ptygmatic folding and penetrative gneissic foliation - intruded by concordant, syn-tectonic pegmatite sills/dykes and later, discordant, post-tectonic east-west trending basaltic dykes. Petrographic study of seven representative thin sections (BL1, BL2A, BL3, BL6, BL16, BL20 and BL22) confirmed a dominantly granitoid (hornblende/biotite granite and granodiorite) mineralogy, with one sample (BL2A) recording a sillimanite-muscovite metasedimentary signature, one (BL22) recording an orthopyroxene-cordierite granulite-facies assemblage, and one (BL3) confirmed as an olivine basalt. The area is hence part of the pan African Migmatite terrain of the basement complex of Nigeria.