GEOLOGY AND PETROGRAPHY OF ROCKS AROUND BUTAWA, KAFIN MAGAJI AND ENVIRONS, PART OF SHEET 79NE NORTHWESTERN NIGERIA

Abstract

The geology and petrography of rocks of the Nigerian Basement Complex around Butawa–Kafin Magaji, Northwestern Nigeria, were investigated using geological mapping at a scale of 1:25,000, GIS-based digitization, and petrographic analysis, to map the lithological units and their structures and study their mineralogical compositions. The  geologic mapping of the study area identified two rock units; granite gneiss covering about (≈70%) and coarse-grained granite occupied about (≈25%), with minor pegmatites and quartz veins occupied about (≈5%). Petrographic study revealed that, the granite gneiss exhibits a well-defined foliated texture and is composed of quartz (≈30%), plagioclase (≈35%), microcline (≈7%), and biotite (≈10%), reflecting medium grade metamorphism associated with the Pan-African orogeny. The coarse-grained granite contains orthoclase (≈15%), quartz (≈25%), plagioclase (≈35%), biotite (≈7%), microcline (≈5%), and fluorite (≈6%), consistent with a felsic plutonic origin and late-stage magmatic evolution. Structural mapping documents NNE–SSW trending joints, quartz veins, and minor faults that align with regional Pan-African stress fields. The occurrence of xenoliths within the coarse-grained granite suggests partial assimilation of country rock during emplacement, while pegmatite and quartz veins represent later-magmatic and hydrothermal activity. The integrated lithological, petrographic, and structural data indicate that the area records multiple episodes of deformation, metamorphism, and granitoid magmatism typical of the Pan-African tectonic cycle. These findings improve understanding of Basement Complex evolution in northwestern Nigeria and highlight the area’s potential for industrial mineral and construction materials and the structures that hold potential for mineralization.