Geological Field Mapping of the Crystalline Basement Rocks in Kaduna State

Kaduna State in North West Nigeria is underlain by a diverse assemblage of Precambrian basement complex rocks including migmatites, gneisses, schists, granitoids, and younger granites, whose spatial distribution and petrological relationships require updated systematic documentation. This study presents a geological field mapping exercise conducted over a fifty-square-kilometre area in southern Kaduna State, with the objective of producing a revised geological map and characterising the petrological and structural relationships of exposed basement units. Field mapping was undertaken at a scale of 1:25,000 using topographic base maps and handheld GPS devices, with lithological contacts, foliations, lineations, and structural measurements recorded systematically. Representative rock samples were collected for petrographic thin section preparation and geochemical analysis by X-ray fluorescence spectrometry. Major element oxide data were plotted on standard discrimination diagrams to classify granitoid compositions and infer tectonic setting. Structural data were processed using stereographic projections to identify dominant deformation fabrics and folding episodes. The study integrates findings with the published Geological Survey of Nigeria 1:250,000 map sheets to produce a higher-resolution geological map of the study area. This field mapping exercise equips undergraduate students with fundamental geological observation and data compilation skills transferable to professional geological survey, mining, and oil and gas careers. Keywords: geological mapping, basement complex, Kaduna State, granitoids, petrography.