Economic Potentials of Migmatites Around Nabardo Area, Bauchi Northeastern Nigeria

This study investigates the Nabardo area, northeastern Nigeria for the economical potentials of the migmatites. Field evidence suggests that the study area has undergone an episode of metamorphism and deformations as depicted by the structural features like preferred orientation of the mineralogical and lithologic units. At least two deformational episodes (D1 and D2) which produced S1 and S2 planar fabrics. It was also observed from the field measurements, that the main structural trend within the study area is NNE/SSW. Representative rock samples were divides into several groups. From these groups, selected samples were studied under thin section and analyzed for XRF geochemistry. The petrographic study under thin section reveals the presence of felsic magma with identification of mineral suites of K- feldspar, biotite, quartz and accessory minerals like Zircon and garnet, indicating high grade of metamorphism. Geochemistry data plotted on major tectonic discrimination diagrams gives tholeiite and calc alkaline nature for the protolith of the selected samples. Based on the geochemical plots and REE signatures, fractional crystallization alone cannot account for these migmatites but rather partial melting and metamorphic differentiation are the major source of these migmatites. They are formed by partial melting of mafic rich protolith that were formed during the Pan-African orogeny. Using the first and second order classification of Sawyer, as a guide for morphological classification of the migmatites in the study area, the migmatites are grouped into metatexites, diatexites and nebulites. Results obtained from the geochemistry using concentration map inferred mineralization potential of Nickel (Ni), Chromium (Cr), Zinc (Zn) and industrial minerals.