Geochemistry, petrogenesis and geological implication of granitic rocks in Igarra area, southwestern Nigeria.

This article focuses on the geochemical and petrogenetic characterization of granitic rocks in the Igarra area of southwestern Nigeria to understand their origin, evolution, and tectonic implications. The study identifies two main granite types—porphyritic and medium- to coarse-grained—both exhibiting metaluminous to weakly peraluminous, high-K calc-alkaline compositions with enrichment in elements such as Rb, Cs, Th, U, and K, and depletion in Nb, P, and Ti. Geochemical evidence suggests these granitoids formed from partial melting of metasedimentary source rocks under low to moderate pressures, with fractional crystallization and limited crustal contamination, within a collisional tectonic setting related to the Pan-African orogeny. The findings contribute to understanding the magmatic processes and tectonic evolution of the Nigerian Basement Complex during late Precambrian continental collision events.