Conclusion
The rocks of the study area belong to the south western basement complex terrain of Nigeria. It is underlain by migmatite gneiss (porphyroblastic gneiss, banded gneiss and granite gneiss), granites (quartz-rich granitoid and granodiorite) and pegmatite. The dominant mineral assemblages from petrographic studies include quartz, muscovite, hornblende, biotite and other accessory minerals which exhibit different optical properties. The biotite-hornblende mineral possesses dominant planar grain contact oriented at different angles and the undulating contact at irregular intervals in thin section. The hornblende-muscovite contact has equal proportion of planar and undulating contact.
Major oxides analyzed for include CaO, SiO2, Al2O3, Fe2O3, MgO, Na2O, and K2O. The compositional study revealed that the rocks have high alumina content. There is strong to moderate correlation between the percentages of SiO2 and other oxides. Indices of alteration suggest intense weathering and other magmatic alteration processes which may include partial melting and recrystallization during metamorphism. The gneisses have high liquidus temperature common to metamorphic rocks.
The granitic rocks are characteristic Pan African rocks suggesting they were emplaced into the migmatized host rock (Precambrian) approximately +550 Ma years. Emplacement of newer magmatic bodies into the host rocks suggest different phases of deformation and alteration of the magmatic content. Until now, erosion has altered the rocks of the area into its present state.