ECONOMIC POTENTIALS OF THE PEGMATITES OF ERUKU AREA, SOUTHWESTERN NIGERIA

The close proximity of the pegmatites of Eruku area to the strongly mineralized pegmatites of Egbe area and lack of published work on those from the former formed the basis of this research. Sub-parallel, steeply-dipping, lenticular/podlike pegmatite bodies occur in the Eruku area, southwestern Nigeria. They are emplaced within the late Proterozoic to early Paleozoic crystalline basement complex rocks. Some of these pegmatites are mineralized while others are barren. The barren pegmatites are sources of industrial minerals like feldspar and quartz. The mineralized pegmatites are also sources of feldspar and quartz and, in addition, columbite – tantalite, cassiterite, garnet and coloured varieties of tourmaline. Structural features present in the pegmatites include their linear disposition, crude zoning within the rocks and occurrence of some minerals across the contact zone. Available geochemical data indicate that the mineralized pegmatites classify as Li-Be+Ta pegmatites. They are genetically related to differentiation and progressive crystallization of a fertile granitic magma under non-equilibrium conditions during the cooling period, while the barren ones may be products of metamorphism in a high grade metamorphic terrain