Preliminary Studies of Pegmatites of Ogodo-Odobola Area of Idah Sheet 267NW, North-Central Nigeria

Abstract

Pegmatites in the world over have been acknowledged to serve as host to lots of minerals (industrial, ore and gemstones). Recently, there is an upsurge in the interest for pegmatite deposits due to the newly discovered important uses of lithium ores among others. The granitic pegmatite of Ogodo-Odobola in Ajaokuta, Central Nigeria belongs to the pegmatite belt of North-Central Nigeria that has received very little attention and consequently, yet to be well studied. Therefore, detailed geological field mapping of the pegmatites and host rocks aimed at understanding their mode of occurrence and field relationship and to assess their mineralization potentials was conducted. The methods employed for this study include both geological fieldwork and laboratory analysis. Twelve (12) representative samples were selected for petrographic analysis. Geological fieldwork shows the study area is underlain by migmatite gneiss, schist, with intrusions of granite and pegmatite. The pegmatites occur in tabular form with varying widths and lengths. Principal joint directions show NNE-SSW direction which is believed to have influenced the pegmatite emplacement. Petrography of the representative rock samples reveal an average mineralogical composition of hornblende, biotite, quartz, plagioclase, microcline, muscovite, myrmekite and opaque minerals for the host rocks. While microcline, plagioclase, muscovite, biotite, and accessory and opaque mineral for the pegmatites. The pegmatite of the study area is worth probing as the results have shown prospect for possible economic minerals.