Rare metals-bearing potential of pegmatites in Itasa area, Southwestern Nigeria

Abstract

Pegmatites serve as crucial hosts for both gemstones and rare metals, playing an essential role in global technological industries. Despite extensive research on rare metal deposits in Nigeria, the Itasa area remains underexplored regarding rare metal and rare earth element mineralisation. This study assesses the rare metal-bearing potential of pegmatites in southwest Nigeria’s Itasa area. Detailed geological mapping clearly identified diverse rock types, including granite-gneiss, chlorite-schist, hornblende-gneiss, and biotite-granite gneiss. A total of nine whole-rock pegmatites and four muscovite extracts samples were collected for geochemical analyses and petrographic examination. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine the elemental compositions, revealing that rare metals such as Li, Ta, Nb, Rb, Cs, and Sn are relatively depleted. Elemental ratios, including K/Rb and Ba/Rb, indicate low fractionation and poor mineralisation. Consequently, the overall enrichment levels fall well below those of economically viable pegmatites, strongly suggesting that the Itasa pegmatites are unlikely to be economically exploitable.