In recent decades, the use of new field technologies used in the mining world and very little used in academia has become very important in several research disciplines. The recent development of portable field measuring instruments makes it possible to acquire a large amount of data without the need for costly sampling and analysis campaigns. As part of the «Geochemistry Geophysics Technology in Mining Exploration (T2GEM)» project, the acquisition of a portable X-ray fluorescence at the Petrology-Metallogeny laboratory at the STRM UFR of the Félix Houphouët-Boigny University (Côte d’Ivoire) has made it possible to promote the use of these new technologies as part of a scientific project whose research focus is the distribution of rare metals in columbian-tantaliferous placers in the Issia region. This study is therefore based on the contribution of x-ray fluorescence in the characterization of Nb-Ta placers in the Issia region by the analysis of rare metals in the surrounding formations. This technology provides real-time decision support for operational decisions in the field (exploration, mining), offers a cost-effective alternative to conventional laboratory analysis programs, and effectively addresses remote or difficult field conditions. The ability to rapidly collect large numbers of samples and replicate analyses facilitates the acquisition of higher data density.

The southern part of the Toumodi-Fètêkro greenstone belt is located in central-southeastern Côte d'Ivoire. The lithologies encountered in the felsic rocks can be subdivided in to three units corresponding to volcanic lavas (dacites, rhyodacites and rhyolites), pyroclastics rocks (ignimbrites) and granitoids (granodiorites and granites). All of these lithologies have been generally foliated and metamorphosed in to greenschist facies. Geochemical data show that these felsic rocks are metaluminous to peraluminous, calc-alkaline and have characteristics of magmatic arc rocks (TiO2 < 2 %). The dacites are sodic and the granitoids are “I” Type. Geochemical trends show a possibility of mixing due to the existence of a small Archean legacy component.