A petrographic, mineralogical, and geochemical characterizations of the lateritic hardpans of Bamendjou in the western region of Cameroon

Abstract

A combined petrographic, mineralogical, and geochemical characterization of the lateritic hardpan deposits of Bamendjou was carried out. The purpose was to better understand the process of laterization in a view to facilitate the broad use of this deposit in building applications. The petrographic analysis reveals the presence of protopisolithic, massive, and nodular facies. On the basis of the results provided by X-ray diffraction (XRD), these facies are composed of such phases as gibbsite, goethite, hematite, anatase, and kaolinite. In addition, boehmite has been found in the massive and protopisolithic facies, whereas gibbsite and magnetite frequently occupy the nodular facies. Whole-rock geochemical data indicates that a alumina represents the most abundant oxide in the protopisolithic and the massive facies (46.78–51.63 wt.% and 42.85–43.45 wt.%, respectively). It is followed by relatively high content of iron 12.93–18.33 wt.% and 23.43–23.78 wt.%, respectively) accompanied by very low contents of silica 1.44–2.75 wt.% and 2.44–3.99 wt.% of SiO2 respectively) and titanium 3.70–47.0 wt.% and 4.00–5.30 wt.%, respectively). Iron is the most abundant chemical element in the nodular facies since it ranges from 49.64 to 58.58 wt.%. The petrographic, mineralogical and geochemical geochemical (especially the high iron content) features suggest that the lateritic duricrust of the Bamendjou area have good potential to be utilized in stonework in buildings (bricks).