Publications scientifiques
Bernard Tassongwa
Autres affiliations : Université de Dschang
D. Njoya
Narcisse Jeudong
Charles Nkoumbou* (Auteur correspondant)
Daniel Njopwouo
François Eba
Comptes Rendus Géoscience
Field description and sampling along two pits, granulometry, Atterberg limits, mineralogical (XRD, FTIR, DSC & TGA) and geochemical analyses of the Balengou clays help to determine their characteristics and the genesis of the deposit. The mineralogical composition is comprised of halloysite–kaolinite, quartz, montmorillonite, hematite, anatase, feldspar, zircon, chromite, and apatite. Gibbsite and illite occur at the shallow and deep depth, respectively. Dikes of sand-poor clays contain also cristobalite and tridymite. Pairs of elements Rb–Ba, Rb–Sr, Nb–Ta, Ta–Zr, TiO 2 –Zr display good positive correlations ( R 2 > 0.85). REE patterns are highly fractionated (La N up to 3312, La N /Yb N : 19–10) and are marked by deep Ce and Eu negative anomalies. Immobile element canonical ratios indicate that the protoliths were commendite/pantelerite, rhyolite and dacite, or their plutonic equivalents. Mineralogical and geochemical features lead to the suggestion that the clays derived from an advanced argillic hydrothermal alteration.
