Scientific publications
Gilbert François Ngôn Ngôn* (Corresponding author)
Jacques Étamé
Marie Joseph Ntamak-Nida
Cécile Olive Mbesse
Joël Simon Mbaï
Élie Constantin Bayiga
Martine Gérard
Other affiliations: Institut de minéralogie, de physique des matériaux et de cosmochimie · Institut de Recherche pour le Développement
Comptes Rendus Géoscience
Major and trace element composition of iron duricrusts including clayey material samples and biostratigraphy of the Missole I outcrop from the Paleocene–Eocene N’Kapa Formation in the Douala sub-basin of Cameroon were used to infer the palaeoenvironment and relative age of the iron duricrusts. Iron duricrusts and clayey materials are essentially kaolinitic and smectitic and are generally siliceous and ferruginous (iron duricrusts) or siliceous and aluminous (clayey materials). These materials have high Chemical Indices of Alteration (CIA = 86.6–99.33%). The negative Eu anomalies with high (La/Yb) N shown by iron duricrusts and clayey sediments are essentially derived from silicic or felsic parent rocks when fractionated chondrite-normalized REE patterns also indicate felsic or silicic parent rocks. The Missole I iron duricrusts have a post-Thanetian age according to the relative age of claystones (Thanetian) and were formed after the deposition of sedimentary materials in an anoxic low-depth marine environment with eutrophication of surface water, and may have been exhumed and oxidized under arid climate.
