CHLORITES AND CHLORITIC MIXED-LAYER MINERALS IN PROFILES ON ULTRABASIC ROCKS FROM MOYANGO (IVORY-COAST) AND ANGIQUINHO (BRAZIL)

Y Noack (1) , F Colin (2)

1 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement
2 Laboratoire de Géologie dynamique et Pétrologie de la Surface

Different types of chlorite and related mixed-layer minerals have been found in profiles developed on ultrabasic rocks of Ivory Coast and Brazil. Normal chlorites, with low K and Ni contents, are of hydrothermal origin and are situated at the bottom of the alteration profile. At the top of the profile the mixed-layer minerals are Ni-chlorite/vermiculite, which formed under weathering conditions, or K-chlorite/vermiculite, resulting from the alteration of mica. The Ni-content of the chlorite/vermicufite can reach 10% NiO.

Mots clés: talc-saponite; saponite-swelling chlorite; chlorite-swelling chlorite; chlorite-montmorfllonite; chlorite-smectite; chlorite-vermiculite

Domaines: Minéralogie

Y Noack, F Colin. CHLORITES AND CHLORITIC MIXED-LAYER MINERALS IN PROFILES ON ULTRABASIC ROCKS FROM MOYANGO (IVORY-COAST) AND ANGIQUINHO (BRAZIL). Clay Minerals, 1986, 21 (2), pp.171-182. ⟨10.1180/claymin.1986.021.2.06⟩. ⟨hal-01424705⟩