UFR Sciences de la terre et des ressources minières, Laboratoire de géologie, ressources minérales et énergétiques, Université Félix Houphouët Boigny, Abidjan, 22 B.P. 582 Abidjan 22, Côte d’Ivoire
The study area is located northwest of Toumodi in the Toumodi-Fètêkro volcanic belt. This work would be a contribution by petrography and structural, to a better knowledge of Zaakro Birimian formations area. The macroscopic and microscopic petrographic study showed that the study area contains metavolcanic rocks, volcano-sedimentary rocks associated to an orthoschist. The metavolcanic formations composed of meta-andesite, metarhyodacite and meta-rhyolite, massive, schistosed or sheared, and volcano-sedimentary formations composed of pyroclastic, volcanic breccias, cinerites these two formations associated to an orthoschist. The texture and mineralogical composition of the rocks have changed. The rocks have undergone deformations are metamorphosed and the original minerals were transformed into secondary minerals (epidote, chlorite, amphibole, carbonates). At the structural level, two deformation mechanisms are highlighted ductile shearing and brittle. The major directions of veins and fractures are ENE-WSW. The abundant presence of sulphides in samples characterized hydrothermal alteration and might indicate the presence of gold mineralization. The formations of ZAAKRO was implemented following two types of volcanism: A basic effusive volcanism generating andesites, and acid generating rhyolites and rhyodacites; Explosive volcanism at the origin of the formation of pyroclastic (volcanic breccias and cinerites). They have subsequently undergone a regional metamorphism of low degree corresponding togreen schist facies.
The northern zone of Bouaflé is located in the central part of the Bouaflé furrow, in the center of Côte d’Ivoire. This zone being highly lateritized, as in all tropical climate zones, a mapping from the regolith with a view to improving knowledge of the geology of the central part of the Bouaflé furrow was initiated. It was done using remote sensing and survey data carried out in the area. Thus, it emerges from this study that the regolith of the study area comes from the supergene alteration of the various geological formations observed and is characterized by a deep alteration profile with an average thickness of approximately 30 m with a spatial distribution of relict regolith, erosion, deposition as well as surfaces affected by widespread lateritization.