Mapping, Petrostructural Analysis and Metallogeny of the Natiemboro Geological Formations in the Tortiya Area (North-Central Côte d’Ivoire)

Résumé fourni par la source

This study, which was conducted in the Natiemboro area of the Korhogo Department in north-central Côte d'Ivoire, aimed to improve our understanding of the region's petrography, structure and metallogenesis. To this end, a geological mapping campaign was carried out in combination with rock and soil sampling using satellite imagery. A total of 25 polished sections were prepared for petrographic, microstructural and metallogenic analysis. The mapping reveals four units: a metasedimentary unit consisting of sericite schists and quartzites ; a metaplutonic unit consisting of biotite metagranite, gneiss, and metamicrogranodiorite ; an intrusive unit consisting of fine- and coarse-grained granite ; and a unit consisting primarily of pegmatites. These units are primarily affected by green schist-facies metamorphism and also exhibit hydrothermal (pervasive and vein-type) and meteoric alteration. Pervasive hydrothermal alteration is exemplified by carbonation, sericitisation, chloritisation, epidotisation, silicification and sulphidation, while vein-type hydrothermal alteration is characterised by veins and dykes of quartz, carbonates and quartz-tourmaline. The metasedimentary complex exhibits S1 schistosity, which is oriented NNE-SSW or NE-SW with gentle dips of 40–46°. It is thought that regional NW-SE compression caused this schistosity. The metasedimentary and metaplutonic complexes are traversed by two main left-lateral shear zones oriented N-S and NE-SW, respectively. These shear zones are intersected by left- and right-lateral detachment faults and fractures oriented NW-SW, N-S to NNE-SSW and E-W. The NNE-SSW and N-S vein systems are associated with the shear zones and host gold mineralisation. These veins are mined by illegal gold panners.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.