Petrographic and structural characteristics of the pozzolanic formations and associated rocks in the Brobo area, northern part of the Fêtêkro belt, central Côte d’Ivoire: Implications for potential pozzolan exploitation

The Brobo area, located in the northern Fêtêkro Belt within the Baoulé–Mossi domain of the West African Craton, offers significant potential for understanding crustal evolution and developing natural pozzolanic resources. Despite growing industrial interest, the geological and structural controls of pozzolan occurrences in this region remain poorly constrained. This study combines petrographic and structural analyses to characterize the volcanic, plutonic, and metamorphic rocks associated with pozzolanic materials and to assess their exploration significance. Field and microscopic investigations reveal that the area is dominated by acid to intermediate volcanic rocks—rhyolites, rhyodacites, and pyroclastic formations—spatially associated with granitoid intrusions (granite, granodiorite, tonalite) and minor quartzites. The pyroclastic facies display microlitic to porphyritic textures and mineral assemblages (quartz, feldspar, sericite, epidote) comparable to recognized natural pozzolans. Structurally, two deformation regimes are identified: ductile (N010°–N040° foliations and shear bands under NE–SW compression) and brittle (N070°–N110° faults and en-echelon quartz veins). These features correspond to the regional Birimian tectonic pattern, indicating syn- to late-Eburnean emplacement. The mineralogical and textural characteristics of the pyroclastic formations suggest favorable pozzolanic reactivity, highlighting the Brobo area as a promising target for expanding Côte d’Ivoire’s pozzolan exploitation.