Zié Ouattara^1,, Gnamba Franck Emmanuel Gouédji¹, Gbélé Ouattara², Koffi Olivier Kanga¹, Olivier Moro Boffoué¹, Yacouba Coulibaly³

The Birimian furrow of Toulépleu-Ity located in the Archaen domain of Côte d'Ivoire is at the heart of various mining projects. Thus, this study is initiated in three localities namely Toulepleu, Zogouiné and Guéya in order to elucidate the petrography and deformations. The data analysis and interpretations undertaken at the University of Man allow to learn deeply this Birimian furrow. Petrographically, two main groups of rocks are identified: (i) magmatic comprising granodiorite, microgranodiorite, tonalite and dolerite, (ii) metamorphic composed of gneissisified granodiorite, metatonalite, metaargilite, metadolerite and various schists (chloritoschists). Argillite is the main sedimentary rock. The metamorphism evolves from greenschist to amphibolite facies overprinted by the chlorite - green hornblende association. Eburnean magmatic event has been ended with the settlement of dolerite which appears metamorphosed and fractured suggesting the reactivation of the Eburnean event. Pervasive hydrothermal alteration is marked by mylonitized quartz veins. Structurally, three main orientations are expressed : N-S, NE-SW and NW-SE. Ductile deformations are observed in schists, metatotalites and metasediments. The schistosity planes have a dip of 44°S. Brittle deformations have a preferential NE-SW orientation and are associated with quartz plus tourmaline veins showing by that their auriferous potentiality. These structures are part of a shearzone of N080° that can serve as a target for gold exploration in the area.

Toulepleu-Ity birimian furrow, Archaen, petrography, deformation, Côte d’Ivoire