TITLE:
Contribution of New Geological and Aeromagnetic Data to Update Lithostructural Map of Daloa Region (Central-Western Côte d’Ivoire)
AUTHORS:
Aristide Ghislain Beugré Dago, Ehui Beh Constantin Aka, Ziandjêdé Hervé Siagné, Sawadogo Saga, Kouadio Florentin Tani, Abé Parfait Sombo, Zié Ouattara, Yacouba Coulibaly
KEYWORDS:
Geophysics, Airborne Magnetic Data, Petrography, Structures, Granitoids, Daloa, Ivory Coast
JOURNAL NAME:
Open Journal of Geology,
Vol.16 No.10,
October
28,
2026
ABSTRACT: This article is a contribution to the understanding of the structuration of the West African Craton (WAC) through an integrated analysis of geophysical and petro-structural data from the Daloa region in west-central Côte d’Ivoire. Airborne magnetic data were used for mapping a regional structure, as this is a forested region. Fourier domain processing (Reduce To Equator, Analytical Signal, and Tilt derivative) was used to produce maps highlighting the main regional structures, which were then confirmed in the field. This method made it possible to define the geometry of the different massifs and the contacts between the different lithological units. The Daloa region is made up of calc-alkaline granitoids (granites and migmatites) and schists elongated in directions ranging from N20˚E to N60˚E, with subvertical dips (60˚SE to 80˚SE). The massifs are traversed by a network of fractures oriented E-W, NW-SE, NE-SW, which correspond to the direction of the numerous aplite, pegmatite, tourmalinite, and quartz veins observed there. Brittle deformation is characterized by the formation of vein structures or strike-slip faults. These directions are consistent with the lineament directions observed on geophysical maps. The structuring of this region occurred in four main phases recognized at the scale of the West African Craton: a NNW-SSE synmagmatic compression phase (D1), followed by an early NE-SW extensional phase (D2) during a period when the massifs still retained some ductility. Next comes a N-S compression phase (D3) responsible for numerous shears, and finally a late tensile phase (D4) leading to the reactivation of the faults from phase D2.