TITLE:
Structural Analysis of Deformation in the Metasediments of the Dimbokro-Abengourou Trough, Central-Eastern Côte D’Ivoire
AUTHORS:
Diakite Sekou, Allialy Marc Ephrem, Pria Koffi Kossonou Jean-Marie, Adingra Martial Pohn Koffi, Koffi Yao Augustin
KEYWORDS:
Dimbokro, Bassin of Comoe, Dimbokro-Abengourou, Metasediments, Deformation, West African Craton
JOURNAL NAME:
Open Journal of Geology,
Vol.16 No.9,
September
21,
2026
ABSTRACT: The Dimbokro-Abengourou Birimian Trough is a volcano-sedimentary unit in the central-eastern part of Côte d’Ivoire, forming part of the Proterozoic domain of the West African craton. It consists mainly of metasediments, schists, metagrauwackes and quartzites, intruded by granitoids. This study aims to characterise, using teleanalytical data and field structural analysis, the deformation mechanisms and phases recorded in these formations, particularly in the Dimbokro area. Interpretation of satellite imagery and the digital elevation model has enabled the mapping of the structural lineaments of the rift, dominated by a NE-SW to NNE-SSW trend, parallel to the extension of the belt. In the field, the metasediments show an initial ductile deformation phase D1, transpressive, marked by S1 flow schistosity oriented N00˚-N15˚ and dipping subvertically to the east, associated with left-lateral C1 shear planes oriented N170˚ forming S/C structures, as well as symmetrical sinuses oriented N00˚-N10˚. A second, more subtle phase D2 develops a crenulation schistosity S2 oriented N110˚, which overlies and folds S1 in the finest-grained facies. These two ductile phases are followed by a brittle deformation phase D3, manifested by E-W-trending joints, left-lateral and right-lateral detachments, and the left-lateral detaching Dimbokro fault oriented N10˚ with a subvertical dip, as well as by quartz veins oriented N-S to NNE-SSW or E-W to ENE-WSW. Late-stage E-W doleritic veins mark the conclusion of the region’s tectono-magmatic history. These results, when compared with those obtained in other Birimian belts in the southern part of the West African craton, fit within the regional pattern of the Éburnian orogeny and confirm the polyphasic nature of the deformation in the Dimbokro-Abengourou trough.