Tectonic Controls on Sedimentation in the Abakaliki Anticlinorium, Ebonyi and Cross River States

The Abakaliki Anticlinorium is a prominent structural feature of the Lower Benue Trough whose origin and influence on Cretaceous sedimentation patterns remain debated, with competing models emphasising wrench tectonics versus thrust inversion producing divergent predictions for hydrocarbon trap geometry. This study investigates the tectonic controls on Cretaceous sedimentation in the Abakaliki Anticlinorium by integrating detailed structural measurements, sedimentary facies analysis, and published geochronological data from exposures in Ebonyi and Cross River states. Structural mapping at twelve outcrop localities documented fold geometry, fault orientations, and kinematic indicators that constrain the deformation history. Stratigraphic sections in the flanking Eze-Aku and Nkporo formations were logged to identify syntectonic sedimentation signals such as growth strata, lateral thickness variations, and facies changes attributable to structural topography. Published detrital zircon geochronology data were reanalysed using maximum depositional age calculation methods to refine provenance and timing constraints. Seismic profile interpretations from published basin analyses were digitised and reinterpreted in the context of the new structural data. The study finds field evidence for a wrench component in the deformation of the anticlinorium that is inconsistent with purely compressional models, with implications for the structural style of associated hydrocarbon traps. Keywords: Abakaliki Anticlinorium, tectonic controls, Cretaceous sedimentation, structural geology, Benue Trough.