Seismic Reflection Profiling for Structural Interpretation Beneath the Abakaliki Anticlinorium, Ebonyi State

The Abakaliki Anticlinorium is a major structural feature of the Benue Trough that has attracted considerable interest for its petroleum potential and mineral endowment, yet its subsurface geometry at depth remains poorly constrained. This study interprets two-dimensional seismic reflection profiles to characterize the structural architecture beneath the Abakaliki Anticlinorium in Ebonyi State. Seismic data from the Nigerian Petroleum Development Company archives were reprocessed using KINGDOM Suite software, involving noise attenuation, velocity analysis, normal moveout correction, stacking, and post-stack time migration. Key seismic sequences were identified, tied to available well data, and used to map major reflector surfaces and structural elements. The reprocessed seismic sections reveal a complex fold-thrust system with multiple detachment horizons within the Upper Cretaceous sequence. Anticlinal closures are identified at three stratigraphic levels, with two closures exhibiting four-way dip closure geometry favorable for hydrocarbon trapping. Fault displacements mapped on the seismic sections range from minor growth faults with throws of 50 to 150 m to major compressional reverse faults with throws exceeding 500 m. A basal decollement surface is consistently imaged at approximately 5 seconds two-way travel time, corresponding to an estimated depth of approximately 8 km beneath the anticlinorium axis. Depth-converted structural maps define prospective targets for future appraisal drilling. The study provides a significantly improved understanding of subsurface structure beneath the Abakaliki Anticlinorium, with implications for both hydrocarbon and mineral resource exploration.

Keywords: seismic reflection, Abakaliki Anticlinorium, fold-thrust belt, structural interpretation, Benue Trough