Structural and Paleostress Analysis of the Afikpo Syncline

Detailed field-based structural, fracture and paleostress analysis were carried out on Cenomanian to Maastrichtian units within the Afikpo synclinorium. 3 fracture sets were isolated from analysis of fracture orientations and field relationships: Pre-folding (JT), Syn-Folding (JS) and Post Folding (JC) fracture systems. Paleostress analysis carried out on these fracture systems using the TENSOR™ software tool (Delvaux & Sperner, 2003) yielded 3 paleostress tensors corresponding to three stress regime periods: A Cenomanian to Turonian transtensional stress tensor with a ENE-WSW direction of maximum extension (SHMIN), a Santonian oblique compressive (transpressional) tensor with NW-SE direction of maximum shortening (SHMAX), and a Campanian to Maastrichtian transtensional tensor with WNW-ESE direction of maximum extension (SHMIN). These tensors are related to the prevailing plate tectonic stress regimes affect the entire Benue trough and the West and Central African Rift System (WCARS).