0000000000433547
AUTHOR
C. O. Ajayi
A magmatic failed rift beneath the Gongola arm of the upper Benue trough, Nigeria?
Abstract A magnetic anomaly map of the Gongola arm of the upper Benue trough was compiled from existing half-degree sheets of the upper Benue trough. The map is dominated by an elongated NE–SW magnetic low anomaly that stretches over a 100 km distance and has an average width of about 20 km. A combination of Werner deconvolution and forward modeling techniques on selected profiles across the major NE–SW anomaly lead to the conclusion that the anomaly may be caused by predominantly mafic rocks at depths of between 6 and 10 km, well below the base of the sediments, which are generally not more than 4.5 km thick. The presence of large and continuous bodies of mafic rocks indicated by these res…
Gravity Anomalies Over The Gongola Arm, Upper Benue Trough, Nigeria
A regional gravity survey of the Gongola Arm of the Benue trough was carried out with the aim of determining structures of interest. The results of the gravity interpretation showed that the area of study is characterized by negative Bouguer anomalies that trend in the NE-SW direction and range in value from -75 to -15 mGal with an average of -42 mGal. A first order polynomial was used to approximate the regional anomalies in the area. The residual gravity anomaly map shows anomalies that range in value from -32 to +20 mGal. 2.5-D modeling of the residual gravity anomalies suggests that the area has a horst and graben structure, with the grabens being as large as 60 km in width and filled w…