Ground Magnetic Prospecting in Parts of the Calabar Flank Sedimentary Basin and Environs, South-South Nigeria

Abstract

The Calabar Flank sedimentary basin has remained relatively unexplored using potential fields.               In this study ground, magnetic data was acquired covering about three-quarters of the                         Calabar Flank sedimentary basin. Twenty-five traverses were acquired along major communities, each line covering about 4.5 km-5.0 km with station interval data collected at 0.2 km. The acquired field data was processed using both manual and computer software programs which include reduction to pole, polynomial filtering and horizontal gradient magnitude techniques. The results of the analysis indicate both deep and shallow seated anomalies with structures from depth computation which represented Horst and grabens structures in areas of shallow and deep sediments thickness accumulations. The manual depths computation from Stanley’s 77, Petters half-width, and maximum slope methods indicate shallow depth ranging between 0.4 km–1.5 km between Ekprikang and Calabar, while the Creek town areas vary in depths between 1.6 km – 2.0 km these results collaborated with the horizontal gradient magnitude depths estimates which are more reliable indicating the horst structures with depths between 0.5 km–1.5 km around Calabar toward Ikang and the grabens with depths ranging between 2.0 km – 5.0 km between Creek Town and Okoyong. The study reveals that the Calabar flank sedimentary basin has sediment thickness good enough for further investigation of hydrocarbon deposits.