Analysis of high-resolution airborne-magnetic data for hydrocarbon generation and preservation potential evaluation of Yola sub-basins, northern Benue Trough, northeastern Nigeria

Abstract

High-resolution airborne-magnetic data acquired over the Yola extension of the northern Benue Trough, northeastern Nigeria, were analyzed to delineate rock distribution, define basement geometry, determine sedimentary thicknesses, and highlight structural framework among others for the hydrocarbon prospect evaluation of sub-basins in the extension. Filtered and refined magnetic intensity data were subjected to Analytic Signal, Horizontal and Vertical Tilt Derivatives and Euler deconvolution depth weighting analyses to enhance various geological features requisite for petroleum prospect evaluation. Sedimentary rock units flanked the northeast and south widely occur in the central part with volcanic rock intrusions delineated within the sedimentary terrain. Extracted lineaments (less than 5 km and up to 45 km) were observed to dominantly follow the established Benue Trough and Yola sub-basin evolutionary trend along the NE–SW and ESE–WNW directions, respectively. Three prominent sub-basins with sedimentary thicknesses in excess of 3 km and width of more than 60 km, separated by basement highs of mostly volcanic intrusions origin, were identified. The occurrence of relatively thick and extensive sub-basins which are underlain by structurally active basement rocks suggests relatively high geothermal gradient for generation of hydrocarbon from organic matter rich source rocks while the generated oil and gas are preserved within intra-sedimentary structural traps created when the basement fractures were reactivated.