[01] Onyishi George Emeka, Department of Industrial Physics, Enugu State University of Science and Technology, Enugu, Nigeria. [02] Ugwu Gabriel Zeruwa, Department of Industrial Physics, Enugu State University of Science and Technology, Enugu, Nigeria. [03] Okonkwo Austin, Department of Geology and Mining, Enugu State University of Science and Technology, Enugu, Nigeria.

The aeromagnetic data over Lafia, Akiri, Makurdi and Akwanga, of the Middle Benue Trough of Nigeria were interpreted by forward and inverse modelling techniques in order to determine the depth to basement and the type of mineralization prevalent in the area. Oasis Montaj and PotentQ software were used for the data reduction and interpretation. The regional anomalies were separated from the total magnetic intensity (TMI) to obtain the residual fields using first order polynomial fitting. The magnetic anomalies were modelled by prismatic and ellipsoid bodies. The magnetic susceptibility of the bodies after forward and inverse modelling of profiles 1-5 were respectively 0.0400, 0.0003, 0.0002, 0.0001 and 0.0250; with respective depths of 4650, 1160, 2420, 980 and 3420 m. The indicated magnetic susceptibilities of these bodies suggest that they are igneous or metamorphic intrusions of basic to intermediate composition. These magnetic susceptibilities are associated with occurrence of minerals such as pyrite and graphite and rocks such as granite, limestone, schist, gnesis and marble. Maximum depth to basement was recorded around Akiri in the north-eastern part of the study area. The prospect for hydrocarbon accumulation is higher around the north-eastern part of the study area than at the other parts.

Aeromagnetics, Forward and Inverse Modelling, Intrusions, Magnetic Susceptibility, Basement Depth and Mineralization

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