IDENTIFICATION OF DEPTH TO BASEMENT OVER UGEP AND ENVIRONS, CROSS-RIVER STATE, NIGERIA USING SLOPE METHOD ANALYSIS OF AEROMAGNETIC DATA

Abstract

The study aimed at the identification of depth to basement over Ugep and environs, Cross River State, Nigeria, using slope method analysis of aeromagnetic data. The study area covers an estimated area of 55 km by 55 km squared between latitudes 5⁰30’N to 6⁰00’N and longitude 8⁰00’E to 8⁰30’E. The data involved were processed and interpreted using the Surfer-32 software. Seven profiles were taken on the residual anomaly map, which shows the anomalies present. Peter’s Half-Slope method is used to deduce the depth to the basement of the study area. The visual inspection of magnetic maps depicts that the total magnetic intensity ranges from 7820 nT to 8120 nT while the residual magnetic intensity ranges from -140 nT to 160 nT. The area is intensely fractured with major faults trending in NE-SW direction and minor fault tending in the NW-SE direction. The depth to basement obtained using Peter’s Half-Slope method ranges from 0.16 km to 4.8 km with an average of 2.05 km across the study area. The basement map generated revealed the basement configuration as well as the sedimentary thicknesses within the study area. The 3D surface plot of the basement map indicates the presence of depression and uplift. The findings of this study suggest that the study area possesses some requisite characteristics for possible hydrocarbon accumulation within the study area, considering the huge sedimentary thickness in the area.