Application of high-resolution aerogravity data for lithostratigraphic and depth characterization of the Anambra Basin, Southeastern Nigeria

Aerogravity anomalies in the Anambra Basin, Nigeria, were analysed for lithostratigraphic and depth characterization. The Bouguer gravity data were enhanced, gridded, and the regional anomalies isolated from the residual anomaly by a second-order polynomial fit. The residual anomalies were interpreted by contouring, modelling and depth estimation using inverse and forward modelling and standard Euler deconvolution operation of the Oasis Montaj Software. The contour map shows low gravity values of−19.5 mGal to zero for subsurface formations in the western, central and north-eastern parts of the regions indicating formations with low density mass. High density subsurface formations with gravity values up to 24.1 mgals are found in the northern, south-eastern, eastern and north-eastern parts of the region. The subsurface formation hosts syncline and anticline structures with faults. Sedimentary depths range from 342 m to 9260 km. This also reflects the depth to basement in the region. These sedimentation depths imply favourable hydrocarbon sources and habitats as is common in the country.