Interpretation of aeromagnetic data of Idah area in north central Nigeria using combined methods

Abstract

Aeromagnetic data of Idah area (sheet 267), north-central Nigeria, has been interpreted by applying source parameter imaging (SPI), Euler deconvolution and forward and inverse modeling methods. Quantitatively, depth estimates obtained by employing SPI have shown minimum to maximum depth to anomalous source at 57.591m to 664.841m. Applying Euler deconvolution for various structural indices (SI), the depth obtained for SI=1, ranges from 5.6m to 197.6m, 22.0m to 204.7m for SI=2 and for SI=3, the depth to magnetic source obtained ranges from 38.0m to 205.5m. The results from forward and inverse modeling for profiles 1, 2, 3, 4 and 5 indicate depths of 95.6m, 103.9m, 477.5m, 1239.8m and 76.8m respectively. From the results of susceptibility values; the result obtained from profile 1 with susceptibility value of -0.0175 suggests that the body is associated with non-magnetic sedimentary deposits. Profile 2 with a susceptibility value of 0.07 is typical of basic igneous rock; gabbro and basalts. The results for profiles 3, 4 and 5 having susceptibility values of 0.01 to 0.013 are typical of intermediate igneous rocks; diorite and andesite.