One-dimensional spectral analysis of aeromagnetic anomalies and Curie depth isotherm in the Anambra Basin of Nigeria

Abstract

One-dimensional spectral analysis of aeromagnetic data over the Anambra Basin, which is a subsidiary depression within the Benue Trough of Nigeria, was made to map the sedimentary thickness variations and the Curie temperature isotherm. Sedimentary thickness (depth to the basement) varies between 0.9 and 5.6 km, while depth to the Curie temperature isotherm varies between 16 and 30 km below the mean sea level. The result also shows that the Curie temperature isotherm within the basin is not a horizontal level surface, but is undulating, and the geothermal gradients associated with it range between 20 and 35 °C/km.