Magnetic Anomaly Interpretation of the Northern Congo Craton Boundary: Results from Depth Estimation and 2.5D Modeling

摘要

A magnetic-based geophysical study was performed across the southern part of Cameroon to investigate the boundary between the Archean Congo craton and the Pan-African metamorphic belt. Magnetic gradient techniques including Euler deconvolution and Tilt derivative have been applied to an aeromagnetic data profile to determine the depth of sources and their lateral extension. 2.5D magnetic modeling shows that the prominent magnetic positive anomalies observed on total magnetic map of south Cameroon are produced by deep and strongly magnetic bodies under the Pan-African formations mainly an important dyke formation structure with a high susceptibility of 0.041 (SI units), at an average depth of 4148 m and with a lateral extension of about 10 km. These bodies are interpreted to have emplaced at high crustal levels in a continental collision zone and were subsequently metamorphosed at granulite grade conditions, during the Pan-African orogeny about 620 Ma ago.