Investigation of the Superficial Structures of the Foumban Area (West Cameroon) Based on Spectral Analysis and 3D Modelling

Abstract

The main objective of this study is to characterise the superficial structures of Foumban area. To achieve this, a sample of data from the gravity map of Cameroon is used to build a new Bouguer map to the studied area. The finite element method is used to separate the Bouguer anomalies into regional and residual anomalies. Given that the signatures of gravity anomalies related to surface structures are perceptible on the residual anomaly map, a qualitative analysis of this map helped to identify three anomaly domains in the north-western, central and north-eastern parts of the studied area. These three anomalies peak at 19 mGal, -24 mGal and 27 mGal, respectively. Spectral analysis is used to obtain the appropriate energy spectrum for different profiles that were selected, to estimate the average depth of the intrusive bodies. Thus, thanks to 3D modelling of the anomalous structures of the crust, a gravimetric interpretation is carried out. This interpretation leads correlatively to the geology of the region to conjecture the presence of sediments (clays, conglomerates, sandstones, sands) in the center of the study area; metamorphic rocks (gneisses, micaschists) and magmatic rocks (granites) responsible for positive anomalies in the rest of the area