Detection and characterization of lineaments using gravity data in the south-west Cameroon zone: Hydrogeological implications

In Cameroon, the drying up of wells and boreholes during the dry season is characterized by a lack of knowledge about the surface structures of the subsoil and the spatial distribution of groundwater. In this study, we propose to use gravity data to detect and characterize the surface structures of the south-west (SW) Cameroon and to analyze their hydrogeological implications. The application of the normalized standard deviation method on the data obtained from the stable downward continuation of the Bouguer anomalies led to the detection of 71 lineaments that characterize the tectonic events of the study area. The statistical analysis of the lineament directions shows that the near-surface structures were mainly affected by a tectonic of direction east-west followed by that oriented SW-north-west. These two directions are consistent with the megastructures in the region like the Ngoro-Belabo Shear Zone and the Sanaga Fault stretching from the Gulf of Guinea to the Central African Republic. In addition, the application of the Euler deconvolution method permits us to evaluate the interval in which lies the depth of each lineament hosting Euler solutions. The analyses showed that 12 lineaments, whose roof depths are between zero and 250 m, are very favorable for hydrogeological prospecting.