This study is a contribution to the planning of hydrocarbon exploration program of the Koum sedimentary basin in North Cameroon. 3D modeling of WGM2012 gravity data derived from EGM2008 geopotential model in the Koum basin was used together with existing geological and spectral analysis information to give structural picture of the basin. The 3D model of the Koum basin confirms that the basin is developed as a half graben bounded by sub-vertical faults. The thickness of the Cenozoic sediments is about 1.5 km in the eastern part and reaches 4.5 km in the western part of the basin. Gravity lineaments computed by multi-scale analysis revealed structural trends in the E–W, NW–SE, NE–WS and N–S directions. The faults in the sedimentary terrain reach 6 km depth and have a predominant NW–SE trend with E–W trending faults along the contact between the sedimentary section and the basement complex in the northern edge.

This study investigates the dominant orientations of lineament features and the relationship between these trends and the spatial orientation of tectonic structures in the transition zone of the Congo craton and the Pan African belt in South Cameroon area. Landsat 8 OLI/TIRS and hill-shaded images, constructed from 30 m-resolution SRTM-DEM data, were used for automatically extracting and mapping geological lineaments. Lineament features were analyzed by means of azimuth frequency and length density distributions. Three major sets of lineaments trending W–E, ENE-WSW and WNW-ESE are identified in the South Cameroon area. These trends are probably related to repeated reactivation of pre-existing crustal structures during Eburnean and Pan-African tectonic episodes. The lineaments were formed under the compressional tectonic stress regimes generated during these tectonic events.

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Groundwater is the major water reserve in the present context of global warming-related droughts that appear to be more intense in hard rock terrains. The use of Geographical Information Systems (GIS) and Remote Sensing (RS) technologies are increasingly beneficial to groundwater research, by allowing for low cost and larger-scale high-resolution mapping compared to conventional hydrogeological exploration methods. This study aimed at developing a high-resolution map of potential groundwater recharge (GWRpot) zones for the drought-stricken Banka hard rock terrain, straddling the Cameroon Volcanic Line (CVL). Shuttle Radar Tomography Mission (SRTM)-30m and Landsat 8 satellite images constituted the main data source that was ground-truthed through field mapping and used to produce various thematic GIS layers: geology slope, aspect, land use & land cover, drainage density and lineament density of spatial resolution 16m x 16m. The layers were each attributed a fixed score and weight to groundwater recharge, computed using Multi-Influencing Factor (MIF) and Analytical Hierarchy Process of Multi-Criteria Decision Analysis (AHP-MCDA) techniques. Lastly, a Weighted Overlay Analysis was done using the layers to produce the GWRpot zones for the study area. The resulting map shows that 60% of the study area, covering the south, west-northwest and the north-northeast portions of the map have moderate to very high recharge potentials. This result is particularly useful for groundwater targeting in the area and demonstrates the effectiveness of the method in hard rock terrains where traditional methods have been less efficient in properly delineating groundwater recharge zones. Article highlights Groundwater is generally the safest and most reliable source of water in water scarce environments, and forms when surface water goes into the ground. More areas where water can enter the ground means more chances of getting enough groundwater. Conventional ways of knowing these areas are time consuming and costly, whereas RS and GIS-based methods are less costly and use lesser time. We used the RS, GIS, high-resolution field mapping and statistical methods of blending several factors to produce the potential groundwater recharge zones on a part of the hardrocks of the CVL, that shows 60% of the study area, covering the south, west-northwest and the north-northeast portions of the area have moderate to very high recharge potentials.

Gravity data in the southern Cameroon are interpreted to better understand the organization of underlying structures throughout the northern edge of the Congo craton. The Bouguer anomaly maps of the region are characterized by an elongated SW-NE trending negative gravity anomaly which correspond to a collapsed structure associated with a granitic intrusion beneath the center of the region and limited by fault systems. We applied 3-D gravity modelling and inversion in order to obtain the 3-D density structure of the area. Our result demonstrated that observed gravity anomalies in the region are associated to tectonic structures in the subsurface. The resulting model agrees with the hypothesis of the existence of a major continental collision zone between the Congo Craton and the Pan-African belt. The presence of deep granulites structures in the northern part of the region expresses a continental collision.