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The aeromagnetic anomalies existing in the Deng Deng – Garga Sarali region in Eastern Cameroon were filtered for a structural study of the region’s subsoil. This study presents the results of lineaments and fractures extracted by aeromagnetic image processing methods and compared with scientific data to obtain potential terrain models in the study area. The methodological approach used is based on the filtering of aeromagnetic image by using the analytical signal, the Euler deconvolution, and 2D3/4 modeling, to establish the maps of the lineaments and faults of the study area and their characteristics, and also to propose three models from three previously chosen profiles. Analytical signal and Euler deconvolution techniques have been applied to aeromagnetic anomalies to highlight the relationship between the depth and the source of magnetic anomalies, two parameters whose importance in geoexploration and modeling of the body is essential. We identified the potential contacts by interpretation of the deep Euler anomalies, these are highlighted on the basis of a certain similarity between the maps of the total magnetic field, the map of the analytical signal, the map of the maxima of the gradient horizontal, and geological map. Euler’s map of solutions correlates well with the edges of certain superficial and deep causative bodies.

The aim of this study is to investigate crustal structures from East Cameroon, using aeromagnetic data. The modeling of aeromagnetic data is conducted using the Oasis Montaj 8.0 software. The total magnetic intensity map reduced to the equator (RTE-TMI) shows important anomalies features, namely, the Northern East magnetic anomalies of high amplitude, the Southwest where very low values of the magnetic intensity were observed, and a corridor with negative values relatively high, separating the anomalies. The horizontal gradient map shows on the one hand brittle and folded structures carried out in the area of study and on the other hand various rectilinear, narrow, and short-wave anomalies that can be classified as a family of little faults. The maxima observed on the RTE-TMI maps are correlated to intrabasement contacts; and the map derived from Euler’s solutions permitted to evaluate the depth of the geological accidents observed from the other filters. This map also reveals new faults with a depth greater than 5000 m. The lineaments identified in the Southwestern part could be linked to the Pan-African orogeny and seem to correspond to deep-seated basement structures, which are referred to the tectonic boundary between Congo Craton and the Pan-African orogeny belt. A 23/4-D modeling confirmed the observations derived from the RTE-TMI and HGM maps analyses. It shows intrusive bodies composed of gneiss and porphyroid granite and some domes with their roof situated at various depths not exceeding 1800 m from the surface. The structural map of the study area shows the trending of the structural features observed, namely, NE-SW, NW-SE, ENE-WSW, and WNW-ESE, respectively, while the E-W and N-S are secondary orientation of the observed tectonic evidence. Moreover, circular anomalies observed over the area are assimilated to intrusions of high magnetic materials or to granitic domes.

In the Pitoa-Figuil area (Northern Cameroon), an interpretation of aeromagnetic data was conducted. The aim of this investigation was first to emphasize lineaments hidden under geological formations and secondly to propose two 2.75D models of the subsurface structures. Different magnetic data processing techniques were used, notably horizontal gradient magnitude, analytic signal, and Euler deconvolution. These techniques in combination with the 2.75D modelling to the aeromagnetic anomaly reduced to the equator permit to understand the stratification of the deep and near surface structures, which are sources of the observed anomalies. We managed to put in evidence and characterize 18 faults and some intrusive bodies. According to Euler's solutions, anomaly sources go up to a depth of 5.3 km. [ABSTRACT FROM AUTHOR]

A quantitative interpretation of aeromagnetic data is conducted in the Ebolowa-Djoum area. The aim of the study is to estimate magnetic and geometrical parameters of the causative bodies using spectral analysis and 2.5 modeling. In addition an indicative evaluation of the volume of magnetic material is done using geoinformation mapping tool. The techniques are applied to three N-S profiles (P1, P2 and P3) that cross three anomalies at Kamélon (P1), Ngoa (P2) and between Djoum and Olounou (P3). The application of the techniques cited above has given the following results: (1) Magnetic bodies identified have susceptibility with a range that coincides to iron formations such as magnetite and haematite; (2) the depth to the top of the iron formation that produce the observed magnetic anomalies varies from 88 m to 109 m at Kamélon, 32 m to 670 m at Ngoa and 50 m to 580 m along the profile P3; (3) the depth to the foot of that formations is from 614 m to 1240 m at Kamélon, 802 m to 965 m at Ngoa and 250 m to 1340 m along P3; (4) an E-W extent (strike) of iron formations is 12000 m at Kamélon, 1600 m to 12000 m at Ngoa and 12000 m in the P3 profile; (5) a N-S extent (width) of iron formations ranging from 2390 m to 77470m at Kamélon, 3680 m to 9600 m at Ngoa and 1540 m to 13140 m in the P3 profile; (6) indicative volume value of that iron formations varies from 10.1 km3 to 16.3 km3 at Kamélon, 0.7 km3 to 8.7 km3 at Ngoa and 1.20 to 18.0 km3 along profile P3. [ABSTRACT FROM AUTHOR]

The subsurface structures in a part of the Congo Craton in south-eastern Cameroon, between the latitudes 2° to 3° N and longitudes 13° to 15° E, has been estimated by the interpretation of aeromagnetic data. Magnetic survey is used to delineate magnetic lineaments, analyze its relationship to the tectonic fabric and to estimate the depth of perturbing body source, probably granitic intrusion along one profile selected on the total magnetic intensity reduced to the equator (TMI-RTE) map by means of forward modelling and inversion constrained by surface geology and results from Euler deconvolution analysis method. Determination of the magnitude maxima of the first vertical derivative (FVD) of the residual field reduce to the equator allowed a map to be produced showing various aeromagnetic lineaments interpreted as the fault system of the studied area. Particularly, looking at the center of the structural map, we find that these structures are associated to long-wavelength anomalies, suggesting that its should be connected with large-scale structural deformation. The pseudo- gravity map shows the extension of the tillitic formations on the geological map. Our results confirms the morphological difference and the tectonical subdivision into two tectonic sectors corresponding to the Congo Craton in the south, Pan-African in the north and also helped identify the tectonic boundary separating them at depth. [ABSTRACT FROM AUTHOR]