The present study integrates high-resolution aeromagnetic and radiometric datasets to delineate new mineral prospectivity zones within and around Mandjap I, a densely vegetated and logistically challenging tropical region located in west-central Cameroon. The study area belongs to the Nyong Complex of the northwestern Congo Craton, a geologically complex domain marked by polyphase tectono-metamorphic evolution and significant structural reworking. In such environments, conventional geological mapping is often hindered by dense forest cover and limited outcrop exposure, making airborne geophysical methods particularly valuable for regional litho-structural investigations and mineral prospectivity mapping (MPM). To enhance the structural and lithological interpretation of the area, the Centre for Exploration Targeting (CET) grid analysis was applied to the reduced-to-pole aeromagnetic dataset. The analysis identified 1,043 magnetic lineaments with lengths varying from 113.13 m to 2,880.27 m. Statistical and spatial analyses reveal a dominant ENE–WSW structural orientation, accompanied by subordinate NE–SW, NNE–SSW, and E–W trends, reflecting the influence of multiple tectonic deformation phases. Zones characterized by high lineament density and structural intersections correspond closely with the Nyong Complex known for intense tectonic deformation and metamorphic overprinting. These structurally complex domains are interpreted as favorable pathways for hydrothermal fluid circulation and mineral deposition. The integration of aeromagnetic-derived structures with radiometric signatures revealed strong spatial relationships between structural discontinuities and hydrothermal alteration zones. In particular, the K/eTh ratio proved highly effective in delineating potassium enrichment associated with hydrothermal alteration processes linked to mineralization. Fault intersections and fracture corridors systematically coincide with anomalous radiometric responses, suggesting structurally controlled hydrothermal alteration. Furthermore, the ternary radiometric composite (K, eTh, eU) enabled the refinement of the regional geological framework by discriminating previously unrecognized litho-structural units and improving lithostratigraphic interpretation across the Mandjap I region. The combined geophysical approach significantly enhanced lithological discrimination, enabling the identification and spatial delineation of granitized gneiss, embrechitic gneiss, migmatites, and high-grade metamorphic gneissic formations. In addition, eleven priority hydrothermally altered zones were identified as highly prospective targets for future exploration. These zones corroborate major structural corridors and radiometric anomalies, emphasizing the critical role of tectonic controls in ore-forming processes within the study area. Overall, the results substantially enhance the geological understanding of the Mandjap I region by providing new insights into its lithological variability, structural architecture, and hydrothermal evolution. The methodological framework developed in this study demonstrates the effectiveness of integrating aeromagnetic and radiometric datasets for MPM in highly vegetated tropical terrains and offers a robust exploration strategy for structurally complex and poorly exposed geological environments.
Aeromagnetic and aero-radiometric methods have been successfully used to locate zones of mineralization potentials in Ganmo–Amoyo–Ojoku areas by mapping lithology, structures and hydrothermal alteration regions for industrial purposes. The data, sheet 223-Ilorin on a scale of 1:100,000 were obtained from the Nigerian Geological Survey Agency (NGSA) at a height of 80 meters along a series of NE-SW flight lines spaced 500 m interval. The Total Magnetic Intensity data was gridded at 100 m then reduction to the magnetic equator (RTE) was applied to center magnetic anomalies over their respective magnetic source bodies with the aid of Oasis Montaj™ software. Other enhancement techniques applied are first vertical derivative (FVD), analytic signal (AS) and tilt angular derivative (TDR). In addition, the potassium to equivalent thorium (K/eTh) ratio and ternary radiometric maps were revealed to support the delineation process. The interpreted map for magnetic lineaments by delineating the anomaly maxima mostly observed in the southern and eastern portions of the study area extending from Orogun to Apala and Alaya with continuous linear contour patterns. The lineaments range in lengths from 50 m to 1000 m while the orientations range from NE-SW to NW-SE. The equivalent ratio of potassium-thorium and ternary map revealed lithological units and hydrothermal alterations within the basement complex. From this study, volcanic intrusions, lineament structures, and hydrothermal alteration zones were delineated.
Folorunso Owolabi Wahab, J. Ajadi, G. Omolaiye et al.· FUDMA Journal of Sciences· 0 citations
We aim to map fracture networks in the Lobo watershed at Nibéhibé using the interpretation of aeromagnetic data. The methodology involved processing the aeromagnetic dataset with Oasis Montaj software, including preliminary corrections, removal of the International Geomagnetic Reference Field, and interpolation onto a regular grid. To enhance the structural analysis, several filtering techniques were applied, including reduction to the equator, horizontal and vertical derivatives, tilt-angle transformation, and upward continuation. These processing steps enhanced the contrast of magnetic anomalies and improved the delineation of geological discontinuities. Interpretation of the processed maps led to the identification and mapping of 88 major fractures. Directional analysis revealed two dominant fracture trends, NW–SE and NE–SW, reflecting regional tectonic controls associated with the evolution of the West African Precambrian basement. The results highlight a well-developed fracture network that plays a significant role in the structural framework of the watershed and in controlling groundwater flow. Overall, we demonstrate the effectiveness of aeromagnetic data processing techniques for structural mapping and hydrogeological exploration in crystalline basement terrains.
Oi Mangoua Jules Mangoua, Parfait Abé Sombo, Cyrille Thierry Adjé et al.· Journal of Applied Remote Se...· 0 citations
Previous works in southern Cameroon have highlighted prominent geological structures, including faults sub parallel to the Central Cameroon Shear Zone and the Sanaga Shear zone, exposed within the Central African Fold Belt along the northern margin of the Congo Craton. However, the relationships between these structures and the regional lithology require updating. Aeromagnetic data from the Akonolinga-Nguinda study area were processed using Oasis Montaj (v.8.4) software. Interpretation of the Reduced-To-Equator (RTE) magnetic anomaly field revealed multiple magnetic targets characterized by both positive and negative intensities. The RTE map provides a robust lithostructural framework, allowing for the correlation of structural faults with regional rock units. Derivative filter grids (horizontal gradient, vertical gradient, analytic signal, and tilt derivative) display an undulatory pattern, suggesting that the study area has undergone complex tectonic deformation, as corroborated by the mapped lineaments and intrusions. Consequently, the resulting structural map reveals a complex network of linear features predominantly oriented NE–SW, N–S, E–W and ENE–WSW. The 2.75D modeling along two NW–SE profiles drawn on the RTE grid indicates a crystalline basement composed of schists, quartzites, micaschists, gneisses and granulites intruded by pegmatite and quartz veins. Combined, these geophysical and structural results demonstrate that the study area has experienced intense, polyphase tectonic activity. The derivative filters highlighted the geologic contours/contacts and the general trend of structures. The maxima and multiscale maps helped to draw the structural map which showed lineaments whose main directions are NE-SW, ENE-WSW with variable dip. The 2.75D model inferred a subsurface down to 4 km depth with a lithology including sediment, schist, micaschists, gneiss and granulites; some intruded by pegmatite and quartz veins during tectonic movements. Beside intrusions, several tectonic discontinuities such as contacts/faults, factures and folds. The derivative filters highlighted the geologic contours/contacts and the general trend of structures. The maxima and multiscale maps helped to draw the structural map which showed lineaments whose main directions are NE-SW, ENE-WSW with variable dip. The 2.75D model inferred a subsurface down to 4 km depth with a lithology including sediment, schist, micaschists, gneiss and granulites; some intruded by pegmatite and quartz veins during tectonic movements. Beside intrusions, several tectonic discontinuities such as contacts/faults, factures and folds.
Yandjimaing Justine, Ngoumou Jean Paul, Teikeu Assatse William et al.· Discover Geoscience· 0 citations
The Okemesi Fold Belt, located within the southwestern Nigerian Basement Complex, is a structurally complex Pan-African terrain with documented occurrences of gold and base-metal mineralization. However, systematic evaluation of its structural and lithological controls remains limited. This study applies an integrated geological, petrographic, geophysical, radiometric, and geochemical approach to delineate structurally controlled mineralized zones and develop a mineral systems framework. Airborne aeromagnetic and radiometric datasets from the 2009 Fugro survey were processed using reduction to the equator, regional–residual separation, analytical signal enhancement, lineament extraction, and Euler deconvolution to map lithological boundaries, faults, and shear zones. Radiometric data for K, Th, and U were analyzed to identify hydrothermal alteration and lithological variations. These datasets were integrated with 1:25,000-scale geological mapping, petrographic analysis of representative lithologies, and multi-element geochemical analyses of thirty-six rock samples, including migmatites, banded gneisses, schists, quartzites, pegmatites, and charnockites. Multivariate statistical analyses highlighted significant elemental associations and anomalous zones. Results indicate that mineralization is structurally controlled, with shear zones, faults, and lithological contacts acting as primary fluid conduits. Geophysical anomalies coincide with hydrothermal alteration zones, felsic intrusions, and pegmatitic bodies, while petrographic evidence confirms deformation-enhanced recrystallization and sulfide mineralization. This integrated study provides a robust exploration model for structurally controlled, basement-hosted mineral systems and defines priority targets for follow-up investigations in southwestern Nigeria and analogous Pan-African terranes.
Ayodele Samuel Olusiji, Olususi Joseph Ige, Adebisi Matthew Iwabi· International journal of re...· 0 citations
This study investigates the geology, petrography, geochemistry, structural characteristics, and
economic mineralization potential of the crystalline basement rocks of Tillie and environs, Toro
Local Government Area, Bauchi State, Northeastern Nigeria. The study area forms part of the
Nigerian Basement Complex within the Pan-African Mobile Belt that reflect multiple tectono
metamorphic events related to the Pan-African orogeny. Field mapping, petrographic studies,
structural analysis, and geochemical investigations were integrated to characterize the
lithological units and evaluate their petrogenesis and mineralization potential. Geological
mapping involved reconnaissance surveys, traverse mapping, outcrop description, structural
measurements, GPS logging, and systematic sample collection. Thirty-seven representative rock
samples and stream sediment samples were collected from various locations across the study area
where 22 were analyzed. Structural data including foliations, fractures, joints, veins, and
lineaments were measured using a compass clinometer to determine the tectonic framework which
conformed to the NW- SE trend. Petrographic analysis was carried out using thin section
microscopy under plane-polarized and cross-polarized light. The petrographic results revealed
that the dominant lithologies include Banded orthogneiss, stromatic migmatites, alkali feldspar
granites, syenogranites and associated pegmatite and trachyte. Mineral assemblages identified
include quartz, plagioclase, K-feldspar, biotite, muscovite, garnet, orthopyroxene, mymerkite, and
opaque minerals. Geochemical analyses using Energy Dispersive X-Ray Fluorescence (EDXRF)
revealed compositional variations among the rock units and provided insight into their
petrogenesis. The rocks generally display felsic compositions with enrichment in silica, alkalis,
and light rare earth elements, consistent with crustal-derived melts, calc-alkaline, metaluminous
to slightly peralkaline affinities. Geochemical signatures suggest that the granitic and migmatitic
rocks were generated largely through partial melting and reworking of pre-existing continental
crust during the Pan-African tectono-thermal event. Trace element distributions and rare earth
element concentration indicate possible concentration for rare earth element-bearing accessory
minerals, zircon concentration and highly anomalous concentration of Antimony (21.6 wt.%).
P. Lila· International Journal of Agr...· 0 citations
This study aimed to establish the rich mineral potential of Southern Kebbi State's Neoproterozoic terrain and to highlight radiation hazards associated with uncontrolled mining activities in mineralised areas. Magneto-radiometric correlation analyses were used to delineate mineralised structural frameworks. The derivative filters, rose diagram, and Centre for Exploration Targeting (CET) analyses revealed near-surface structural networks trending mainly NE–SW. Analytic signal and 3D Euler deconvolution analyses helped classify the mineralised structures as shallow- or deep-seated. The estimated depth to mineralised structures ranges from 85.00 to 1282.30 m, with densely structured regions of interest hosting shallow structures within 85.00–203.30 m. The high occurrence of radioelements resulted in elevated activity concentrations, peaking at (1095.50 Bq/kg, 128.30 Bq/kg, and 88.75 Bq/kg), compared to lower crustal averages of (420.0 Bq/kg, 45.0 Bq/kg, and 33.0 Bq/kg) for AK, ATh, and AU, respectively. The annual dose rate ranged from 28.73 to 150.73 nGyh−1, surpassing the tolerable rate of 60.0 nGyh−1. AEDEin and AEDEout were estimated at 0.41– 0.73 mSvy−1 and 0.035–0.185 mSvy−1 respectively, against lower thresholds of 0.41 and 0.07 mSvy−1. Gamma, alpha, and radiological hazard indices remained within the safety limit of 1.0; however, reproductive health (AGDE) and cancer (ELCR) indicators, measured as 198.25–1042.16 μSvy−1 and (0.49–2.58) × 10−3, exceeded limits of 300 μSvy−1 and 0.29 × 10−3, respectively. Locations of mineral interest with high radiological parameters include Shanga, Beri, Bajida, Dafore, Rijau, Mazama, Agwara, Yelwa, Bin-Yauri, Maburo, Gulbin-Bako, Tungan-Numa, Makawa, Anaba, and Zoma. While the high radiological parameter values suggest significant potential health risks, expanding this study to include an assessment of the local population's health status was beyond the scope of the current research.
Suleiman Taufiq, Taiwo Adewumi, Nouhou Ibrahim et al.· Discover Geoscience· 0 citations
