ST
Chargé de Cours
Activité scientifique
Profil chercheur
Enseignant-chercheur à l’Université de Yaoundé I. Grade : Chargé de Cours.
Publications scientifiques
Ferdinand Deffo, Mbida Yem, Joseph Quentin Yene Atangana, Serge Parfait Koah, Yannick Saturnin Evina Aboula, Mahamed Moustapha Ndam Njikam
Heliyon
[This retracts the article DOI: 10.1016/j.heliyon.2024.e26319.].
Boris Secke Bekonga Gouott, Yakup Niyazi, Ovie Emmanuel Eruteya, Mbida Yem, Joseph Quentin Yene Atangana, Samuel Etame Makoube et 1 autre(s)
Submarine fans are deposits of sediments of continental origin in the deep sea, and are generally characterized by a complex depositional architecture, due to the multiple triggering mechanisms of deep-water sediment gravity flows.Consequently, this poses great challenges to deep-water petroleum exploration and development.We investigate the geomorphologic evolution and architecture of Campanian, deeply buried, submarine fans in the Kribi-Campo sub-basin, offshore Cameroon.Using a 3D seismic reflection data set and logs from two wells, we mapped horizons to produce seven strata slices including the fan base, fan top and five internal strata.In crosssection, the fan is characterized by high amplitude seismic facies exhibiting an aggradational pattern with parallel and continuous reflectors.The stacked fan-shaped morphology is up to 500 m thick, extends over an area of 600 km 2 and is oriented NE-SW, near the Kribi High.Analysis of the fan architecture reveals the presence of well-defined internal structures such as crevasse splay, a sinuous distributary channel and an elongated depositional lobe.The lobe whose beds are made up of sand, silt and mud.A detailed examination of the characteristics of the stratal slices has enabled us to propose a chronology of the Campanian submarine fan showing three phases of progression from its creation, and its growth to its abandonment.The detailed structure of this lobe has a finger-like morphology and is generally oriented at 90 o to the channel that delivered the sediment to the lobe.The finger-like features are interpreted as thick massive sands, formed as a result of gravity sedimentary flows which branched off the main flow eroding into pelagic clay substrate.It is important to note that the geomorphological evolution and architecture of the submarine fan were influenced by variations in sea level during the late Cretaceous and the underlying tectonics marked by the Kribi high.The 3D seismic geomorphological analysis of the submarine fan, as presented in this study, is essential to better understand their geometries, facies distribution, stacking patterns and depositional architecture to improve reservoir predictions.
Boris Secke Bekonga Gouott, Ovie Emmanuel Eruteya, Yakufu Niyazi, Mbida Yem, Joseph Quentin Yene Atangana, Pierre Eric Nkoa Nkoa et 1 autre(s)
Marine and Petroleum Geology
Ferdinand Deffo, Mbida Yem, Joseph Quentin Yene Atangana, Serge Parfait Koah, Yannick Saturnin Evina Aboula, Mohamed Moustapha Ndam Njikam
Heliyon
Finding drinking water in a Precambrian (Pan-African) basement context is a major concern for many Central African countries. For example, most groundwater is in fissured or fractured basement aquifers. To enhance the success rate of boreholes, this study aims to identify the features and the geographic reach of the lineament directions likely to drain groundwater. The research area has a size of 23 045 km 2 , is 120 km from Yaoundé, Cameroon, and is located there. The methodological approach integrates current borehole and outcrop data with spatial data (Landsat-8 OLI/SRTM and gravity). The main NE-SW (N20–70°E), E-W (N80–100°E), and secondary N–S (N0–20°E) and NW-SE (N120–140°E) fracture directions display on the generated structural lineament map. The Pan-African orogeny is linked to the E-W direction, and the Sanaga Fault is related to the NE-SW direction. The other directions (N–S and NW-SE) correspond to the post-collisional decompression phase. This study locates medium-flow boreholes on or near the NE-SW, E-W, and NW-SE trending fractures, hence enhancing the knowledge of fissured and fractured basement aquifers in the Central region of Cameroon. The corresponding water flow rates range from 1 to 3 m 3 /h as well. The extensive exploration of fractured bedrock aquifers can benefit from these findings.
Mohamed Moustapha Ndam Njikam, Mbida Yem, A. Ribodetti, Ahmed Mohamed, Aboubacar Soumah, Moaboulou Prosper et 2 autre(s)
Frontiers in Earth Science
The present work used the electrical resistivity approach to conduct a three-dimensional modeling and initial volume estimation of the limestone layer in the Mintom region located in southern Cameroon. In order to achieve the objectives of the study, a total of 21 electrical soundings spaced 250 m were first collected in the field using the Schlumberger array. These soundings were conducted along three profiles oriented in an east–west direction, spaced 500 m. Additionally, a geological survey was conducted to identify and emphasize the presence of limestone formations within the designated study region. The interpretation of the sounding data was conducted based on the analysis of the sounding curves. The interpretation outcomes, specifically resistivity and thickness, were compared with the geological field data, resulting in the development of lithostratigraphic logs for each sounding. The geological sections were constructed using the logs of the designated profile. The lithological logs were utilized to establish a lithological interface model and calculate the volume of the limestone layer at 260 ± 13 × 10 6 m 3 , utilizing the inverse distance method built into RockWorks software. A resistivity value is assigned to each geological layer in a sounding curve, allowing for the development of a resistivity variation model specific to the limestone layer. The proposed model facilitates the categorization of limestone layers based on their resistivity variations, thus serving as a fundamental reference for prospective exploratory activities within the designated study region. Our integrated approach provides a replicable model for a better understanding of the limestone reserve and effective management of this valuable resource.
Renaud Menanga Tokouet, Joseph Quentin Yene Atangana, Mbida Yem, Emile Ekomane, Ferdinand Deffo, Florent Daniel Akono et 1 autre(s)
Studia Geophysica et Geodaetica
Hendratta Ali, Manika Prasad, Ahmed Ismail, Njilah Isaac Konfor, Yene Atangana Joseph-Quentin, Oluseun Adetola Sanuade et 3 autre(s)
Second International Meeting for Applied Geoscience & Energy
Globally, potable water shortage is severe. This shortage is increasingly exacerbated by the global climate crisis. Access to clean water remains one of the most important and vital pursuits that are necessary to achieve the United Nations sustainable development goals. Our paper will report results of our project that aims to contribute to advancing access to portable and available groundwater, trapped in fractured rocks, to a populated rural community. Through technical collaboration, the project team will mentor student and work with local scientists and stake holders using geoscience tools.
Nkoungou Gregory José, Loudi Yap, Yené Atangana Joseph Quentin, Mbida Yem, Nguijol Cyril Gabriel
Arabian Journal of Geosciences
Mike-Franck Mienlam Essi, Joseph Quentin Yene Atangana, Mbida Yem, P. Nguema, A. Ribodetti, Tedy Landry Tonye
HAL (Le Centre pour la Communication Scientifique Directe)
International audience
Hendratta Ali, Njilah Isaac Konfor, Joseph Quentin Yene Atangana, Alice Magha, Arkhat Kalbekov, Mathias Pohl et 4 autre(s)
The availability of portable water continues to be a major challenge in many parts of the world and the rural community of Nkoteng in Cameroon is no exception. In this community, challenges associated with access to safe drinking water are mostly due to problems of surface water contamination and pollution. Consequently, deep groundwater within the fractured basement rock should be a relatively cleaner and safer option for domestic use. The Society of Exploration Geophysicists – Geoscientists Without Borders program funded this project with the goal to use geoscience tools to investigate fault–zone aquifers, the water quality of existing water sources in the project community, and to mentor students in applied geoscience field experiences. Presentation Date: Monday, October 12, 2020 Session Start Time: 1:50 PM Presentation Time: 3:55 PM Location: 360C Presentation Type: Oral
Mbida Yem, Joseph Quentin Yene Atangana, Serge Parfait Koah Na Lebogo, Mike Franck Mienlam Essi
Journal of the Cameroon academy of sciences
The Paleocene aquifer of the Douala-Massoumbou sub basin is a rhythmic sequence of sand and shale deposits. Resistivity pseudosections and profiles of half-distance between current electrodes of 350m were acquired at 20 different sites of the Douala-Massoumbou subbasin. These data coupled with mud and gamma-ray logging of deep groundwater boreholes led to the identification of two major sand sequences through the Paleaocene-Eocene stratigraphic section. The upper sequence associated with Ypresian 30-50 m thick unconformity made up with semi-conductive records, is punctuated by lenses of substantially water bearing sand (WBS). While the lower sequence locally associated with H2S and iron pollution plumes, displays high conductive records. In such sequences, the distribution of sand and clay deposits settled by channel incision appears fundamental in predicting reservoir geometry and the hydrological potential of the Paleocene WBS.Keywords: Sag basin, electrical tomography, Paleocene formation, water-bearing sand.L’aquifère du Paléocène du sous-bassin de Douala-Massoumbou est une séquence rythmique de dépôts de sable et d’argile. Des sondages géoélectriques tripole (OA=350m) et des tomographies de résistivitéont été acquis sur 20 sites différents de la zone de faible enfouissement de cet aquifère. Ces données, couplées aux résultats des diagraphies gamma-ray et des déblais des forages hydrogéologiques profonds, ont permis d’identifier deux séquences de sable hydrostratigraphique au sein de l’aquifère paléocèneéocène. La séquence supérieure semi-conductrice correspond à dépôts de sable aquifère sain, épaisse de 30 à 50 m et associés à la discordance ypresienne. La séquence inférieure très conductrice, correspond à des chenaux de sable aquifère pollué par le sulfure d’hydrogène (H2S) et le fer. La mise en corrélation de l’ensemble des résultats obtenus a permis de constater que la prise en compte du développement spatial des chemins hydrologiques fossiles est un critère fondamental pour la prédire la distribution et l’exploitation des niveaux de sable aquifère sain du Paléocène du sous-bassin de Douala-Massoumbou.Mots clés: Bassin de fossé d’éffondrement, tomographie électrique, Formation paléocène, Sag basin, electrical tomography, Paleocene formation, niveaux de sable aquifère sain.
Mike-Franck Mienlam Essi, Mbida Yem, Joseph Quentin Yene Atangana
International Geophysical Conference, Beijing, China, 24-27 April 2018
In order to highlight the sedimentary succession and the tectonic style of the deposits of the deep marine domain of the Kribi-Campo sub-basin, a study based on the reinterpretation of a CameroonSpan seismic line was carried out. The results obtained are as follows: from the acoustic point of view, the amplitude variations of the seismic reflections make it possible to distinguish the limit between the basement and sedimentation around 10 km deep. The pre-Barremian sedimentary prism, which is about 5 km thick at the basin scale, ends in a bevel on the submarine horst of Kribi-Campo. The internal configuration of this sedimentary stack distinguishes two surfaces of seismic discontinuities (S1 and S2). The geological meaning of these boundaries, respectively, represents a downlap surface and an erosion surface. These discontinuities define three seismic sequences (SE1, SE2 and SE3). They are all sub phases deposits belonging to a first order sedimentary cycle. The correlation between seismic and global eustatic chart, shows that these deposits are pre-Cretaceous; structurally, this sedimentary cover is intersected on the East side (Kribi high) by synthetic normal faults and on the west side (Yassoukou under marine high), by antithetic inverse faults. The observation of normal and inverse structures in the same sub-basin, suggest an inversion of the initial tectonic. The synthesis of all these data suggests an older sedimentation in the basin in comparison with sedimentation known on onshore.
Zoo Zame P, Mbida Yem, Yene Atangana JQ, E Ekomane
Journal of Geology & Geophysics
The upper Dja series consists of carbonates and shales deposits that date 580 ± 150 Ma. Petrography and mineral chemistry studies helped to differentiate this series into many sequences including massive limestone layers with calcite (CaO3) contents of about 30 to 42%. In order to determine the subsurface distribution of these sequences, a geophysical prospection campaign was carried out in which a total of 24 vertical resistivity soundings were recorded over a surface area of 9 km2. The processing and interpretation of data using the IX1D and OpendTect modeling tools permitted the distinction of two massive limestone layers in the upper Dja series. The first layer of about 10 to 35 m thick and outcrop in few places is characterized by resistivity ranging between 1110 and 2377 Ωm, while the second layer located beyond 50 m deep is separated by a very conductive clay stone layer with a capped thickness of 15 to 35 m. 3D modeling of the top and base of these formations indicates that, the whole Upper Dja series of about 190 m thick presents folded structure. These results can constitute a useful base of information in regards to a large scale economic study of the Upper Dja limestone series.
Dieudonné Bisso, Mbida Yem, Serge Parfait Koah Na Lebogo, Joseph Mvondo Ondoa, Carine Tsoungui
Le bassin de Garoua est une structure d’allongement N90 a N115. Il est constitue de 1000 a 4000 m d’epaisseur de sediments donc l’âge varie de l’Aptien au Maastrichtien. Ces depots sedimentaires sont traverses par des venues volcaniques (basaltes ou trachytes) d’âge Priabonien. Dans le cadre de cette etude, l’analyse morphostructurale a partir des MNT de 30 m de resolution spatiale montre que les failles coulissantes N135°E a N250°E, ont influencees l’evolution recente du bassin de Garoua. L’examen du developpement global de ce systeme met evidence deux phases de deformation post sedimentaire. A savoir une phase de tectonique des blocs (decrochement) fin cretace et une phase d’inversion (transpression) Mio-pliocene. Le jeu inverse des failles N90°E a N115°E initialement normales aurait provoque durant cette derniere phase, la surrection du bassin, avec pour consequence l’erosion des depots tertiaires.
Mbida Yem, Yené Atangana Joseph Quentin, Ponce Nguema
ASEG Extended Abstracts
From the Campo onshore to the Malabo-Victoria volcanic line, the Cameroon Atlantic Basin comprises two main segments: the Ekite-Kordofan transform-fault basin and the Wouri-Yassem deep-graben structure separated by the Yassoukou-Tissongo-Ossa reverse fault. The major morphologic features of the Ekite-Kordofan transform-fault basin are Kribi-Campo half-graben and the Elombo-Nkoundou internal shear zone.Detailed analyses of long offset pre-stack depth migrated seismic sections enabled mapping of buried fan-delta at approximately 20 km southwest of the Kribi-La Lobe river mouth. The fan is up to 25 km wide, 4km thick and is morphologically expressed in the form of bank clinoform sequences. By correlation of seismic records with borehole data from adjacent areas, it appears that the fan is divided in two morphologic divisions (upper and lower fan). The lower fan uniformly returns transparent weak seismic record, with intermittent internal reflections. In contrast, the upper fan is characterized by acoustically high amplitude clinoform reflections. Within this package, listric growth faults are common, and the fan tends to mound up were salt domes are present beneath Bedoulian-Aptian boundary. These results opened up Aptian-Albian fan-delta play of the Cameroon Atlantic Basin and help to introduce new hydrocarbon concepts and exploration opportunities.
Philippe Njandjock Nouck, Mbida Yem Atangana, Leonel Amougou, Pius Lissom, Mbida Yem
Journal of Emerging Trends in Engineering and Applied Sciences
This geophysical study was carried out in the city of Eseka, the head quarter of Nyong and Kelle Division, Center Region of Cameroon. It had as aims to prospect aquifers and to propose models of geophysical structures of the underground basement in the city. To this effect, the geophysical method of electrical resistivity was chosen, due to the local geologic context, and its easy application. With the aid of a resistivitimeter of mark TERRAMETER ABEM SAS 300, twenty (20) electrical soundings were effectuated in different points in the city. The treatment of data was done through several interpretation software, such as Geo-Elect. Mod and surfer8.0. Qualitative and quantitative interpretations, coupled with field and laboratory observations, permitted: the characterization of the lateritic crust constituted of the model of the terrain, into four and five layers of distinct terrain by their resistivity and thicknesses; the definition of the average depth of the upper aquifer from about three (03) meter in the loose clayey level, and the lower aquifer at about thirty (30) meter in the weathering and fractured gneiss level; the localization of the zone of conduction and resistant anomaly, at chosen depths in the study area. These results are important in future modeling process of the aquifers in this area.
Mike-Franck Mienlam Essi, Eun Young Lee, Mbida Yem, Jean Marcel Abaté Essi, Joseph Quentin Yene Atangana
Geosciences
The Kribi-Campo sub-basin, located in the Gulf of Guinea, constitutes the southeastern segment of the Cameroon Atlantic Margin. Drilling in the Aptian salt unit revealed a sparse hydrocarbon presence, contrasting with modest finds in its counterparts like the Ezanga Salt in Gabon and the Rio Muni Salt in Equatorial Guinea. This discrepancy prompted a reassessment of the depositional context and hydrocarbon potential of the Mundeck salt unit. By integrating 2D seismic reflection and borehole data analysis, this study established the structural and stratigraphic framework of the area, emphasizing the salt unit’s significance. Borehole data indicate a localized salt unit offshore Kribi, with seismic reflection data revealing distinct forms of diapir and pillow. This salt unit displays a substantial lateral extent with thicknesses ranging from 4000 m to 6000 m. The depositional context is linked to the following two major geological events: a significant sea-level drop due to margin uplift during the Aptian and thermodynamic processes driven by transfer faults related to mid-oceanic ridge formation. These events were crucial in forming and evolving the Mundeck Salt. Regarding hydrocarbon prospects, this study identifies the unit as being associated with potential petroleum plays, supported by direct hydrocarbon indicators and fault-related structures. The findings suggest that untapped hydrocarbon resources may still exist, underscoring the need for further exploration and analysis.
Jean Marc Medza Ekodo, Mbida Yem, Joseph Quentin Yene Atangana, Serge Parfait Koah, Georges Emmanuel Ekodeck
Journal of Seismology
Mohamed Moustapha Ndam Njikam, Mbida Yem, Arsène Meying, A. Ribodetti, Gabriel Messi, Chiewo Ceukou Téthys-Authie et 1 autre(s)
Geophysical Prospecting
Abstract The present study attempts to combine direct current and induced polarization methods for 3D geological modelling and preliminary volume estimation of gold mineralization targets in the Simi locality, Adamawa, Cameroon. To begin, resistivity and chargeability data were collected along seven profiles oriented in N150E using the electrical tomography technique. A geological investigation was also carried out and allowed in addition to the geological formations to highlight the existence of gold mineralization in the study area. The interpretation of the inversion results was done by taking into consideration the geological field data and the existing resistivity charts. The 3D distribution of the interpreted sections allowed us to make a horizontal correlation between the different sections and to elaborate the 3D geological model of the study area by using the deterministic inverse distance method. The estimated model indicates a volume of 621,130.625 m 3 of the possible gold complex. The gold complex was then divided into two mineralization domains based on chargeability ranges (mV/V): A first domain is associated with a major mineralization zone (39–60 mV/V) with a volume of 10,842 m 3 , and a second domain is associated with secondary mineralization zone (18–39 mV/V) with a volume of 610,288 m 3 . This model allows to compartmentalize the gold complex and can be used as a base model for the gold investigation in the study area.
Jean Lucien, Mbida Yem, Armel Zacharie Ekoa Bessa, Thomas Tamo Tatiétsé, Dieudonné Bisso, Abdelaziz Mridekh et 2 autre(s)
Arabian Journal of Geosciences
Abstract The empirical GIN (grouting intensity number) method is one of the most popular methods for structural stabilization and is increasingly used in many projects. The concept of this method is to limit the combination of pressure and volume injected to a specific grouting intensity number in order to control the energy induced in the rock fractures and to avoid heaving. In order to ensure the water tightness of the foundation of the Memve’ele hydroelectric dam, the treatment by the GIN method was implemented. The protocol implemented consisted to carry out a veil of injection drilling, consolidation, and control of effective treatment on each geotechnical hazard zone. Thus, 1240 injection boreholes were opened over a total length of 1600 m, i.e.: 613 pre-treatment boreholes and 627 consolidation boreholes. The results of the monitoring tests show that the 0.7 cement grouting treatment contributed to a reduction in crack permeability to less than 5 Lu (Lugeon units), a reduction of over 94%. This confinement of the rock was confirmed by geophysical imagery whose signature at the fractured interval varied after treatment. Geophysical and geohydrological characterization through permeability testing and electrical tomography revealed the existence of highly permeable discontinuity zones (over 90 Lu) below the bedrock surface, up to 15 m wide. Notwithstanding the volume of drilling carried out, the results obtained support the use of the GIN method in the stabilization of foundations of structures in the granite-gneissic basement zone.
Salimatou Diallo, Mohamed Moustapha Ndam Njikam, Mbida Yem, Joseph Quentin Yene Atangana, A. Ribodetti, Abdou Raouf
Exploration Geophysics
This study combines the processing and interpretation of magnetic data with geological fieldwork. The purpose is to establish the geological map and rutile mineralization targets map of Minta area (Haute-Sanaga, Cameroon). To this, a strategic geological field survey was first conducted. It highlighted some geological structures, especially magnetite quartzites, which is considered as the potential sources of primary rutile mineralization. Several methods were applied to the magnetic data, including upward continuation (UC), vertical derivative (DZ), analytical signal (AS) and horizontal gradient magnitude (HGM). The regional-residual separation method based on the UC was used to develop the residual map which was very helpful to understand the distribution of magnetic anomalies related to rutile mineralization in this area. The structural model of the study area was established by combining the analysis of the AS and HGM maxima with the analysis of the topographic model. Since magnetic relief variation characterizes the lithological information changes according to the filtered map considered, a set of categorization processes based on the anomaly signals was applied to each of filtered maps according to the geological information sought. It is based on the interpretation of structural models, combined with previous works and the spatial distribution of geological data collected. This process produced a set of partial lithological models, which were then combined with the interpreted structural model to produce the geological map of the study area. This map also shows the spatial distribution of the various targets of potential rutile mineralization interpreted on the DZ model as rectilinear anomalies, with a signal range of 0.78–0.88 nT/m.
Mike-Franck Mienlam Essi, Joseph Quentin Yene Atangana, Mbida Yem, Serge Edouard Angoua Biouélé, Eun Young Lee
This work re-examines the salt unit through the Kribi-Campo sub-basin on the southeast part of the Cameroon Atlantic Margin. The results obtained from borehole data analysis show the occurrence of an evaporitic unit, localized in the Kribi area. The well to seismic-tie analysis reveals that this unit is observed beneath the Top Albian Unconformity and between the Flooding and Maximum Flooding Surfaces. Two characteristics of the salt dome and salt strips are described. Their depositional context seems to be related to a significant sea-level drop induced by a margin uplift during the Aptian. Concerning the petroleum implications, the target units constitute the good potential of stratigraphic traps in the study area, due to the observation of flatspot indicators.
Boris Secke Bekonga Gouott, Ovie Emmanuel Eruteya, Yakufu Niyazi, Mbida Yem, Joseph Quentin Yene Atangana, Adolphe Lorcin Maloh et 2 autre(s)
Submarine fans are deposits of coarse sediments of continental origin in the deep sea, and are generally characterized by a complex depositional architecture, due to the multiple triggering mechanisms of deep-water sediment gravity flows. Consequently, this poses great challenges to deep water petroleum exploration and development. We analyzed the geomorphologic evolution and architecture of Campanian, deeply buried, submarine fans in the Kribi-Campo sub-basin, offshore Cameroon. Using a 3D seismic reflection data set and logs from two wells, we mapped seven horizons, including the fan base, fan top and five internal horizons. In cross-section, the fan is characterized by a high amplitude seismic facies exhibiting an aggradational pattern with parallel and continuous reflectors. The stacked fan-shaped morphology is up to 340 ms TWT thick, extends over an area of 600 km2 and oriented NE-SW, near the Kribi High. The analysis of lobes and channels on each horizon provided a timelapse that captures the major geomorphologic transformations of the submarine fan from its initiation, growth, and abandonment.  The submarine fan is composed of depositional lobes whose beds consist of sand, silt and mud. The detailed structure of these lobes has a finger-like morphology and is generally oriented at high angles to the channel that delivered the sediment to the lobes. The finger-like features are interpreted as thick massive sands, formed as a result of sediment-gravity flows which branched off the main flow eroding into pelagic clay substrate. Two types of channel morphology were identified (straight and sinuous). Our results show that channel and sand-body architecture evolve in a predictive manner, primarily controlled by fan aggradation. The elongated shape and morphology of the submarine fan may arise from the interaction of the fault-related folds and Kribi High, with sandstone deposition within the intervening topographic lows, sourced from the east. The 3D seismic geomorphological analysis of the submarine fan, as presented in this study, is essential to better understand their geometries, facies distribution, stacking patterns and depositional architecture to improve reservoir predictions.
Elie Fosso Menkem, Mbida Yem, Constantin Ndongue, Paul Gustave Fowé Kwetche, Jeremy E. Martin, Benjamin Ngounou Ngatcha et 1 autre(s)
Geosystems and Geoenvironment
The Mayo-Oulo-Lere Basin, with an overall surface area of 122 km2 is located in northern Cameroon between the western extension of the Doba Basin and the eastern edge of the Benue Trough. This study maps the depth and spatial development of Bambalo sedimentary sequences in the Mayo Oulo-Lere Basin that were deposited during the Cretaceous. The depositional sequences present an exposure of crocodile fossils and plants evidenced by superficial alteration. The Bambalo Formation is described in terms of lithostratigraphy, vertical electrical sounding (VES) and electrical resistivity tomography (ERT) to provide a better understanding of stratigraphic evolution and setting conditions during sedimentation. Sedimentary deposits in the Mayo Oulo-Lere Basin are mainly fluvio-lacustrine deposits consisting of alternating claystone, siltstone and limestone. The lithostratigraphic log of Bambalo for the subsurface geology up to 25 m presents three main depositional sequences named S1, S2 and S3. S1 presents ripples marks and desiccation cracks that are directly observed on the surface outcrop. The separation between S1-S2 and S2-S3 is marked by unconformity surfaces. The sedimentary sequences are dominated by retrogradational depositional trends that describe short sequences of fining-upwards successions. The ERT image results obtained from geophysical analysis using Res2Dinv display local features associated with folding in the aforementioned sedimentary thickness of approximately 30 m. Additionally, the VES analyses using ipi2win software show that the upper 78 m part of the Bambalo formations is composed of four layers (L1, L2, L3 and L4) distinct by resistivity. L4 Layer correlated with the top of lithostratigraphic log S3, while L3 is a semiresistive set of 78 Ω·m layering S1 and S2 lithostratigraphy sequences. Layer L2 corresponds to a conductive set with resistivity of approximately 27 Ω·m above the lower layer L1, a resistive sequence with resistivity greater than 1000 Ω·m. The combination between the major rifting faults (N70°, N110° and N130°E), syntectonic sedimentation and Barremian-Aptian age attributed to sediments of Bambalo demonstrate clearly that the sediments were deposited during or few time after the rifting phases. The sediments are resulting from a rapid filling of the basin characterised with retrogradational sequences that are controlled by the evolution between accommodation space created after each tectonic phase and the base water level rise within the basin. The rapid elevation of water and sedimentation might be one of the reasons of the massive death of crocodilians. The results of this study demonstrate that the combination of ERT and lithostratigraphic analysis is a powerful tool for a better understanding of the Bambalo sedimentary process and basin evolution. The lateral and vertical evolution of the layers being proven, a future deep excavation will certainly make it possible to bring to light new types of fossils from these deposits and in the neighbouring basins.
Boris Secke Bekonga Gouott, Mbida Yem, Joseph Quentin Yene Atangana, Pierre Eric Nkoa Nkoa, Serge Edouard Angoua Biouélé, Yakufu Niyazi et 1 autre(s)
Marine and Petroleum Geology
Boris Secke Bekonga Gouott, Mbida Yem, Joseph Quentin Yene Atangana, Eric Pierre NKOA NKOA, Serge Edouard Angoua Biouélé, Yakup Niyazi et 1 autre(s)
In this study, a seismic reflection dataset and well-log data were integrated to investigate the geometry and internal configuration of a turbidite channel system within the Late Cretaceous interval of the deep-water Kribi-Campo sub-basin, offshore Cameroon. This interval is characterized by a well-developed submarine channel system consisting of an early and a late-stage channel. Morphologically, the submarine channel system has a northeast-southwest trend and is U-shaped in cross-section with a length of 56 km within the study area. The early-stage channel has a relatively straight morphology and varies in width and depth from 3 to 5 km and 89 to 197 m, respectively. However, the late stage of the channel is characterized by a narrower (1 to 3 km) and shallower (41 to 103 m) incision, with sinuous morphology carved into the early channel infill. The changing interaction of differential tectonic subsidence, relative sea level, source sediment supply and slope gradient change are considered to be the major control on the geometry and internal characteristics of the submarine channel system. Sag subsidence during the Campanian led to basin deepening and the widespread development of basinal sediments as submarine fans and promotion of submarine channel system development. The filling of the channel system occurred during a long-term Maastrichtian relative sea level rise, punctuated by falls in relative sea level. Sand appears to have been fed to the channel system by the palaeo-Sanaga and palaeo-Nyong Rivers, with sand rich aprons developed were these rivers debouched into the study area. The early stage of the submarine channel is dominated by coarse-grained sediments in the southwest and fine-grained sediments in the northeast, while the late-stage channel is mainly filled with fine-grained sediments. The presence of coarse-grained sediments occur within the submarine channel axis downstream represents a potential for hydrocarbon reservoirs with enhanced petrophysical qualities due to a low depositional gradient. The geomorphological analysis of this ancient submarine channel system along the western African margin, as presented in this study, has broad implications in the understanding of the distribution of deep-water sediments with potential for hydrocarbon exploration in the region.
M.E. Mike-Franck, Mbida Yem, Joseph Quentin Yene Atangana, P. Nguema, A. Ribodetti
Summary The study area is located at the southern part of the Cameroon Atlantic Margin (CAM) in the Gulf of Guinea. This work analyses 20 wells and 02 CameroonSpan seismic lines to re-examine the stratigraphical nature of the Top Albian surface of the CAM for a better understanding of the Basin evolution. The wells analysis results show that, from onshore to deep marine, this surface has an erosive shape. The seismic analysis reveals that this surface has two characters: erosive from the continental shelf to continental slope and concordant in the deep basin. This observation indicates that the Top Albian surface corresponds to an unconformity (u/c) on shallow waters with its correlative conformity (cc) in deep domain. The well-to-seismic tie reveals that in shallow waters, the Top Albian u/c erodes Aptian-Albian deposits. These sediments mainly consist of sandstones, shales and evaporitic unit. The occurrence of dark shales before late Albian epoch, suggests that the study area was already transgressed by marine sediments at this time. Hence, the Top Albian surface resulted probably from a sea-level drop, mainly caused by the margin uplift. The 3D modeling carried out provides a better resolution of its regional extension in the South Cameroon Atlantic Margin.
Mike-Franck Mienlam Essi, Joseph Quentin Yene Atangana, Jean Marcel Abaté Essi, Mbida Yem, Serge Edouard Angoua Biouélé, Ponce Nguema et 1 autre(s)
Marine and Petroleum Geology
Profil chercheur
Publications scientifiques
2 publications
3 publications
7 publications
5 publications
4 publications
1 publication
1 publication
1 publication
1 publication
1 publication
1 publication
1 publication
Collaborations
