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International Journal of Geosciences 2023年第8期14卷 733-766页

作者： moussa Fall Ibrahima Labou Papa moussa ndiaye Department of Geology Faculty of Science and Technology Cheikh Anta Diop University Dakar Senegal National Superior School of Mines and Geology Cheikh Anta Diop University Dakar Senegal

Detailed work on Quaternary volcanism has been carried out in the Mermoz and Fann sectors of western Senegal. In the Mermoz sector, the main emission zone is a collapsed crater located at the intersection of three major fractures: NE-SW, NW-SE and N-S. The lithological succession in this Mermoz sector comprises, from bottom to top: 1) a substratum with at its base Eocene limestones on which lie Quaternary sands surmounted by stratified tuffs;2) a vesicular ball dolerite which deforms the stratified tuffs;3) a dark early breccia;4) two generations of basanites: the first is vesicular, the second non-vesicular;5) a clear intermediate breccia and finally 6) a late breccia. The Fann sector contains several emission zones, most of which are currently located in the ocean. The lavas may have reached the coast through E-W and NE-SW faults. The lithological succession includes from bottom to top: 1) scoria-rich early volcanic breccias;2) a first generation of non-vesicular mesocrate dolerite (D1);3) a second generation of melanocrate vesicular dolerite (D2);4) basanites and finally 5) a late breccia. The geochemical characteristics of the lavas studied are compatible with a very enriched and very deep magmatic source of the garnet lherzolite type located in the lower mantle. The magma from this source would have risen in the form of mantle plumes through major NE-SW and E-W faults in a continental intraplate context.

关键词： Quaternary Volcanism Western Senegal Emission Zone Geochemistry Con-tinental Intraplate

Polycyclic Evolution of Paleoproterozoic Rocks in the Southwestern Part of the Mako Group(Eastern Senegal,West Africa)

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International Journal of Geosciences 2014年第7期5卷 739-748页

作者： Papa moussa ndiaye Edmond Dioh Famara Diatta Alassane Traore Makhoudia Fall Ousmane Balde Département de Géologie Universite Cheikh Anta DiopDakarSénégal Institut Fondamental d’Afrique Noire Universite Cheikh Anta DiopDakarSénégal Institut de Technologie Nucléaire Appliquée Universite Cheikh Anta DiopDakarSénégal

After an extensional stage giving rise to tholeiitic basalts and gabbros, the south western part of Kédougou Kéniéba Inlier (KKI) was affected by three phases of compressionnal deformation. The first phase (D1) was related to NE-SW stress that led to northeastward thrusting. Early granitoids would be implemented during this tectonic event. The second phase (D2) was due to East-West compressional stress that created combined strike sleep faults: NNW-SSE and NNE-SSW respectively sinistral and dextral. During this phase, some volcanic rocks and gabbros were mylonitized, hydrothermalized and transformed into quartzites. These quartzites were considered as sedimentary rocks in previous studies. Granitic plutons and andesites took place during this tectonic phase. D3 deformation occurred towards the end of the Eburnean orogeny. It would be held in two episodes. In the first episode, WNW-ESE stresses created conjugate shears: sinistral NNW-SSE and dextral NE-SW. In the second episode, stresses moved toward the NE-SW direction and made the resulting brittle structures arranged in NS dextral corridors.

关键词： Paleoproterozoic Eastern Senegal Volcanic-Rocks Polycyclic Deformation Silicification

Lithostructural Control of the Gold Mineralization of the Douta Permit of African Star Resources (Kédougou-Kéniéba Inlier, Southeastern Senegal)

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International Journal of Geosciences 2024年第4期15卷 303-333页

作者： Masse Ndour Papa moussa ndiaye Koffi Félix Ekra Alain Ndong Malick Faye Pierre Ndour African Star Resources Yoff Dakar S&#233n&#233gal Dé partement de G&#233ologie Universit&#233 Cheikh Anta Diop Dakar S&#233n&#233gal

The Douta permit of African Star Resources/Thor Explorations, located in the southeast of Senegal, in the Kédougou-Kéniéba Inlier (western part of the West African Craton), is dominated to the East by metasedimentary formations such as greywackes, shales, graphitic shales, quartzites, cherts, claystones and breccias characteristic of the Dialé-Daléma basin. To the West, the mafic formations of the Mako volcanic belt are the most common. Metasedimentary rocks are associated with metavolcanosedimentary terms found at the contact zones between the two (2) Birimian groups. These different geological formations are cut by mafic dolerite and gabbro sills and/or dykes, as well as quartz and microgranite veins. The Douta gold project is crossed from North to South by the MTZ (Main Transcurrent Zone), generally oriented NE-SW and becoming N-S towards the North. The permit is characterized by several shear corridors. The rocks are affected by brittle, brittle-ductile to ductile deformations. The gold mineralization is hosted by a NE-trending shear corridor called the Makosa corridor (Makosa shear zone), therefore sub-parallel to the MTZ. It has a subvertical dip (75˚ to 85˚ to the NW). It is associated with a hydrothermal phase characterized by quartz-sericite-epidote-fine, disseminated pyrite and arsenopyrite ± albite ± chlorite paragenesis. These minerals testify to the existence of a low degree of metamorphism (greenschist facies, epizonal domain) in the area. However, metamorphism reaches amphibolite facies in some places, particularly in the vicinity of intrusive bodies, with the presence of hornblende (amphiboles) and plagioclase. The gold mineralization is mainly hosted by two (2) metasedimentary lithological units: meta-greywackes and shales.

关键词： Douta Kédougou-Kéniéba Inlier Senegal Metasedimentary MTZ Control Gold Mineralization Makosa Corridor

Petrological and Structural Approach to Understanding the Mechanism of Formation and Development of Paleoproterozoic Calc-Alkaline Volcanic Rocks of West Africa’s Craton: An Example of the Mako and Foulde Groups (Kedougou Inlier in Western Senegal)

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International Journal of Geosciences 2015年第7期6卷 675-691页

作者： Adrien Gozo Mahamadane Diène Dinna Pathé Diallo Edmond Dioh Mamadou Gueye Papa moussa ndiaye Département de Géologie Université Cheikh Anta Diop Dakar Senegal Institut des Sciences de la Terre Université Cheikh Anta Diop Dakar Senegal Institut Fondamental d’Afrique Noire (IFAN) Université Cheikh Anta Diop Dakar Senegal

The calc-alkaline volcanic formations in the western part of the Kedougou-Kenieba inlier crop out in three complexes: the Foulde in the North and the areas of Mako and Baniomba in the South. These complexes which either combine with the tholeiites or cut across the sedimentary formations are composed of thin veins and massive lava flows. They have many petrographic similarities and show chemical characteristics that resemble those of island-arc rocks. At the tectonic level, the D1 deformation phase preceding the formation of the basins and the transpressive tectonics including an oblique convergence may account for the structural evolution of the Mako volcanic belt. Its occurrence in different basins may be evidenced by the composition of some lithophilic components like the Sr, Ba, U, Rb and the composition of clinopyroxenes enriched in TiO2, FeO, Na2O in the Foulde calc-alkaline volcanic rocks that developed in a sedimentary environment.

关键词： Volcanism Calc-Alkaline Kedougou-Kenieba Inlier Tectonic Stress Transpressive Tectonics

Study of Antenatal Care Completion Determinant Factors in Kedougou Health District (Senegal)

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Open Journal of Obstetrics and Gynecology 2020年第10期10卷 1449-1470页

作者： Babacar Biaye David Ngom moussa ndiaye Fode Danfakha Omar Gassama Abdoul Aziz Diouf Adama Faye Dembo Guirassi Alassane Diouf Jean Charles Moreau Aristide Le Dantec Teaching Hospital Dakar Senegal kedougou Health District Kedougou Senegal Public Health Department Cheikh Anta Diop University Dakar Senegal Reproductive Health Department/Health Ministry Dakar Senegal

Introduction: Maternal mortality is a public health problem of more concern to developing countries. As part of improving the maternofoetal prognosis during pregnancy and childbirth, it is essential to carry out regular follow-ups of pregnant women (FE) through antenatal consultations (ANC). In fact, the World Health Organization (WHO) recommends at least four ANC at regular intervals during pregnancy. In Senegal the completion rate varies greatly depending on the region. In the District of Kédougou it was 41% in 2017 (DHIS2). The national target was not achieved despite the interventions. Thus we studied the determinants of CPN completion in the health district of Kedougou in 2017. Method: The study is of a descriptive and analytical cross-sectional type and concerned a sample of 884 women who gave birth between October 2017 and September 2018. They were chosen by a sample whose distribution in the district was made according to the quota method while respecting the demographic weight of each area of responsibility of the District. Results: The results of our study showed that the average age of women was 24 years with an average number of pregnancies equal to 3. The ANC completion rate at 37% was lower than the administrative data rate which was 41%. The determinants with a statistically most significant link with the completion of ANC are respectively satisfaction with the care and quality of service, the level of information of women regarding PNC, marital status, affordability and distance from the location of t

关键词： Prenatal Consultation Completion Kédougou

Tele-Analytical Characterization of the Eburnean Tectonic Structures within the Birimian Formations of Mako Area, Eastern Senegal

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International Journal of Geosciences 2022年第1期13卷 12-32页

作者： Ibrahima Gassama moussa Dabo Emmanuel Tama Samoura Mamadou ndiaye Department of Geology School of Science and Technology Sheikh Anta Diop University Dakar Senegal Géosciences Rennes UMR 6118 CNRS Université de Rennes 1 Campus de Beaulieu Rennes France

The tectonic structures of the Mako area in the Kédougou-Kéniéba inlier (KKI) were mapped with tele-analytical investigation which is validated by field data. This study is based on different images processing in particular: 1) the colored combinations (1 to 5) and panchromatic (8) thematic mapping bands of the Landsat-8 (ETM+) satellite;2) Digital Elevation Model (DEM) image of Space Shuttle Radar Topography Mission (SRTM);3) airborne geophysics (aeromagnetic and radiometric) images. In these images, four major directions of lineaments NS, NNE-SSW, NW-SE and EW would be related to the tectonic structures, have been identified and mapped. Field data confirm these four structural directions and show that most of these lineaments are related to faults, shear and/or thrust zones, or even basic rock dykes. N-S to NE-SW oriented lineaments are more frequent followed by those NW-SE oriented. These two directions of lineaments are generally in correlation with trajectories of major sinistral shear zones in the Mako area. They would be associated with the S2a and S2b schistosities relative to the D2 Eburnean major deformation. They often intersect the E-W oriented lineaments which are less frequent and sometimes folded and crenulated. This E-W oriented linea

Physical and Thermo-Mechanical Properties of Composite Materials Based on Raw Earth and Crushed Palm Leaf Fibers (Borassus aethiopum)

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Materials Sciences and Applications 2024年第9期15卷 358-377页

作者： Mouhamadou Nabi Kane Mapathe ndiaye Pape moussa Touré Adama Dione University College of Architecture of Dakar (CUAD) UFR SI University of Thies This Senegal Laboratory of Mechanics and Modeling UFR SI University of This This Senegal Laboratoire dEnergtique Applique (LEA) Cheikh Anta Diop University Dakar Senegal Institut of Earth Sciences (IST) Universit Cheikh Anta Diop (UCAD) Dakar Senegal

The objective of this study is to seek solutions to reduce the impact of buildings on climate change and to promote the use of local bio-sourced or geo-sourced materials for sustainable construction. Different samples of raw earth from 3 sites were taken in the commune of Mlomp. Geotechnical tests showed that the raw earth samples from sites 2 and 3 have more clay fraction while site 1 contains more sand. The fact of integrating fibers from crushed palm leaves (Borassus aethiopum) (2%, 4% and 6%) into the 3 raw earth samples reduced the mechanical resistance to compression and traction of the 3 raw earths. The experimental results of thermal tests on samples of earth mixtures with crushed Palma leaf fibers show a decrease in thermal conductivity as well as thermal effusivity as the percentages increase (2%, 4% and 6%) of fibers in raw earth for the 3 sites. This shows that this renewable composite material can help improve the thermal insulation of building envelopes.

关键词： Raw Earth Palma Leaf Fibers Ecological Composite Materials Physical Thermo-Mechanical Thermal Conductivity Thermal Effusivity

Utilizing Bayesian Modeling and MCMC for Accurate Characterization of Naturally Occurring Radionuclides Reference Background Levels in Mining Areas

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World Journal of Nuclear Science and Technology 2024年第4期14卷 179-187页

作者： Djicknack Dione Papa Macoumba Faye Nogaye ndiaye moussa Hamady Sy Oumar ndiaye Alassane Traoré Ababacar Sadikhe Ndao Institute Technologies of Nuclear Applied Cheikh Anta Diop University of Dakar Dakar Senegal Department of Physics Faculty of Sciences and Techniques Cheikh Anta Diop University of Dakar Dakar Senegal

Statistical biases may be introduced by imprecisely quantifying background radiation reference levels. It is, therefore, imperative to devise a simple, adaptable approach for precisely describing the reference background levels of naturally occurring radionuclides (NOR) in mining sites. As a substitute statistical method, we suggest using Bayesian modeling in this work to examine the spatial distribution of NOR. For naturally occurring gamma-induced radionuclides like 232Th, 40K, and 238U, statistical parameters are inferred using the Markov Chain Monte Carlo (MCMC) method. After obtaining an accurate subsample using bootstrapping, we exclude any possible outliers that fall outside of the Highest Density Interval (HDI). We use MCMC to build a Bayesian model with the resampled data and make predictions about the posterior distribution of radionuclides produced by gamma irradiation. This method offers a strong and dependable way to describe NOR reference background values, which is important for managing and evaluating radiation risks in mining contexts.

关键词： Radionuclides Bayesian Modeling MCMC HDI 40K 232Th 238U

Meaning of Rocks Basic Enclaves in the Eburnean Granitoids of Mako Area (Kédougou-Kéniéba Inlier, Senegal): Petrogenetic Implications

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International Journal of Geosciences 2021年第1期12卷 39-56页

作者： Ibrahima Gassama moussa Dabo Mamadou ndiaye Emmanuel Tama Samoura Fatou Bop Ndong Université Cheikh Anta Diop de Dakar Département de Géologie Dakar Sénégal

The Mako area, located in eastern Sénégal, constitutes a segment of Paleoproterozoic (Birimian) formations of the Kédougou-Kéniéba Inliers (KKI) in the western part of the West African craton. The basic volcanism of the Birimian formations of the KKI has long been considered to be related to a single magmatic event associated with a Mid Oceanic Ridge Basalts (MORB) setting. The aim of this paper is to demonstrate on the basis of the architectural characteristics of the granitoids dark enclaves, the occurrence of at least two distinct phases of basic Magamtism in the Birimian of the KKI. The methodology consists of a cartography, a petrographic and architectural characterization of the dark enclaves within the Mako granitoids, in order to constrain their spatial and temporal relationships with the granitic magma. The results obtained are compared with those of the bibliography. We have pinpointed two types of enclaves depending o

关键词： Paleoproterozoic Kédougou-Kéniéba Mako Granitoids Basic Enclave Birimian

Modelling and Optimisation of Copper Adsorption in Solution by the Response Surface Method

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Advances in Chemical Engineering and Science 2023年第1期13卷 36-49页

作者： Kalidou Ba Alpha Ousmane Toure Samba ndiaye moussa Diop Falilou Mbacke Sambe Laboratory of Water Energy Environment and Industrial Processes (LE3PI) Higher Polytechnic of Dakar (ESP) Cheikh Anta Diop University (UCAD) Dakar Senegal

Copper is considered a heavy metal that can be toxic at certain concentrations and its presence in water is a potential threat to public health. These heavy metals also contribute to a remarkable degradation of the environment, hence the need for effective treatment methods to remove them. In this study, a mixture of titaniferous sand and calcium silicate was used as adsorbent material to eliminate copper in solution. The calcium silicate was synthesised from fluosilicic acid, which is a by-product of phosphoric acid manufacture. The titaniferous sand is a residue from a mining industry. Both adsorbents were characterised by infrared spectroscopy and X-ray fluorescence to determine their compositions and physicochemical properties. The response surfaces, through the Box-Behnken model, were used to model and optimise various adsorption parameters, namely initial copper concentration (A: 60 - 200 mg/L), adsorbent dose (B: 0.1 - 0.6 g) and pH (C: 4 - 10). The copper removal efficiency (98.92%), after statistical analysis, was obtained under the following optimal conditions: an adsorbent dose of 0.55 g, an initial copper concentration of 197.25 mg/L and a pH of 9.85. The study of the effects of the operating parameters showed that they had a positive effect on the copper removal efficiency.

关键词： Adsorption Calcium Silicate Copper Response Surface Titaniferous Sand