The elimination of vertical transmission of HIV from mother to child is a major global goal. In Senegal, the transmission rate was estimated at 3.2% in 2017. To reduce or even eliminate this transmission, Senegal has ...The elimination of vertical transmission of HIV from mother to child is a major global goal. In Senegal, the transmission rate was estimated at 3.2% in 2017. To reduce or even eliminate this transmission, Senegal has implemented various strategies and programs adopted and applied nationally. Thus access to services for the prevention of mother-to-child transmission of HIV has been extended to the level of the health post (the lowest level of the country’s health pyramid) with a delegation of tasks to paramedical staff (nurse, midwife) in the diagnosis and therapeutic management. Objectives: To describe the epidemiological profile of HIV (Human Immunodeficiency Virus)-positive mothers, to assess the care of children born to HIV-positive mothers, to determine the rate of HIV transmission from mother to child. Patients and Method: We carried out a retrospective, cross-sectional and descriptive study of all live newborns of HIV-positive mothers who gave birth at the Gaspard Kamara Health Center (a level 2 health center in Dakar, Senegal) between January 1, 2015 and December 31, 2018. The data were collected from prevention of mother-to-child transmission (PMTCT) prenatal follow-up registers and files, delivery files and registers, and neonatology and pediatric follow-up files, and exploited using the Epi info 7 software. Results: There were 98 children of seropositive mothers. The epidemiological profile of the HIV-positive woman was that of a young woman aged between 16 and 43 with an average of 31.31 years, pauciparous (>65% of cases) from Dakar center (>75% of cases), housewife with a low socio-economic level (63.1% of cases), married in almost all cases, with HIV profile (in almost all cases) and diagnosed before pregnancy (51.02%). The analysis of the children’s data revealed a predominance of girls (52.04%) with a good birth weight (2964g on average) and a pregnancy carried to term in more than 95% of cases. ARV prophylaxis was almost entirely respected with triple therapy (AZT + 3TC + NVP) in a fixed combination as protocol. Protected breastfeeding (80.21%), including 6 months of exclusive protected breastfeeding, was the rule for the mode of feeding. Three children were diagnosed positive with PCR1 as with serology (3.06%). Discussion and Conclusion: the initiatives and strategies put in place in Senegal have enabled a significant reduction in mother-to-child transmission of HIV and deserve to be supported by insisting on primary prevention, programming and good follow-up of pregnancies, and a good support for HIV-positive women.展开更多
Objective: To describe the epidemiological, clinical and prognostic factors and assess treatment of placental abruption in the obstetrics gynecology department of the Dakar Principal Hospital. Patients and Method: We ...Objective: To describe the epidemiological, clinical and prognostic factors and assess treatment of placental abruption in the obstetrics gynecology department of the Dakar Principal Hospital. Patients and Method: We carried out a retrospective observational study of 130 successive cases of placental abruption, which occurred from January 2015 to December 2017 at the Level 3 Maternity Unit of the Dakar Principal Hospital. Data were collected from non-computerized obstetric records and analyzed using Excel and Epi info software. Results: There were 130 cases of placental abruption, that is a prevalence of 1.5%. The average age of onset of placental abruption was 30 years. The history of hypertension concerned 32.3% of patients, the average gestational age of 32.5 weeks at the time of diagnosis, grade 3 of Sher was found in 48.5% of cases. The outcome of the pregnancy was a caesarean section in 79.2% of cases, the average weight of newborns was 2058 g. The management of the complications required a blood transfusion and intensive care. A haemostasis hysterectomy was performed in 6.2% of cases. Stillbirth rate was 53.7% and maternal mortality was zero. Discussion and Conclusion: Placental abruption, a severe complication of pregnancy, is associated with high perinatal morbidity and mortality linked to the severity of the clinical picture, despite an improved maternal prognosis.展开更多
This paper shows geometric aspects of rock masses in the Senegalese side of Kédougou-Kéniéba inlier. The studies are done in one part on sedimentary rocks (represented by sandstones) with stratification...This paper shows geometric aspects of rock masses in the Senegalese side of Kédougou-Kéniéba inlier. The studies are done in one part on sedimentary rocks (represented by sandstones) with stratification and on the other part in igneous rocks (represented by basalts). Geometric studies are the fractal configuration and the scale effect. Scale effect is stud- ied by comparing the results of mechanical tests done in the laboratory and on outcrops. For all samples, laboratory pa- rameters are higher than values of field. In this paper, scale effect is characterized by the decrease of mechanical pa- rameters from laboratory samples to field. The scale coefficient is defined and characterizes the relation between me- chanical properties. More importantly, the scale effect is more significant. This scale effect depends largely on the rock anisotropy. The anisotropy depends on the fracturation and the filling. The scale effect takes into account the fracturation, the filling minerals and their diversity which define the complexity of the rock. The anisotropy is complex;the impact of scale effect traduced by an increase of scale coefficient is the highest. Configuration of discontinuities also defines fractal geometry. This fractal aspect appears on the asperities, the spacing and the apertures of discontinuities. The fractal dimension is different from a parameter to another. All these two parameters estimate the stage of fracturation of the rock in a geological system and depend one on another if they are studied in the same element.展开更多
The Sabodala gold deposit in the Mako volcanic Belt (SE-Senegal, West African Craton) occurs in mafic and ultramafic rocks overlain by clastic sedimentary rocks and felsic volcanic-volcaniclastic sequences. It is a st...The Sabodala gold deposit in the Mako volcanic Belt (SE-Senegal, West African Craton) occurs in mafic and ultramafic rocks overlain by clastic sedimentary rocks and felsic volcanic-volcaniclastic sequences. It is a structurally controlled mesothermal vein gold deposit developed in deformed rocks units near the Falombo pluton. The Sabodala Goldfield comprises several faults systems striking N-S to NE-SW. New structural evolution consisting of both thrusting and transcurrent events has been defined for the Sabodala Goldfield. The majority of the gold at Sabodala occurs on the western flank of a large, doubling plunging dome (the Sabodala Antiform) and is also associated with sinistral wrenching that overprints early structures within the Sabodala Mine. The gold bearing veins are hosted by flat lying and NW-trending shear zones. The NW-trending faults acted as transfers syn-gold mineralization, although only discrete segments of these faults were active during the main stage of gold mineralization. Late exhumation resulted in extension along fault zones was responsible for the juxtaposition of medium and low grade metamorphic rocks. The granitic suite of the Falombo pluton is linked to exhumation. Final dextral transpression postdating exhumation produced shearing and folding. Gold lodes developed during brittle deformation are associated with high fluid pressures in a northwest-southeast shortening regime. These are termed mainly the Sabodala deposit, and secondary the Niakafiri and Masato deposits.展开更多
This work presents the behavior of Segou sandstones in the laboratory and in the field conditions. Four types of sandstone are collected in the northern part of the Madina Kouta basin (eastern Senegal). These types of...This work presents the behavior of Segou sandstones in the laboratory and in the field conditions. Four types of sandstone are collected in the northern part of the Madina Kouta basin (eastern Senegal). These types of specimens are the white sandstones, the red sandstones, the purple sandstones and the sandstones with intercalation of pelites. Uniaxial tests are carried out on these specimens of sandstones. The Young Moduli (E) and the Uniaxial Compression Strengths (Rc) are higher for the white sandstone. Values of the mechanical parameters decrease slightly for red sandstones due to an increase of the amount of pelites in the composition of the rock. Decrease of mechanical parameters is more important for the purple facies due to an important network of fractures. The facies with weaker characteristics corresponds to the sandstones with intercalation of pelites. This is due to the soft nature of the pelites. The slope stability of the Cliff sides depends also on to these characteristics.展开更多
This work shows the Kédougou-Kéniéba inlier (eastern Senegal) pillow lavas behavior from laboratory to field. Some uniaxial tests are carried out on five types of specimens of pillow lavas. These types ...This work shows the Kédougou-Kéniéba inlier (eastern Senegal) pillow lavas behavior from laboratory to field. Some uniaxial tests are carried out on five types of specimens of pillow lavas. These types of specimens are: macroscopicly healthy rock, fractured rock without filling, fractured rock filled with epidote, chlorite and calcite and rocks with tension crack filled with quartz. The Young moduli and the uniaxial compression strength are good for the healthy rock. The Young moduli fall slightly for facies with horizontal cracks while uniaxial compression strength (Rc) varies slightly. For filled fractured specimens, Rc and Young modulus (E) decrease remarkably. Decreases are most important for cracks filled with epidote, chlorite and calcite than with quartz. That is due to the differences of rigidity between these materials. Also, the slope stability of hillsides in this area depends on to these characteristics.展开更多
The volcanic tuffs of Senegal-Oriental in Mako area are produced during a calc-alkaline volcanism which occurs in this region and which is dated from about 2.3 - 1.95 Ga. Despite their altered appearance, the X-Ray di...The volcanic tuffs of Senegal-Oriental in Mako area are produced during a calc-alkaline volcanism which occurs in this region and which is dated from about 2.3 - 1.95 Ga. Despite their altered appearance, the X-Ray diffractions show mineral paragenesis: Quartz-Kaolinite-Illite and an important amorphous phase. On the Ternary Keil-Rankin diagram for the CaO-SiO2-Al2O3 the volcanic tuffs of Mako area are situated between pozzolan and the fly ash. The difference between silica and lime is greater than 34% in these volcanic tuffs. In this study, they have been mixed with Portland cement to obtain pozzolanic cements respectively with 20%, 30%, 35% and 40% of addition of volcanic tuffs. The pozzolanic reactivity is highlighted by the compressive strength increase until 90 days of conservation in water. It supposes that the vitreous phase of the volcanic tuffs reacts with the free CaO (CaOf) of Portland cement to produce new hydrated minerals. This study has a positive economic and environmental impact. Because the time of grinding of pozzolanic cements is reduced. Also, the addition of volcanic tuffs reduces the production of clinker, then the CO2 emission.展开更多
The Cenozoic alkaline volcanism of the Senegalo-Mauritania sedimentary basin presents an episodic long-lasting volcanic activity from the Eocene-Oligocene boundary up to the Quaternary. Two volcanic episodes are usual...The Cenozoic alkaline volcanism of the Senegalo-Mauritania sedimentary basin presents an episodic long-lasting volcanic activity from the Eocene-Oligocene boundary up to the Quaternary. Two volcanic episodes are usually distinguished on stratigraphical grounds: a Miocene one and a Quaternary one separated by a period of quiescence of several million years corresponding to the main phase of lateritic weathering. The Tertiary lavas are highly silica-undersaturated alkaline rocks ranging from nephelinites to basanites. They contain nepheline and fassaite-type clinopyroxene in their mineralogy. The Quaternary lavas are more evolved with Hy-normative in comparison to the Tertiary ones;they are composed of basanites and medium to coarser-grained dolerites. The distribution of the REE and other incompatible elements are typical of alkaline lavas with generally strong LREE enrichment without significant Eu anomaly. The Cenozoic Cap-Vert lavas have OIB (oceanic islands basalts)-affinities as shown by their relatively radiogenic Nd and unradiogenic Sr characters closed to the HIMU-OIB. This suggests a HIMU-type end member in the magma sources which is fairly comparable to those erupted in the Canaries and Cape Verde archipelagoes during the same period.展开更多
In Senegal, rock mechanic studies began in last four years and were a very new engineering domain. So, the first stage is to characterize geological materials. It is on this way that this work is done. This paper anal...In Senegal, rock mechanic studies began in last four years and were a very new engineering domain. So, the first stage is to characterize geological materials. It is on this way that this work is done. This paper analyzes geomechanical parameters of sandstones of Dindifélo and basalt of Bafoundou belonging to the Proterozoic rocks domain of eastern Senegal. By Rock Mass Rating (RMR) and Geological Strength Index (GSI), sandstones of the Dindifello Cliff show fair to poor characteristics while basalts of the hills of Bafoundou are fair quality. In addition to the qualities of rock mass, Young moduli, uniaxial compressive strengths and tensile strength of rock mass are also defined using Rock Quality Designation (RQD) GSI, RMR. Hoek-Brown parameters m and a, depend both on the fracturation and the content fine in the rock. Values of mechanical parameters are different when deduced from RMR, GSI and from intact rock laboratory test. Those differences are due to variables taken account. The variation depends also on the quality of the rock. Statistical analysis shows possible unstabilities which depend on rock mass parameters but with acceptable probability of failure. Probability of failure is the highest when deducing from Mohr criterion than from Hoek-Brown criterion.展开更多
The Bangaani area is located in the northwestern part of the Karthala Massif on the island of Grande Comore, about 10 km from the capital Moroni. It is essentially constituted of basalt plateaus outcropping in the for...The Bangaani area is located in the northwestern part of the Karthala Massif on the island of Grande Comore, about 10 km from the capital Moroni. It is essentially constituted of basalt plateaus outcropping in the form of pahoehoe and aa lava flows or in the form of massive vesicular or non vesicular basalt flows. Petrographic analysis of the massive basalts studied shows a porphyritic microlitic texture marked by the successive crystallization of olivines, opaque minerals, clinopyroxenes and plagioclases in a relatively abundant mesostasis. This crystallization sequence is typical of a high pressure environment corresponding to primary alkaline magmas. The geochemical study of major and trace elements shows that the basalts studied are under saturated in silica (47.24%) but rich in alkali (2.26%) and titanium (2.66%). They correspond to intraplate alkaline basalts of type oceanic island basalts (OIB) and present a primary character marked by relatively high contents of magnesium (6.69%), chromium (151.23 ppm), nickel (107.53 ppm) and scandium (27.15 ppm). The REE and multi-element diagrams confirm that the Karthala basalts are alkaline basalts of type OIB by their enrichment in LILE and their depleted character in HREE and HFSE. In terms of isotopic ratios, they are comparable to HIMU and EM I.展开更多
文摘The elimination of vertical transmission of HIV from mother to child is a major global goal. In Senegal, the transmission rate was estimated at 3.2% in 2017. To reduce or even eliminate this transmission, Senegal has implemented various strategies and programs adopted and applied nationally. Thus access to services for the prevention of mother-to-child transmission of HIV has been extended to the level of the health post (the lowest level of the country’s health pyramid) with a delegation of tasks to paramedical staff (nurse, midwife) in the diagnosis and therapeutic management. Objectives: To describe the epidemiological profile of HIV (Human Immunodeficiency Virus)-positive mothers, to assess the care of children born to HIV-positive mothers, to determine the rate of HIV transmission from mother to child. Patients and Method: We carried out a retrospective, cross-sectional and descriptive study of all live newborns of HIV-positive mothers who gave birth at the Gaspard Kamara Health Center (a level 2 health center in Dakar, Senegal) between January 1, 2015 and December 31, 2018. The data were collected from prevention of mother-to-child transmission (PMTCT) prenatal follow-up registers and files, delivery files and registers, and neonatology and pediatric follow-up files, and exploited using the Epi info 7 software. Results: There were 98 children of seropositive mothers. The epidemiological profile of the HIV-positive woman was that of a young woman aged between 16 and 43 with an average of 31.31 years, pauciparous (>65% of cases) from Dakar center (>75% of cases), housewife with a low socio-economic level (63.1% of cases), married in almost all cases, with HIV profile (in almost all cases) and diagnosed before pregnancy (51.02%). The analysis of the children’s data revealed a predominance of girls (52.04%) with a good birth weight (2964g on average) and a pregnancy carried to term in more than 95% of cases. ARV prophylaxis was almost entirely respected with triple therapy (AZT + 3TC + NVP) in a fixed combination as protocol. Protected breastfeeding (80.21%), including 6 months of exclusive protected breastfeeding, was the rule for the mode of feeding. Three children were diagnosed positive with PCR1 as with serology (3.06%). Discussion and Conclusion: the initiatives and strategies put in place in Senegal have enabled a significant reduction in mother-to-child transmission of HIV and deserve to be supported by insisting on primary prevention, programming and good follow-up of pregnancies, and a good support for HIV-positive women.
文摘Objective: To describe the epidemiological, clinical and prognostic factors and assess treatment of placental abruption in the obstetrics gynecology department of the Dakar Principal Hospital. Patients and Method: We carried out a retrospective observational study of 130 successive cases of placental abruption, which occurred from January 2015 to December 2017 at the Level 3 Maternity Unit of the Dakar Principal Hospital. Data were collected from non-computerized obstetric records and analyzed using Excel and Epi info software. Results: There were 130 cases of placental abruption, that is a prevalence of 1.5%. The average age of onset of placental abruption was 30 years. The history of hypertension concerned 32.3% of patients, the average gestational age of 32.5 weeks at the time of diagnosis, grade 3 of Sher was found in 48.5% of cases. The outcome of the pregnancy was a caesarean section in 79.2% of cases, the average weight of newborns was 2058 g. The management of the complications required a blood transfusion and intensive care. A haemostasis hysterectomy was performed in 6.2% of cases. Stillbirth rate was 53.7% and maternal mortality was zero. Discussion and Conclusion: Placental abruption, a severe complication of pregnancy, is associated with high perinatal morbidity and mortality linked to the severity of the clinical picture, despite an improved maternal prognosis.
文摘This paper shows geometric aspects of rock masses in the Senegalese side of Kédougou-Kéniéba inlier. The studies are done in one part on sedimentary rocks (represented by sandstones) with stratification and on the other part in igneous rocks (represented by basalts). Geometric studies are the fractal configuration and the scale effect. Scale effect is stud- ied by comparing the results of mechanical tests done in the laboratory and on outcrops. For all samples, laboratory pa- rameters are higher than values of field. In this paper, scale effect is characterized by the decrease of mechanical pa- rameters from laboratory samples to field. The scale coefficient is defined and characterizes the relation between me- chanical properties. More importantly, the scale effect is more significant. This scale effect depends largely on the rock anisotropy. The anisotropy depends on the fracturation and the filling. The scale effect takes into account the fracturation, the filling minerals and their diversity which define the complexity of the rock. The anisotropy is complex;the impact of scale effect traduced by an increase of scale coefficient is the highest. Configuration of discontinuities also defines fractal geometry. This fractal aspect appears on the asperities, the spacing and the apertures of discontinuities. The fractal dimension is different from a parameter to another. All these two parameters estimate the stage of fracturation of the rock in a geological system and depend one on another if they are studied in the same element.
文摘The Sabodala gold deposit in the Mako volcanic Belt (SE-Senegal, West African Craton) occurs in mafic and ultramafic rocks overlain by clastic sedimentary rocks and felsic volcanic-volcaniclastic sequences. It is a structurally controlled mesothermal vein gold deposit developed in deformed rocks units near the Falombo pluton. The Sabodala Goldfield comprises several faults systems striking N-S to NE-SW. New structural evolution consisting of both thrusting and transcurrent events has been defined for the Sabodala Goldfield. The majority of the gold at Sabodala occurs on the western flank of a large, doubling plunging dome (the Sabodala Antiform) and is also associated with sinistral wrenching that overprints early structures within the Sabodala Mine. The gold bearing veins are hosted by flat lying and NW-trending shear zones. The NW-trending faults acted as transfers syn-gold mineralization, although only discrete segments of these faults were active during the main stage of gold mineralization. Late exhumation resulted in extension along fault zones was responsible for the juxtaposition of medium and low grade metamorphic rocks. The granitic suite of the Falombo pluton is linked to exhumation. Final dextral transpression postdating exhumation produced shearing and folding. Gold lodes developed during brittle deformation are associated with high fluid pressures in a northwest-southeast shortening regime. These are termed mainly the Sabodala deposit, and secondary the Niakafiri and Masato deposits.
文摘This work presents the behavior of Segou sandstones in the laboratory and in the field conditions. Four types of sandstone are collected in the northern part of the Madina Kouta basin (eastern Senegal). These types of specimens are the white sandstones, the red sandstones, the purple sandstones and the sandstones with intercalation of pelites. Uniaxial tests are carried out on these specimens of sandstones. The Young Moduli (E) and the Uniaxial Compression Strengths (Rc) are higher for the white sandstone. Values of the mechanical parameters decrease slightly for red sandstones due to an increase of the amount of pelites in the composition of the rock. Decrease of mechanical parameters is more important for the purple facies due to an important network of fractures. The facies with weaker characteristics corresponds to the sandstones with intercalation of pelites. This is due to the soft nature of the pelites. The slope stability of the Cliff sides depends also on to these characteristics.
文摘This work shows the Kédougou-Kéniéba inlier (eastern Senegal) pillow lavas behavior from laboratory to field. Some uniaxial tests are carried out on five types of specimens of pillow lavas. These types of specimens are: macroscopicly healthy rock, fractured rock without filling, fractured rock filled with epidote, chlorite and calcite and rocks with tension crack filled with quartz. The Young moduli and the uniaxial compression strength are good for the healthy rock. The Young moduli fall slightly for facies with horizontal cracks while uniaxial compression strength (Rc) varies slightly. For filled fractured specimens, Rc and Young modulus (E) decrease remarkably. Decreases are most important for cracks filled with epidote, chlorite and calcite than with quartz. That is due to the differences of rigidity between these materials. Also, the slope stability of hillsides in this area depends on to these characteristics.
文摘The volcanic tuffs of Senegal-Oriental in Mako area are produced during a calc-alkaline volcanism which occurs in this region and which is dated from about 2.3 - 1.95 Ga. Despite their altered appearance, the X-Ray diffractions show mineral paragenesis: Quartz-Kaolinite-Illite and an important amorphous phase. On the Ternary Keil-Rankin diagram for the CaO-SiO2-Al2O3 the volcanic tuffs of Mako area are situated between pozzolan and the fly ash. The difference between silica and lime is greater than 34% in these volcanic tuffs. In this study, they have been mixed with Portland cement to obtain pozzolanic cements respectively with 20%, 30%, 35% and 40% of addition of volcanic tuffs. The pozzolanic reactivity is highlighted by the compressive strength increase until 90 days of conservation in water. It supposes that the vitreous phase of the volcanic tuffs reacts with the free CaO (CaOf) of Portland cement to produce new hydrated minerals. This study has a positive economic and environmental impact. Because the time of grinding of pozzolanic cements is reduced. Also, the addition of volcanic tuffs reduces the production of clinker, then the CO2 emission.
文摘The Cenozoic alkaline volcanism of the Senegalo-Mauritania sedimentary basin presents an episodic long-lasting volcanic activity from the Eocene-Oligocene boundary up to the Quaternary. Two volcanic episodes are usually distinguished on stratigraphical grounds: a Miocene one and a Quaternary one separated by a period of quiescence of several million years corresponding to the main phase of lateritic weathering. The Tertiary lavas are highly silica-undersaturated alkaline rocks ranging from nephelinites to basanites. They contain nepheline and fassaite-type clinopyroxene in their mineralogy. The Quaternary lavas are more evolved with Hy-normative in comparison to the Tertiary ones;they are composed of basanites and medium to coarser-grained dolerites. The distribution of the REE and other incompatible elements are typical of alkaline lavas with generally strong LREE enrichment without significant Eu anomaly. The Cenozoic Cap-Vert lavas have OIB (oceanic islands basalts)-affinities as shown by their relatively radiogenic Nd and unradiogenic Sr characters closed to the HIMU-OIB. This suggests a HIMU-type end member in the magma sources which is fairly comparable to those erupted in the Canaries and Cape Verde archipelagoes during the same period.
文摘In Senegal, rock mechanic studies began in last four years and were a very new engineering domain. So, the first stage is to characterize geological materials. It is on this way that this work is done. This paper analyzes geomechanical parameters of sandstones of Dindifélo and basalt of Bafoundou belonging to the Proterozoic rocks domain of eastern Senegal. By Rock Mass Rating (RMR) and Geological Strength Index (GSI), sandstones of the Dindifello Cliff show fair to poor characteristics while basalts of the hills of Bafoundou are fair quality. In addition to the qualities of rock mass, Young moduli, uniaxial compressive strengths and tensile strength of rock mass are also defined using Rock Quality Designation (RQD) GSI, RMR. Hoek-Brown parameters m and a, depend both on the fracturation and the content fine in the rock. Values of mechanical parameters are different when deduced from RMR, GSI and from intact rock laboratory test. Those differences are due to variables taken account. The variation depends also on the quality of the rock. Statistical analysis shows possible unstabilities which depend on rock mass parameters but with acceptable probability of failure. Probability of failure is the highest when deducing from Mohr criterion than from Hoek-Brown criterion.
文摘The Bangaani area is located in the northwestern part of the Karthala Massif on the island of Grande Comore, about 10 km from the capital Moroni. It is essentially constituted of basalt plateaus outcropping in the form of pahoehoe and aa lava flows or in the form of massive vesicular or non vesicular basalt flows. Petrographic analysis of the massive basalts studied shows a porphyritic microlitic texture marked by the successive crystallization of olivines, opaque minerals, clinopyroxenes and plagioclases in a relatively abundant mesostasis. This crystallization sequence is typical of a high pressure environment corresponding to primary alkaline magmas. The geochemical study of major and trace elements shows that the basalts studied are under saturated in silica (47.24%) but rich in alkali (2.26%) and titanium (2.66%). They correspond to intraplate alkaline basalts of type oceanic island basalts (OIB) and present a primary character marked by relatively high contents of magnesium (6.69%), chromium (151.23 ppm), nickel (107.53 ppm) and scandium (27.15 ppm). The REE and multi-element diagrams confirm that the Karthala basalts are alkaline basalts of type OIB by their enrichment in LILE and their depleted character in HREE and HFSE. In terms of isotopic ratios, they are comparable to HIMU and EM I.