Abderamane Moussa - Academia.edu (original) (raw)
Papers by Abderamane Moussa
Comptes Rendus. Géoscience
Les grès ordoviciens du plateau de l'Ennedi, NE du Tchad
Geological Society, London, Special Publications
The Ordovician of North and West Africa comprises three main transgressive–regressive sequences u... more The Ordovician of North and West Africa comprises three main transgressive–regressive sequences understood as ‘second-order’ cycles of 10–15 myr duration. Tide- to wave-dominated shallow-marine clastic successions, preserving incidental bryozoan carbonates to the north, include fluvial deposits over the most proximal southern stretches of the platform. The boundary with Cambrian strata remains unclear but the latter are progressively less represented to the south in the undifferentiated ‘Cambro-Ordovician’. To the north, graptolites, brachiopods and trilobites combined with palynomorphs provide a robust biostratigraphic frame. Maximum flooding intervals occurred in the early to middle Tremadocian, middle Darriwilian and middle to late Katian. Two events interfered with an overall long-term transgressive trend. The ‘intra-Arenig’ (late Floian?) tectonic event highlighted palaeohighs coinciding with Paleoproterozoic basements. Gondwanan drainage basins were reorganized, which had an i...
Quaternary Science Reviews
Livraison de fourrage à Yao. L'augmentation des populations sédentaires et transhumantes et de le... more Livraison de fourrage à Yao. L'augmentation des populations sédentaires et transhumantes et de leur bétail accroît fortement la pression sur les ressources (Yao, février 2016). © CNRS/M. Schuster p. 4 de couverture Multifonctionnalité de l'espace en bordure du lac Fitri (Gamsa, janvier 2016). Les jardins maraîchers et la pêche entravent le passage saisonnier des troupeaux vers les bourgoutières sur les îles. © CNRS/C. Raimond La loi du 1 er juillet 1992 (code de la propriété intellectuelle, première partie) n'autorisant, aux termes des alinéas 2 et 3 de l'article L. 122-5, d'une part, que les « copies ou reproductions strictement réservées à l'usage du copiste et non destinées à une utilisation collective » et, d'autre part, que les analyses et les courtes citations dans le but d'exemple ou d'illustration, « toute représentation ou reproduction intégrale ou partielle faite sans le consentement de l'auteur ou de ses ayants droit ou ayants cause, est illicite » (alinéa 1 er de l'article L. 122-4). Cette représentation ou reproduction, par quelque procédé que ce soit, constituerait donc une contrefaçon passible des peines prévues au titre III de la loi précitée.
African Journal of Environmental Science and Technology, 2021
The detailed sedimentary study of the deposit sequences of the ancient hominid sector (Sahelanthr... more The detailed sedimentary study of the deposit sequences of the ancient hominid sector (SahelanthropustchadensisalisToumaï) of Toros-Menalla, presented here addresses new aspects of the sedimentary geology of the Chad Basin through an original field study of Moi-sediments: Pliocene of the northern basin of CHAD. This is an original contribution that sheds light on new knowledge of sedimentary series of fluvio-lacustrine and aeolian origin in the Djourab desert which are essential for understanding the paleoenvironments and paleoclimates of Chad, the Sahara and Africa. Aged from the Terminal Miocene to the present day, these deposits which constitute the last stages of the filling of this basin are exclusively of the continental type and concern in the broad sense the following four major sedimentary systems: Fluvial, deltaic, lacustrine and aeolian. From a lithological point of view, these sedimentary series are very heterogeneous and include sandstones, sands, clays and diatomites.
Terrestrial bipedal locomotion is one of the key adaptations defining the hominin clade. Evidence... more Terrestrial bipedal locomotion is one of the key adaptations defining the hominin clade. Evidences of undisputed bipedalism are known from postcranial remains of late Miocene hominins as soon as 6 Ma in eastern Africa. Bipedality of Sahelanthropus tchadensis was hitherto documented at 7 Ma in central Africa (Chad) by cranial evidence. Here, we present the first postcranial evidence of the locomotor behavior of the Chadian hominin with new insights on bipedalism at the early stage of our evolutionary history. The original material was discovered at locality TM 266 (Toros-Menalla fossiliferous area), and consists in one left femur and two antimeric ulnae. These new findings confirm that hominins were already terrestrial biped relatively soon after the human-chimpanzee divergence but also suggest that careful climbing arboreal behaviors was still a significant part of their locomotor repertoire.
Quaternary International, 2016
International Journal of Water Resources and Environmental Engineering, 2017
This work aimed to contribute to knowledge improvement of the great Lake ecosystems of Chad, prec... more This work aimed to contribute to knowledge improvement of the great Lake ecosystems of Chad, precisely that of the Lakes of Ounianga using bathymetric statements on water levels and the in situ analysis of physicochemical parameters of the lake's waters. Bathymetric surveys facilitated characterization of the morphology of the bottom of the lakes with depths that vary from 0 to-27 m and 0 to-5.7 m for Yoan and Teli Lakes, respectively. With regards to water physio-chemistry, the temperature of the Teli Lake water measuring up to 0.5 m varied from 20.8 to 36°C, while that of Lake Yoan varied from 10.50 to 32.90°C, with an average of 22 and 27°C. The conductivity values oscillated between 69 and 111,700 μS/cm for the Lake Teli and 100 to 64,000 μS/cm for the Lake Yoan. This document illustrates the techniques used in the investigation of a lake whose study constitutes a wide field of continental hydrology.
Journal of African Earth Sciences, 2016
Lake Chad sedimentation and environments during the late Miocene and Pliocene: new evidence from ... more Lake Chad sedimentation and environments during the late Miocene and Pliocene: new evidence from mineralogy and chemistry of the Bol core sediments
Palaeogeography, Palaeoclimatology, Palaeoecology, 2016
cited By 0International audienceno abstrac
Palaeogeography, Palaeoclimatology, Palaeoecology, 2015
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Earth and Planetary Science Letters, 2010
Comptes Rendus Geoscience, 2009
Since the mid 1990s, the Mission paléoanthropologique francotchadienne (MPFT) conducts yearly pal... more Since the mid 1990s, the Mission paléoanthropologique francotchadienne (MPFT) conducts yearly paleontological field investigations of the Miocene-Pliocene of the Chad Basin. This article synthesizes some of the results of the MPFT, with focus on the Chad Basin development during the Neogene. We propose an overview of the depositional paleoenvironments of this part of Africa at different scales of time and space, based on a multidisciplinary approach (sedimentary geology, geomorphology, geophysic, numerical simulations and geochronology). The Miocene-Pliocene paleoenvironments are examined through the sedimentary archives of the early hominids levels and the Holocene Lake Mega-Chad episode illustrates the last major paleoenvironmental change in this area. The sedimentary record of the Chad Basin since the Late Miocene can be schematized as the result of recurrent interactions from lake to desert environments. To cite this article: M.
Revue Française de Photogrammétrie et de Télédétection, 2014
Megalake Chad (350,000 km2), the largest paleo-lake of the Sahara-Sahel area, is one of the most ... more Megalake Chad (350,000 km2), the largest paleo-lake of the Sahara-Sahel area, is one of the most emblematic marker of the hydroclimatic changes that occurred during the African Humid Period (AHP; ca. 11,500 — 5,000 years BP) in subtropical Africa. From field surveys, the existence of Megalake Chad is well demonstrated by widespread typical lake deposits. However, considering the very large size of this paleo-lake, it is best evidenced and understood from space. Conspicuous paleo-littoral features distributed along hundreds of kilometers are clearly visible on second generation satellite images. These features represent major archives of the Megalake Chad and of the climate during the AHP. This paper is the first attempt to investigate the paleo-littoral of Megalake Chad with very high resolution satellite imagery. A Pléiades scene (images and DEM) is used to characterize the fossil sand spit of the Goz Kerki, which is one of the most representative and best preserved littoral featur...
Http Www Theses Fr, 2010
En Afrique et plus particulierement dans le bassin du Tchad, la dynamique des paleoenvironnements... more En Afrique et plus particulierement dans le bassin du Tchad, la dynamique des paleoenvironnements durant le Mio-Pliocene a joue un role crucial dans l’histoire de l’emergence et de l’evolution des hominides anciens. Ce travail tente de reconstituer les environnements de depot du bassin du Tchad pendant les 7 derniers millions d’annees et de faire le lien entre les facies arenitiques de bordures et les facies argileux au centre du bassin. Une attention particuliere est accordee aux environnements et a la dynamique des sites a hominides de la partie Nord du bassin localises dans une zone cle qui a joue un role de tampon oscillant au gre des fluctuations hydroclimatiques. Il tente egalement de retracer l’histoire generale du lac Tchad depuis sa mise en place il y a au moins 7 millions d’annees jusqu’au Quaternaire terminal avec une etude detaillee du dernier colmatage de la plaine alluviale du Chari. Les facies decrits s’echelonnent du lacustre a l’eolien en passant par les facies margino-littoraux deltaiques ou peri-lacustres. Pour la premiere fois, est donne l’âge de l’installation du systeme lacustre du bassin du Tchad. Si la stratigraphie generale du bassin est connue depuis les annees soixante, l’interpretation des facies de ces series sedimentaires n’a jusqu’a present pas fait l’objet d’etudes specifiques notamment en raison de mauvaises conditions d’affleurements et de la difficulte de correler les affleurements entre eux tant en âge qu’en facies. Cette these est une contribution originale a la connaissance de series sedimentaires du bassin du Tchad. Elle apporte de nouvelles donnees pour la comprehension des paleoenvironnements et des paleoclimats du Tchad, du Sahara et de l’Afrique depuis le Miocene terminal jusqu’a l’actuel.
Quaternary Research, 2010
Holocene Lake Mega-Chad (LMC) was the largest late Quaternary water-body in Africa. The developme... more Holocene Lake Mega-Chad (LMC) was the largest late Quaternary water-body in Africa. The development of this giant paleo-lake is related to a northward shift of the isohyetes interpreted as evidence for an enhanced Monsoon (African Humid Period). Numerous preserved coastal features have been described all around the LMC shore. Such features reveal the main paleo-hydrodynamical tendencies. In the context of a closed water-body like LMC, hydrodynamics are forced mainly by winds. We use a three-dimensional numerical model (SYMPHONIE) to simulate the mean hydrodynamics in LMC under both Harmattan-like (northeasterly trade winds) and Monsoon-like (southwesterly winds) forcings. The northern part of LMC displays coastal features, such as sand spits, that are consistent with the simulations forced by Harmattan-like winds. Geomorphic features related to Monsoon-driven hydrodynamics are not clearly expressed. They could have developed during the early stage of LMC but subsequently reworked. A...
Comptes Rendus. Géoscience
Les grès ordoviciens du plateau de l'Ennedi, NE du Tchad
Geological Society, London, Special Publications
The Ordovician of North and West Africa comprises three main transgressive–regressive sequences u... more The Ordovician of North and West Africa comprises three main transgressive–regressive sequences understood as ‘second-order’ cycles of 10–15 myr duration. Tide- to wave-dominated shallow-marine clastic successions, preserving incidental bryozoan carbonates to the north, include fluvial deposits over the most proximal southern stretches of the platform. The boundary with Cambrian strata remains unclear but the latter are progressively less represented to the south in the undifferentiated ‘Cambro-Ordovician’. To the north, graptolites, brachiopods and trilobites combined with palynomorphs provide a robust biostratigraphic frame. Maximum flooding intervals occurred in the early to middle Tremadocian, middle Darriwilian and middle to late Katian. Two events interfered with an overall long-term transgressive trend. The ‘intra-Arenig’ (late Floian?) tectonic event highlighted palaeohighs coinciding with Paleoproterozoic basements. Gondwanan drainage basins were reorganized, which had an i...
Quaternary Science Reviews
Livraison de fourrage à Yao. L'augmentation des populations sédentaires et transhumantes et de le... more Livraison de fourrage à Yao. L'augmentation des populations sédentaires et transhumantes et de leur bétail accroît fortement la pression sur les ressources (Yao, février 2016). © CNRS/M. Schuster p. 4 de couverture Multifonctionnalité de l'espace en bordure du lac Fitri (Gamsa, janvier 2016). Les jardins maraîchers et la pêche entravent le passage saisonnier des troupeaux vers les bourgoutières sur les îles. © CNRS/C. Raimond La loi du 1 er juillet 1992 (code de la propriété intellectuelle, première partie) n'autorisant, aux termes des alinéas 2 et 3 de l'article L. 122-5, d'une part, que les « copies ou reproductions strictement réservées à l'usage du copiste et non destinées à une utilisation collective » et, d'autre part, que les analyses et les courtes citations dans le but d'exemple ou d'illustration, « toute représentation ou reproduction intégrale ou partielle faite sans le consentement de l'auteur ou de ses ayants droit ou ayants cause, est illicite » (alinéa 1 er de l'article L. 122-4). Cette représentation ou reproduction, par quelque procédé que ce soit, constituerait donc une contrefaçon passible des peines prévues au titre III de la loi précitée.
African Journal of Environmental Science and Technology, 2021
The detailed sedimentary study of the deposit sequences of the ancient hominid sector (Sahelanthr... more The detailed sedimentary study of the deposit sequences of the ancient hominid sector (SahelanthropustchadensisalisToumaï) of Toros-Menalla, presented here addresses new aspects of the sedimentary geology of the Chad Basin through an original field study of Moi-sediments: Pliocene of the northern basin of CHAD. This is an original contribution that sheds light on new knowledge of sedimentary series of fluvio-lacustrine and aeolian origin in the Djourab desert which are essential for understanding the paleoenvironments and paleoclimates of Chad, the Sahara and Africa. Aged from the Terminal Miocene to the present day, these deposits which constitute the last stages of the filling of this basin are exclusively of the continental type and concern in the broad sense the following four major sedimentary systems: Fluvial, deltaic, lacustrine and aeolian. From a lithological point of view, these sedimentary series are very heterogeneous and include sandstones, sands, clays and diatomites.
Terrestrial bipedal locomotion is one of the key adaptations defining the hominin clade. Evidence... more Terrestrial bipedal locomotion is one of the key adaptations defining the hominin clade. Evidences of undisputed bipedalism are known from postcranial remains of late Miocene hominins as soon as 6 Ma in eastern Africa. Bipedality of Sahelanthropus tchadensis was hitherto documented at 7 Ma in central Africa (Chad) by cranial evidence. Here, we present the first postcranial evidence of the locomotor behavior of the Chadian hominin with new insights on bipedalism at the early stage of our evolutionary history. The original material was discovered at locality TM 266 (Toros-Menalla fossiliferous area), and consists in one left femur and two antimeric ulnae. These new findings confirm that hominins were already terrestrial biped relatively soon after the human-chimpanzee divergence but also suggest that careful climbing arboreal behaviors was still a significant part of their locomotor repertoire.
Quaternary International, 2016
International Journal of Water Resources and Environmental Engineering, 2017
This work aimed to contribute to knowledge improvement of the great Lake ecosystems of Chad, prec... more This work aimed to contribute to knowledge improvement of the great Lake ecosystems of Chad, precisely that of the Lakes of Ounianga using bathymetric statements on water levels and the in situ analysis of physicochemical parameters of the lake's waters. Bathymetric surveys facilitated characterization of the morphology of the bottom of the lakes with depths that vary from 0 to-27 m and 0 to-5.7 m for Yoan and Teli Lakes, respectively. With regards to water physio-chemistry, the temperature of the Teli Lake water measuring up to 0.5 m varied from 20.8 to 36°C, while that of Lake Yoan varied from 10.50 to 32.90°C, with an average of 22 and 27°C. The conductivity values oscillated between 69 and 111,700 μS/cm for the Lake Teli and 100 to 64,000 μS/cm for the Lake Yoan. This document illustrates the techniques used in the investigation of a lake whose study constitutes a wide field of continental hydrology.
Journal of African Earth Sciences, 2016
Lake Chad sedimentation and environments during the late Miocene and Pliocene: new evidence from ... more Lake Chad sedimentation and environments during the late Miocene and Pliocene: new evidence from mineralogy and chemistry of the Bol core sediments
Palaeogeography, Palaeoclimatology, Palaeoecology, 2016
cited By 0International audienceno abstrac
Palaeogeography, Palaeoclimatology, Palaeoecology, 2015
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Earth and Planetary Science Letters, 2010
Comptes Rendus Geoscience, 2009
Since the mid 1990s, the Mission paléoanthropologique francotchadienne (MPFT) conducts yearly pal... more Since the mid 1990s, the Mission paléoanthropologique francotchadienne (MPFT) conducts yearly paleontological field investigations of the Miocene-Pliocene of the Chad Basin. This article synthesizes some of the results of the MPFT, with focus on the Chad Basin development during the Neogene. We propose an overview of the depositional paleoenvironments of this part of Africa at different scales of time and space, based on a multidisciplinary approach (sedimentary geology, geomorphology, geophysic, numerical simulations and geochronology). The Miocene-Pliocene paleoenvironments are examined through the sedimentary archives of the early hominids levels and the Holocene Lake Mega-Chad episode illustrates the last major paleoenvironmental change in this area. The sedimentary record of the Chad Basin since the Late Miocene can be schematized as the result of recurrent interactions from lake to desert environments. To cite this article: M.
Revue Française de Photogrammétrie et de Télédétection, 2014
Megalake Chad (350,000 km2), the largest paleo-lake of the Sahara-Sahel area, is one of the most ... more Megalake Chad (350,000 km2), the largest paleo-lake of the Sahara-Sahel area, is one of the most emblematic marker of the hydroclimatic changes that occurred during the African Humid Period (AHP; ca. 11,500 — 5,000 years BP) in subtropical Africa. From field surveys, the existence of Megalake Chad is well demonstrated by widespread typical lake deposits. However, considering the very large size of this paleo-lake, it is best evidenced and understood from space. Conspicuous paleo-littoral features distributed along hundreds of kilometers are clearly visible on second generation satellite images. These features represent major archives of the Megalake Chad and of the climate during the AHP. This paper is the first attempt to investigate the paleo-littoral of Megalake Chad with very high resolution satellite imagery. A Pléiades scene (images and DEM) is used to characterize the fossil sand spit of the Goz Kerki, which is one of the most representative and best preserved littoral featur...
Http Www Theses Fr, 2010
En Afrique et plus particulierement dans le bassin du Tchad, la dynamique des paleoenvironnements... more En Afrique et plus particulierement dans le bassin du Tchad, la dynamique des paleoenvironnements durant le Mio-Pliocene a joue un role crucial dans l’histoire de l’emergence et de l’evolution des hominides anciens. Ce travail tente de reconstituer les environnements de depot du bassin du Tchad pendant les 7 derniers millions d’annees et de faire le lien entre les facies arenitiques de bordures et les facies argileux au centre du bassin. Une attention particuliere est accordee aux environnements et a la dynamique des sites a hominides de la partie Nord du bassin localises dans une zone cle qui a joue un role de tampon oscillant au gre des fluctuations hydroclimatiques. Il tente egalement de retracer l’histoire generale du lac Tchad depuis sa mise en place il y a au moins 7 millions d’annees jusqu’au Quaternaire terminal avec une etude detaillee du dernier colmatage de la plaine alluviale du Chari. Les facies decrits s’echelonnent du lacustre a l’eolien en passant par les facies margino-littoraux deltaiques ou peri-lacustres. Pour la premiere fois, est donne l’âge de l’installation du systeme lacustre du bassin du Tchad. Si la stratigraphie generale du bassin est connue depuis les annees soixante, l’interpretation des facies de ces series sedimentaires n’a jusqu’a present pas fait l’objet d’etudes specifiques notamment en raison de mauvaises conditions d’affleurements et de la difficulte de correler les affleurements entre eux tant en âge qu’en facies. Cette these est une contribution originale a la connaissance de series sedimentaires du bassin du Tchad. Elle apporte de nouvelles donnees pour la comprehension des paleoenvironnements et des paleoclimats du Tchad, du Sahara et de l’Afrique depuis le Miocene terminal jusqu’a l’actuel.
Quaternary Research, 2010
Holocene Lake Mega-Chad (LMC) was the largest late Quaternary water-body in Africa. The developme... more Holocene Lake Mega-Chad (LMC) was the largest late Quaternary water-body in Africa. The development of this giant paleo-lake is related to a northward shift of the isohyetes interpreted as evidence for an enhanced Monsoon (African Humid Period). Numerous preserved coastal features have been described all around the LMC shore. Such features reveal the main paleo-hydrodynamical tendencies. In the context of a closed water-body like LMC, hydrodynamics are forced mainly by winds. We use a three-dimensional numerical model (SYMPHONIE) to simulate the mean hydrodynamics in LMC under both Harmattan-like (northeasterly trade winds) and Monsoon-like (southwesterly winds) forcings. The northern part of LMC displays coastal features, such as sand spits, that are consistent with the simulations forced by Harmattan-like winds. Geomorphic features related to Monsoon-driven hydrodynamics are not clearly expressed. They could have developed during the early stage of LMC but subsequently reworked. A...