Chronology of human populations in Northwest Africa during the Upper Pleistocene : multi-method chronological approach (ESR/US, OSL et 14C) applied to Rabat-Témara sites

Connue pour ses grottes archéologiques ayant préservé depuis 120 ka des occupations humaines du Middle Stone Age (MSA), Later Stone Age (LSA) et Néolithique, la région de Rabat-Témara constitue un exemple unique en Afrique du Nord pour étudier les questions d’évolution et de dispersion d' H. sapiens . Cette région dispose aussi du plus grand nombre de données géochronologiques en Afrique du Nord-Ouest (215 dates). Cependant, l es chronologies actuelles des occupations humaines à Témara sont sujettes à de nombreux débats. Ce travail de thèse contribue à redéfinir le cadre chronologique des grottes d’El Harhoura 2 et d’El Mnasra par le prisme d’une approche chronologique multi-méthodes comparative des occupations MSA et LSA en lien avec les changements environnementaux. La datation par ESR combinée au sériés de l’uranium (ESR/US) a été appliquée aux dents d’herbivores. La datation par luminescence optiquement stimulée (OSL) a permis de dater des grains de quartz inclus dans le sédiment de ces grottes. Enfin, la datation carbone 14 a été appliquée pour dater des charbons bois. Les 39 datations obtenues dans ce travail, à El Harhoura 2, ont rajeuni la fin du MSA d’environ 15 ka, de dater le LSA, et d’identifier un hiatus chronologique d’environ 30 ka entre la fin du MSA et le LSA, et qui s’étend de la fin du MIS 3 au MIS 2. Pour la grotte d’El Mnasra, les couches d’occupations anciennes du MSA en lien avec une exploitation du littoral pour les ressources marines ont été datées entre 70 et 100 ka, soit environ 10 à 15 ka plus jeunes que les âges précédemment publiés. Les nouvelles données obtenues et la révision des anciennes données chronologiques proposent des pistes méthodologiques encourageantes pour préciser et améliorer le cadre chrono-culturel déjà établi par d’autres méthodes de ces sites de références à l’échelle de l’Afrique du Nord.Known for its archaeological caves that have preserved since 120 ka from human occupations of the Middle Stone Age (MSA), Later Stone Age (LSA) and Neolithic, the Rabat-Témara region is a unique example in North Africa to study the evolution and dispersion of H. sapiens. This region also has the largest amount of geochronological data in Northwest Africa (215 dates). However, the current chronologies of human occupations in Temara are subject to much debate. This thesis work contributes to redefining the chronological framework of the caves of El Harhoura 2 and El Mnasra through the prism of a comparative multi-method chronological approach of the MSA and LSA occupations in relation to environmental changes. ESR dating combined with uranium series (ESR/US) was applied to herbivore teeth. Optically stimulated luminescence (OSL) dating has made it possible to date quartz grains included in the sediment of these caves. Finally, carbon 14 dating was applied to date charcoal. The 39 dates obtained in this work, at El Harhoura 2, rejuvenated the end of the MSA by about 15 ka, dated the LSA, and identified a chronological hiatus of about 30 ka between the end of the MSA and the LSA, and which extends from the end of MIS 3 to MIS 2. For the El Mnasra cave, the layers of ancient MSA occupations related to coastal exploitation of marine resources have been dated between 70 and 100 ka, about 10 to 15 ka younger than previously published ages. The new data obtained and the revision of the old chronological data provide encouraging methodological approaches to refine and improve the chrono-cultural framework already established by other methods for these reference sites across North Africa

Chronologie des peuplements humains en Afrique du Nord-Ouest au Pléistocène supérieur : approche chronologique multi-méthodes (ESR/US, OSL et 14-C) appliquée aux sites de Rabat-Témara

Known for its archaeological caves that have preserved since 120 ka from human occupations of the Middle Stone Age (MSA), Later Stone Age (LSA) and Neolithic, the Rabat-Témara region is a unique example in North Africa to study the evolution and dispersion of H. sapiens. The current chronologies in Temara, human occupations are subject to many debates. This thesis work contributes to redefining the chronological framework of the caves of El Harhoura 2 and El Mnasra through the prism of a multi-method chronological approach (ESR/US, OSL and Radiocarbon 14) of the MSA and LSA occupations in relation to environmental changes. The 39 dates obtained in this work enabled El Harhoura 2 to rejuvenate the end of the MSA by about 15 ka, to date the LSA, and to identity a chronological hiatus of about 30 ka between the end of the MSA and the LSA, and which extends from the end of MIS 3 to MIS 2. For the El Mnasra cave, the layers of ancient MSA occupations related to coastal exploitation of marine resources have been dated between 70 and 100 ka, about 10 to 15 ka younger than the published ages.Connue pour ses grottes archéologiques ayant préservé depuis 120 ka des occupations humaines du Middle Stone Age (MSA), Later Stone Age (LSA) et Néolithique, la région de Rabat-Témara constitue un exemple unique en Afrique du Nord pour étudier les questions d’évolution et de dispersion d’ H. sapiens. Les chronologies actuelles des occupations humaines à Témara sont sujettes à de nombreux débats. Ce travail de thèse contribue à redéfinir le cadre chronologique des grottes d’El Harhoura 2 et d’El Mnasra par le prisme d’une approche chronologique multi-méthodes (ESR/US, OSL et Carbone 14) des occupations MSA et LSA en lien avec les changements environnementaux. Les 39 datations obtenues dans ce travail ont permis, à El Harhoura 2, de rajeunir la fin du MSA d’environ 15 ka, de dater le LSA, et d’identifier un hiatus chronologique d’environ 30 ka entre la fin du MSA et le LSA, et qui s’étend de la fin du MIS 3 au MIS 2. Pour la grotte d’El Mnasra, les couches d’occupations anciennes du MSA en lien avec une exploitation du littoral pour les ressources marines ont été datées entre 70 et 100 ka, soit environ 10 à 15 ka plus jeunes que les âges publiés

The use of paleoclimate simulations to refine the environmental and chronological context of archaeological/paleontological sites

This study illustrates the strong potential of combining paleoenvironmental reconstructions and paleoclimate modeling to refine the paleoenvironmental and chronological context of archaeological and paleontological sites. We focus on the El Harhoura 2 cave (EH2), an archeological site located on the North-Atlantic coast of Morocco that covers a period from the Late Pleistocene to the mid-Holocene. On several stratigraphic layers, inconsistencies are observed between species- and isotope-based inferences used to reconstruct paleoenvironmental conditions. The stratigraphy of EH2 also shows chronological inconsistencies on older layers between age estimated by Optical Stimulated Luminescence (OSL) and Combination of Uranium Series and Electron Spin Resonance methods (combined US-ESR). We performed paleoclimate simulations to infer the global paleoclimate variations over the EH2 sequence in the area, and we conducted a consistency approach between paleoclimate reconstruction estimated from simulations and available from EH2 paleoenvironmental inferences. Our main conclusion show that the climate sequence based on combined US-ESR ages is more consistent with paleoenvironmental inferences than the climate sequence based on OSL ages. We also evidence that isotope-based inferences are more congruent with the paleoclimate sequence than species-based inferences. These results highlight the difference in scale between the information provided by each of these paleoenvironmental proxies. Our approach is transferable to other sites due to the increase number of available paleoclimate simulations

Refinement of the environmental and chronological context of the archeological site El Harhoura 2 (Rabat, Morocco)using paleoclimatic simulations

International audienceThis study illustrates the strong potential of combining paleoenvironmental reconstructions and paleoclimate modeling to refine the paleoenvironmental and chronological context of archeological and paleontological sites. We focus on the El Harhoura 2 cave (EH), an archeological site located on the North Atlantic coast of Morocco that covers a period from the Late Pleistocene to the mid-Holocene. In several stratigraphic layers, inconsistencies are observed between species presence and isotope-based inferences used to reconstruct paleoenvironmental conditions. The stratigraphy of EH also shows chronological inconsistencies in older layers between age estimated by optically stimulated luminescence (OSL) and a combination of uranium series and electron spin resonance methods (combined US–ESR). To infer global paleoclimate variation over the EH sequence in the area, we produced an ensemble of atmosphere-only simulations using the LMDZOR6A model, using boundary conditions and forcings from pre-existing climate simulations performed with the IPSL Earth system climate model to match the different key periods. We conducted a consistency approach between paleoclimatic simulations and paleoenvironmental inferences available from EH. Our main results show that the climate sequence based on combined US–ESR ages is more consistent with paleoenvironmental inferences than the climate sequence based on OSL ages. We also evidence that isotope-based inferences are more consistent with the paleoclimate sequence than species-based inferences. These results highlight the difference in scale between the information provided by each of these paleoenvironmental proxies. Our approach is transferable to other sites due to the increasing number of available paleoclimate simulations

The use of paleoclimate simulations to refine the environmental and chronological context of archaeological/paleontological sites

This study illustrates the strong potential of combining paleoenvironmental reconstructions and paleoclimate modeling to refine the paleoenvironmental and chronological context of archaeological and paleontological sites. We focus on the El Harhoura 2 cave (EH2), an archeological site located on the North-Atlantic coast of Morocco that covers a period from the Late Pleistocene to the mid-Holocene. On several stratigraphic layers, inconsistencies are observed between species- and isotope-based inferences used to reconstruct paleoenvironmental conditions. The stratigraphy of EH2 also shows chronological inconsistencies on older layers between age estimated by Optical Stimulated Luminescence (OSL) and Combination of Uranium Series and Electron Spin Resonance methods (combined US-ESR). We performed paleoclimate simulations to infer the global paleoclimate variations over the EH2 sequence in the area, and we conducted a consistency approach between paleoclimate reconstruction estimated from simulations and available from EH2 paleoenvironmental inferences. Our main conclusion show that the climate sequence based on combined US-ESR ages is more consistent with paleoenvironmental inferences than the climate sequence based on OSL ages. We also evidence that isotope-based inferences are more congruent with the paleoclimate sequence than species-based inferences. These results highlight the difference in scale between the information provided by each of these paleoenvironmental proxies. Our approach is transferable to other sites due to the increase number of available paleoclimate simulations

The use of paleoclimate simulations to refine the environmental and chronological context of archaeological/paleontological sites

This study illustrates the strong potential of combining paleoenvironmental reconstructions and paleoclimate modeling to refine the paleoenvironmental and chronological context of archaeological and paleontological sites. We focus on the El Harhoura 2 cave (EH2), an archeological site located on the North-Atlantic coast of Morocco that covers a period from the Late Pleistocene to the mid-Holocene. On several stratigraphic layers, inconsistencies are observed between species- and isotope-based inferences used to reconstruct paleoenvironmental conditions. The stratigraphy of EH2 also shows chronological inconsistencies on older layers between age estimated by Optical Stimulated Luminescence (OSL) and Combination of Uranium Series and Electron Spin Resonance methods (combined US-ESR). We performed paleoclimate simulations to infer the global paleoclimate variations over the EH2 sequence in the area, and we conducted a consistency approach between paleoclimate reconstruction estimated from simulations and available from EH2 paleoenvironmental inferences. Our main conclusion show that the climate sequence based on combined US-ESR ages is more consistent with paleoenvironmental inferences than the climate sequence based on OSL ages. We also evidence that isotope-based inferences are more congruent with the paleoclimate sequence than species-based inferences. These results highlight the difference in scale between the information provided by each of these paleoenvironmental proxies. Our approach is transferable to other sites due to the increase number of available paleoclimate simulations

: New key data for defining the cultural and chronological framework of the Middle Stone Age occupations at El Mnasra cave, Morocco

International audienceOver the last 20 years, there has been a growing interest in studying coastal North African Middle Stone Age (MSA) sites for their implication in understanding the development/expansion of Homo sapiens. One of them is El Mnasra cave (Rabat-Temara region), a rare example in North Africa of coastal caves with well-preserved MSA occupations presenting a great interest in studying livelihood strategies adopted by North African Middle Stone Age humans in coastal areas with the production of symbolic and cognitive hallmarks. Here, we present a series of new data published in the last two years,and their clear implications for the human occupations of the site. First, we updated the chronostratigraphic model for the MSA archaeo-sequence of El Mnasra cave and confirmed a human presence between 124–104 ka, earlier than showed by the previous OSL and US-ESR data. We considerably extended the age of the MSA occupations to the MIS 4/3 (~62–30 ka). El Mnasra cave yielded the largest record of Nassariidae perforated shells, and we evidenced that their use by the Aterian groups at El Mnasra dates from the MIS 5d-5b (~115–94 ka) to the MIS 4/3 (~62–30 ka).Second, this new chronological framework allows recontextualizing an important discovery about plant management: we reported the presence in El Mnasra cave of the earliest use of fruits and wood from olive trees in Africa, dated around 100 ka. These findings suggest the presence of olive trees on the Atlantic coast of Morocco during most of the last glacial period and the use of olives by the early Homo sapiens for fuel management and, most probably, for consumption

Nouvelles données clés pour définir le cadre culturel et chronologique des occupations Middle Stone Age de la grotte d'El Mnasra, Maroc

International audienceOver the last 20 years, there has been a growing interest in studying coastal North African Middle Stone Age (MSA) sites for their implication in understanding the development/expansion of Homo sapiens. One of them is El Mnasra cave (Rabat-Temara region), a rare example in North Africa of coastal caves with well-preserved MSA occupations presenting a great interest in studying livelihood strategies adopted by North African Middle Stone Age humans in coastal areas with the production of symbolic and cognitive hallmarks. Here, we present a series of new data published in the last two years,and their clear implications for the human occupations of the site. First, we updated the chronostratigraphic model for the MSA archaeo-sequence of El Mnasra cave and confirmed a human presence between 124–104 ka, earlier than showed by the previous OSL and US-ESR data. We considerably extended the age of the MSA occupations to the MIS 4/3 (~62–30 ka). El Mnasra cave yielded the largest record of Nassariidae perforated shells, and we evidenced that their use by the Aterian groups at El Mnasra dates from the MIS 5d-5b (~115–94 ka) to the MIS 4/3 (~62–30 ka).Second, this new chronological framework allows recontextualizing an important discovery about plant management: we reported the presence in El Mnasra cave of the earliest use of fruits and wood from olive trees in Africa, dated around 100 ka. These findings suggest the presence of olive trees on the Atlantic coast of Morocco during most of the last glacial period and the use of olives by the early Homo sapiens for fuel management and, most probably, for consumption

: New key data for defining the cultural and chronological framework of the Middle Stone Age occupations at El Mnasra cave, Morocco

International audienceOver the last 20 years, there has been a growing interest in studying coastal North African Middle Stone Age (MSA) sites for their implication in understanding the development/expansion of Homo sapiens. One of them is El Mnasra cave (Rabat-Temara region), a rare example in North Africa of coastal caves with well-preserved MSA occupations presenting a great interest in studying livelihood strategies adopted by North African Middle Stone Age humans in coastal areas with the production of symbolic and cognitive hallmarks. Here, we present a series of new data published in the last two years,and their clear implications for the human occupations of the site. First, we updated the chronostratigraphic model for the MSA archaeo-sequence of El Mnasra cave and confirmed a human presence between 124–104 ka, earlier than showed by the previous OSL and US-ESR data. We considerably extended the age of the MSA occupations to the MIS 4/3 (~62–30 ka). El Mnasra cave yielded the largest record of Nassariidae perforated shells, and we evidenced that their use by the Aterian groups at El Mnasra dates from the MIS 5d-5b (~115–94 ka) to the MIS 4/3 (~62–30 ka).Second, this new chronological framework allows recontextualizing an important discovery about plant management: we reported the presence in El Mnasra cave of the earliest use of fruits and wood from olive trees in Africa, dated around 100 ka. These findings suggest the presence of olive trees on the Atlantic coast of Morocco during most of the last glacial period and the use of olives by the early Homo sapiens for fuel management and, most probably, for consumption

Archaeological sites and palaeoenvironments of Pleistocene West Africa

African paleoanthropological studies typically focus on regions of the continent such as Eastern, Southern and Northern Africa, which hold the highest density of Pleistocene archaeological sites. Nevertheless, lesser known areas such as West Africa also feature a high number of sites. Here, we present a high-resolution map synthesising all well contextualised Pleistocene archaeological sites present in Sub-Saharan West Africa. A detailed elevation and ecoregional map was developed and correlated with palaeoanthropological sites. This map is supplemented with 1,000- and 2000-year interval climate reconstructions over the last 120,000 years for three subregions of high archaeological interest. The presented archaeological sites were compiled by reviewing published literature, and selected based on: (1) documented archaeological stratification or >10 characteristic artefacts, (2) published coordinates, and (3) published chronometric ages or relative dating. The data presented here elucidates the current state of knowledge of Pleistocene West Africa, highlighting the regional potential for human evolutionary studies