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Here we report on Neanderthal engravings on a cave wall at La Roche-Cotard (LRC) in central France, made more than 57±3 thousand years ago. Following human occupation, the cave was completely sealed by cold-period sediments, which prevented access until its discovery in the 19 th century and first excavation in the early 20 th century. The timing of the closure of the cave is based on 50 optically stimulated luminescence ages derived from sediment collected inside and from around the cave. The anthropogenic origin of the spatially-structured, non-figurative marks found within the cave is confirmed using taphonomic, traceological and experimental evidence. Cave closure occurred significantly before the regional arrival of H . sapiens , and all artefacts from within the cave are typical Mousterian lithics; in Western Europe these are uniquely attributed to H . neanderthalensis . We conclude that the LRC engravings are unambiguous examples of Neanderthal abstract design.

International audience; An archaeological site under a rockshelter is not only made up of its archaeological layers; it is also made up of vault and walls that evolve over time and can also be the place for archaeological and environmental recording. Research carried out at the Mandrin Cave (Drôme, France) has led us to study the relationships between these two sedimentary dynamics (on the walls and on the ground), in particular by analysing the disintegration of the walls.In this paper, we will focus on the rate of walls crumbling, how to estimate it and observe its evolution over time, the factors that control it and the palaeo-environmental information that its study can provide. To do this, the "Minimum Number of calcite Doublets" (MND) that formed on the wall before the fall of each clast is used as a proxy to assess the rate of wall disintegration. These data are also compared with the palaeo-environmental information provided by the analysis of the microfauna for each of the archaeological layers. This comparison of data highlights the variable importance of cryoclasticity as a factor of wall desquamation. Above all, it reveals that the association between cold phases and abundance of gelifracts is not necessarily the rule. On the contrary, the processes are much more complex and we show in this article that the number of freeze/thaw cycles, fundamental in the cryoclastic process, is increased in temperate periods.This study, based on field data rather than laboratory experiments, also allows us to characterise the evolution of the rate of wall disintegration and thus the relative importance of freeze-thaw alternations for the different Pleistocene sedimentary units of the Mandrin Cave, with contrasting climatic conditions.; Un site archéologique en grotte ou sous abri ne se résume pas à son remplissage sédimentaire ; il est aussi constitué de parois qui évoluent avec le temps et qui peuvent aussi être le siège d’un enregistrement archéologique et environnemental. Les recherches menées à la Grotte Mandrin (Drôme, France) nous ont conduit à étudier les relations entre ces deux dynamiques sédimentaires (sur les parois, et au sol) notamment via l’analyse du délitement des parois.Dans cette communication, nous nous intéresserons au taux de délitement des parois, à la manière de l’estimer et d’observer ses évolutions au cours du temps, aux facteurs qui le contrôlent et aux informations paléo-environnementales que son étude peut apporter. Pour ce faire, le « Nombre Minimal de Doublets » de calcite (NMD) qui s’est formé sur la paroi avant la chute de chaque claste est utilisé comme proxy pour évaluer le taux de délitement des parois. Ces données sont également mises en regard des informations paléo-environnementales fournies par l’analyse de la microfaune pour chacune des couches archéologiques. Cette confrontation de données permet de mettre en évidence l’importance variable de la cryoclastie comme facteur de desquamation des parois. Surtout, elle révèle que l’association entre phases froides et abondance de gélifracts n’est pas nécessairement la règle. Les processus sont au contraire bien plus complexes et nous montrons dans cet article que le nombre de cycles gel/dégel, fondamental dans le processus de cryoclastie, se retrouve augmentée en périodes tempérées.Cette étude menée à partir de données de terrain, et non à partir d’expérimentations en laboratoire, permet aussi de caractériser l’évolution du taux de délitement des parois et ainsi à l’importance relative des alternances gel/dégel pour les différentes unités sédimentaires pléistocènes de la Grotte Mandrin, aux conditions climatiques contrastées.

International audience; Continental erosion and weathering destroy parts of the stratigraphic record. Analyses of the sedimentary filling of paleokarsts help completing the geological record of regions that have been submitted to post-depositional, long-term, continental evolution. Jurassic carbonate platform of Languedoc (South of France) has undergone several karstification phases from Cretaceous to Neogene. Later incision of canyons through the carbonate massifs allows to observe paleokarsts over 400m depth, within the massifs. Paleokarsts are partly filled with sediments. Some have yielded marine bioclasts (echinoderms, radiolars), foraminifera and nannofossils; others are composed of polygenic detrital sediments, including sources from the upstream Paleozoic basement (Cevennes). The age of the filling of successive paleokarsts can be constrained by structural relationships and by biostratigraphy. These findings suggests 1) the marine elements of the karstic filling relate to a Late Cretaceous to Early Paleocene interval, while 2) the Paleozoic basement-sourced-sediments were trapped in the karst during Miocene to Present. Karstic sediment containing Early Paleocene foraminifera and nannofossils are found in paleokarsts cavities distributed across the entire thickness of the carbonate massif (≥350m). This requires base-level lowering and associated karstification, followed by base-level rise and karst filling of at least 350 m amplitude, respectively. The time interval corresponding to the occurrence of foraminifera and nannofossils in karsts covers 10 Myrs ; surprisingly, no equivalent marine sediments are preserved on the surface. In addition, analyses of the different forams species suggests several (up to 3) distinct karstification and marine filling cycles. Finally, sedimentological facies analysis of the karst filling reveals the following succession of processes: low energy settling of mudstone, high energy reworking, transport and deposition of silts and sandstones within the karst system. Integration of geological, paleontological and sedimentological data, leads to a polyphase scenario in response to repeated base-level variations, more than 350m amplitude. Such an amplitude excludes eustacy, and the improbable repeated sequence of uplift and subsidence rules out tectonics, as driving forces for base-level change, respectively. We propose that the high-amplitude base-level changes results from a succession of desiccation-flooding events of an endorheic, silled, basin during Early Paleogene. The later detrital assemblage sourced in the Cevennes occurs on perched paleosurfaces and in karst cavities across the whole 350m-deep canyon walls. When found on paleosurfaces, they correspond to the south-flowing Early Miocene fluvial drainage, and can be correlated downstream with the marine, well dated, Early Miocene, sediments. When found within the karst cavities, they correspond to successive base-level surfaces connected to the progressive incision of the canyon. This canyon incision is coeval with a Late Miocene uplift of the hinterland.

International audience; no abstract

International audience; The Piei mine-cave (Lagnes, Vaucluse, France) locates at the contact of the Vaucluse Mounts and the Carpentras basin, close to the Fontaine de Vaucluse spring. It develops in Cretaceous limestone (Urgonian facies), close to a main regional lineament, the Salon-Cavaillon fault. The cave was mined in the XIXth Century, giving access to passages previously filled with diverse neogene sands and massive iron crusts. The exploitation mainly followed the natural passages. The origin of the cave is related to hypogenic flow rising from deep fissures or hydraulic breccias, with ferruginous deposition at the contact or on top of the neogene sands filling. Microbial activity was present during the cave activity, associated to the ferruginous deposits. This cave probably corresponds to the Neogene period, when the Vaucluse plateau was uplifted. The Piei mine-cave record the position of the corresponding base level and thus the progressive tilting of the massive, together with a range of similar caves located around the western edge of the Vaucluse Plateau; La grotta di miniera di Piei (Lagnes, Vaucluse, Francia), si trova al contatto tra le montagne della Vaucluse e la piana di Carpentras, vicino alla Fontana di Vaucluse. La grotta si è sviluppata nel calcare Cretaceo (facies Urgoniana) ed è vicina a un'importante faglia regionale. Le attività di estrazione all'interno della grotta cominciarono al principio del XIX secolo, aprendo varchi precedentemente riempiti da sabbie neogeniche e incrostazioni di ferro. Lo sfruttamento seguì principalmente i passaggi naturali. L'origine della grotta è collegata al flusso ipogenico proveniente dalle profonde fenditure o brecce idrauliche che permisero il deposito di ferro nel contatto o in cima alle sabbie neogeniche. L'attività microbica era presente durante il periodo di attività della grotta per via della sedimentazione del ferro. Questa attività probabilmente risale al Miocene, quando il plateau della Vaucluse si sollevò. La grotta registra la posizione del livello di base corrispondente, così come la progressiva inclinazione del massiccio, insieme a una gamma di grotte simili situate intorno all'estremità occidentale del plateau della Vaucluse.

International audience; In this paper, we deal with the cyclic scheduling problem. More precisely, we consider the cyclic job shop with assembly tasks. Such a problem is made of several jobs, each job consisting of tasks (assembly/disassembly tasks and transformation tasks) being assigned to machines in a cyclic way. This kind of scheduling problem is well fitted to medium and large production demands, since the cyclic behavior can avoid the scheduling of the whole tasks by considering only a small temporal window (cycle). Thus, cyclic scheduling is a heuristic to solve the scheduling problems whose complexity is NP-hard in the general case. Many methods have been proposed to solve the cyclic scheduling problem. Among them, we focus on the mathematical programming approach. We will propose here a mathematical model for cyclic scheduling with assembly tasks and Work-In-Process minimization, and we illustrate this approach with an example from literature.