In global geodynamics, one of the most striking events is the transition from continental rifting to oceanic spreading, as most of the involved parameters fundamentally change (rift to drift, mantle source of magmas, nature of the lithosphere, magmatic plumbing system architecture, hydrothermal system). Despite their importance for the Earth geodynamics, the processes that govern the initiation of oceanic spreading and the associated production of juvenile magmatic crust remain first order open questions for the international geo-community. Few quantitative constraints exist on how magmatic spreading initiates to form steady MOR? In other words: How and when typical magmato/tectonic processes of oceanic spreading are gradually emplaced during Ocean Continent Transition (OCT) stage? Ultimately, why, at a certain moment, continental thinning switch to magmatic accretion and initiates the break-up? These fundamental questions could be tackled either by models (numerical or analogic) or following quantitative documentation of processes on fossil OCT and/or on active mature rifts, that can be viewed as nascent MOR. The Afar region at the northern end of the East African Rift system is the unique place on Earth where magmatic continental rifting and associated ongoing break-up processes are exposed onshore. This magmatic rift system is dissecting a Large Igneous Province and is connected laterally to the Red Sea and Gulf of Aden oceanic spreading ridges. This system presents the key advantage to expose extensional structures considered at ocean-continent transition with magmatic segments characterized by contrasted morphologies, magmato-tectonic styles, and maturity that have tentatively been assimilated to proto-spreading centers. The main working hypothesis of this project is that Afar is presently experiencing the final stage of continental break-up and progressive onset of steady magmatic spreading (process already completed in the lateral Red Sea and Gulf of Aden). The three main active, contrasted and complementary magmatic segments of Afar (Erta Ale, Dabbahu-Manda Hararo, Assal) offer the opportunity to study mantle and crustal processes in order to decipher fundamental parameters that control focussing of tectonic and magmatic activity until complete removal of continental lithosphere. The MAGMAFAR project is designed to make a breakthrough into this key and first order fundamental scientific issue of continental break-up in magmatic context, and rift transition to the onset of MOR. We will particularly focus on: (i) how do magmatic and tectonic processes control the styles and morphologies of magmatic segments? what are the parameters responsible for the characteristics of proto, steady-state spreading processes? (ii) why and how stable magma production and organized/focussed transfer to the crust start and led to break-up? Along the active magmatic segments of Afar we still need to understand precisely: how magmas are generated? how they are transferred to the crust? how they interact and are controlled by other forcing parameters (in particular, the mechanical behavior of the lithosphere)? We elaborated a general strategy that will combine high resolution quantification of both tectonic and igneous processes in the (i) active and (ii) plio-quaternary natural systems, which will serve in turn to calibrate (iii) an integrated thermo-mechanical modelling. Such an integrated and multidisciplinary approach, based on the combination of numerous complementary skills (petrology / geochemistry / geochronology / remote-sensing / structural geology / thermomechanical modelling), will be focused on the comprehensive description of these unique active segments, in order to bridge timescales and processes across the entire Afar Rift System. The MAGMAFAR project will produce a significant number of deliverables that will gradually cover the description and understanding of magmatic OCT from individual processes to general models.

We propose to characterize the response of continental biosphere to large extraterrestrial impact craters, in particular the megafires they may have generated, associated with the melting of the Earth surface. Studying the impact glasses ejected at long distance, called tektite, will be instrumental in the project. Three tektite producing impacts occurring on forested tropical surfaces from Nicaragua, Ghana, and Indochina during the last 1.1 Myr will be investigated. Environmental response to impact, probed by pollen, charcoal and other proxies will be studied in various marine and lacustrine archives. Reaction of impact melt with biomass (elements such as C, P, S) will be traced using compositional variability of tektites explored in a systematic way, as well as nano-scale characterization of inclusions in tektites such as phosphates, metal, iron oxydes, and eventual carbon phases. This will bring new clues on tektite production processes and response of ecosystems to megafires.

Climate change, declining sediment supply, and global population growth in the coastal zone are projected to result in unprecedented socio-economic losses and environmental changes in the coming decades. Coastal management and planning require improved understanding of past and future shoreline evolution and its drivers. However, both observations and models have provided inconsistent or fragmented insight so far. The major cross-discipline advances in the modelling and remote sensing of large-scale (O(1-100 km)) and long-term (O(10 years)) shoreline change, together with the potential of data assimilation to optimally combine satellite imagery and shoreline modelling, calls for an ambitious and innovative research project. In SHORMOSAT we will both improve a state-of-the-art hybrid shoreline model (LX-Shore) and apply well-adapted data-assimilation techniques using more than 35 years of satellite-derived shoreline data. We will further address shoreline change and the primary drivers and processes and their interactions, and will explore the future of beaches where accommodation space is limited by e.g. coastal structures. We will apply this new framework to seven carefully selected national and international field sites distributed across three continents, representing the most widespread sandy coast environments and where a wealth of field data are collected by our consortium and international collaborators: (i) coastal embayments (O(1 km)) with various degrees of headland/groyne sand bypassing and wave exposure, (ii) wave-dominated deltas (O(10-100 km)), (iii) long sandy barriers (O(100 km)) interrupted by tidal inlets and estuary mouths. Improvements to LX-Shore and extension of its scope of application will be achieved by including obstacle sand bypassing, sediment source, a beach profile change module and a new wave module. Approximately 35 years of time series of satellite-derived waterline, shoreline position and associated errors will be generated at our seven study sites by developing and applying advanced image analysis technics. LX-Shore will be calibrated on our study sites based on a non-linear optimisation method and we will further develop a new data-assimilation framework in LX-Shore using satellite-derived shorelines. These developments will allow addressing the dominant spatial and temporal modes of shoreline variability and identifying the respective contributions of the different drivers and links between model parameter variability and wave forcing variability for the different coastal environments over the past ~35 years. Such an assessment will guide the preferred model configurations to address future shoreline change. Building on Intergovernmental Panel on Climate Change (IPCC) wave and sea-level-rise projections, future shoreline change will be estimated up to 2100 using ensemble simulations, together with the uncertainties related mainly to sea-level rise and model parameters. We will address if, where, when and why critical changes may occur (e.g., potential demise of beaches where accommodation space is limited). Overall, SHORMOSAT will provide fresh insight into past and future multi-decadal shoreline change and trajectory shifts in a context of climate change and increasing anthropogenic pressure, with important overarching implications for society and coastal planning.

In the actual global change context, one of our issues is to constrain geological processes in relation with forcings, including dynamics of climat change, that condition environment and resources of the critical zone. In such a context, alluvial systems constitute very suitable proxies. Indeed, alluvial sediments provide valuable information about the conditions that prevailed at the time of their deposition. They constitute the response of an aggrading system to the climatic, tectonic (paleo)geographic and anthropic contexts of the last millennia. The characterization of sediments in an alluvial system, in particular their source, but also the sedimentary dynamics they reflect, allows to indirectly evaluate these constraints. Within these sediments, quartz has the advantage of being extremely ubiquitous. It is found in a large majority of alluvial systems, is very resistant and slightly affected by alteration, either over time or between upstream and downstream transfer systems, or even during different sedimentary cycles. Finally, quartz is characterized by a composition and a behaviour in front of various stimuli (light, irradiation, ...) which seems related to the initial conditions of formation, but perhaps also to its sedimentary history. In QUARTZ project, we aim to develop a new methodology of characterization for quartz grains, by using their luminescence and paramagnetic properties together with their composition and repartition in trace elements to use them as markers of sedimentary dynamics. Our approach is based on the unique and innovative combination of reliable characterization and dating methods, such as Optically Stimulated Luminescence (OSL), Electron Spin Resonance (ESR), Cathodoluminescence (CL) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) but also participate in the development of innovative technologies such as Laser Induced Breakdown Spectroscopy (LIBS) in order to achieve a high level of quartz characterization. QUARTZ project intend to demonstrate that each quartz grain has a specific signature of its origin and to determine how this signature evolves over time, along the various sediment recycling. Understanding the variations of quartz grain characteristics within the rivers sediment will help to estimate the variation over time of the alluvial dynamics, including volumes of sediments transported in a Source-to-Sink point of view and indirectly response of the system to external changes.

Women are central in the neolithisation process. The ways they are involved in the societies are determined by social organizations and local patterns according to the environment and the subsistence economy. The WomenSOFar project aims at documenting how females eat, move, care for and work among the early agropastoralists societies of the Neolithic (6th-4th mill. BC) in different ecological areas in France and the Mediterranean area. It proposes a unique multi-disciplinary approach combining environmental, biochemical, cultural and biological data obtained on human remains. The project expects to test the hypotheses of females vs. males’ dietary diversity and mobility; it also expects to highlight specific weaning strategies, potential early life mobility and to correlate health and activities to the biogeochemical markers. The project aims at contributing to our understanding on the origin of our modern life societies and the diversity of females vs. males’ social burdens.