Nanocrystalline oxides are ubiquitous in the environment. Their minute size leads to a large surface to volume ratio, and thus to a large density of reactive border sites. Reactivity is reinforced when these oxides are lamellar, meaning that they are built of layers of atoms separated by an interlayer space. Vernadite and fougèrite belong to this family of minerals. Both have layer built of octahedra connected through their edges. In vernadite, these octahedra have for nominal formula (Mn4+O6)8-, whereas in fougèrite these are (Fe2+O6)10- and (Fe3+O6)9-. Both minerals are of prime interest to the understanding of ion, nutriments, water and organic pollutants fate in the environment. For example, vernadite controls the fate of trace metals in seafloors, sediments, preserved and polluted soils, and fougèrite controls the cycle of (oxy-)anions in gleysols. Additionally, both minerals are capable of degrading organics and organic pollutants. Such reactivity comes from their layer structure: like clays, these oxides have two main layer crystallization defects: isomorphic layer substitution (i.e. substitution of a layer ion by another of similar or different valence) and layer vacancies (i.e. a layer ion is missing). This results in a modification of layer charge which is compensated for by hydrated interlayer ions. In vernadite layer charge is negative, and the interlayer contains cations, whereas in fougèrite, layer charge is positive and the interlayer contains anions. These two types of defects induce very contrasted chemical reactivity: isomorphic substitution creates a limited layer charge (typically one electron per layer octahedron) and is compensated for by interlayer ions adsorbed as hydrated outer-sphere complexes (e.g. sodium or calcium in vernadite) whereas vacancies create a strong local layer charge (equal to the charge of the missing ion) which may be compensated for by ions adsorbed as inner-sphere complexes above vacancies (e.g. in vernadite, transition metals). Because the abundance of both defects is variable, it is obvious that a mineral name (“vernadite” or “fougèrite”) hides a wide variety of crystal structures and thus of reactivity. Understanding and thus being able to predict the latter requires a sound understanding of the former. Unfortunately, classical structural refinement methods based on modeling of X-ray diffraction patterns are impaired by the extreme structural disorder reigning in theses phases and in particular from two types of layer stacking defects: turbostratism (systematic occurrence, between adjacent layers, of random translation about the normal to the layers and/or of random translation in the layer plane) and interstratification (stacking of at least to types of unit-cells of contrasting structure). To circumvent this problem, a specific mathematical formalism will be used to determine the crystal structure of series of samples from a given mineral (vernadite or fougèrite) but having contrasted nature and density of structural defects (layer vacancies or isomorphic substitutions) that will induce different reactivity towards ions. This latter will be elucidated by performing sorption isotherms of the elements of interest and simulating them with surface complexation models. The structural information retrieved from analysis of X-ray diffraction patterns will be complemented by transmission electron microscopy, molecular simulation in the Grand Monte Carlo Ensemble and methods taking advantage of spectrocopic methods and probing the local order. In particular, EXAFS will be used to probe the local environment around the sorbed ion, and pair distribution function will probe the relative changes between samples having same initial layer structure but loaded with different amounts of the ion of interest. By collating information obtained from surface complexation modeling and from structural analysis methods, a link between structure and reactivity will be obtained.

Rare metals (e.g. Li, Ta, Sn) are critical components for the renewable energy technologies. In Europe, a significant part of the resources issues from rare-metal granites and pegmatites (RMPG), especially those known in the Variscan belt remnants, such as the French Massif Central (FMC) and Iberian Massif. In order to achieve the green high-technology revolution, a sustainable European supply of Li and Ta needs the exploitation of the European RMPG deposits. However, the economic, environmental and societal impacts of such exploitation must be clarified. Furthermore, the geological processes involved in the genesis of such peculiar magmatic rocks and their extreme metal enrichment, e.g. the metallogenic model, remain poorly understood. This makes difficult the prediction of favourable areas for new discoveries. The TRANSFAIR project is a stimulating consortium that gathers a transdisciplinary expertise from geosciences to human sciences. It will provide a comprehensive metallogenic model for RMPG, enhancing district to deposit-scale mineral prospectivity mapping. To reach these objectives, TRANSFAIR will rely on two typical examples known in the FMC and Iberia, common learning fields for all the project activities. Based on recent results, TRANSFAIR propose to study the hypothesis of the RMPG origin from partial melting of Li-rich sedimentary source(s), combining innovative melting experiments and the characterization of natural objects following several approaches (petrology, geochemistry and geochronology). Ascent and emplacement processes, key parameters to explain the locations of the deposits, will be better constrained thanks to a coupled work of experimental petrology and numerical modelling. These results will be compared to natural case studies by a 3D understanding of the tectonic and structural contexts of ascent and emplacement of the deposits, reached by the acquisition of new geophysical and field data. Geochemistry (including stable and radiogenic isotope systematics) and geochronology will draw a better knowledge of the magmatic history of RMPG fields, from partial melting to emplacement of barren rocks and ore deposits. The integration of all these results will build predictive maps of favourable areas for RMPG. In the context of a significant increase of the needs for Li, which will lead to a strong increase of mining activities. TRANSFAIR will also draw the sociologic, economic benefits and disadvantages of new operations of RMPG in Europe and the strategy for societal engagement for renewed mining activities in Europe. Thus, TRANSFAIR will decipher the economic parameters linked to the valorisation of European RMPG by an econometric approach. Based on life cycle analysis, environmental impacts of these domestic operations will be compared to the actual global market. At last, levels of potential acceptability of mining projects in France, Portugal and Spain will be evaluated determining the concerned territories profiles, mapping stakeholders and adapting the social risk index. Simultaneously, TRANSFAIR will assess imaginaries linked to lithium, actually essential for the energy transition, making the link with the cartography of the geological potential issued from the project. As an answer to the actual needs of critical metals, TRANSFAIR will bring solutions towards better knowledge and valorisation of the European potential of RMPG, giving the keys both for a more efficient exploration, but also the bases for a better understanding between all stakeholders (citizens, public institutions and industries).

Europe cities and their hinterlands are major foci of business, heritage, culture and development. Many have geological issues that inhibit economic and sustainable development. Moreover, underneath today's city streets exists a labyrinth of caves, quarries and lifelines (sewer, gas, electric and telecommunication lines). The knowledge about the location of these buried infrastructures represents crucial information for a continuous utility management, including quick response to emergencies, efficient repair working and planned extensions of existing networks. The 3D visualisation of all buried utilities as well as geoscientific information is technically feasible. However, an application integrating and visualising the subsoil components into a city model (i.e. buried networks and geoscientific information like geological models, drill-holes, hydrogeological models ...) does not yet exist. Such tools may prove to be very useful in the management of underground related issues (e.g. maintenance of networks, underground water levels, mechanical properties of soils, presence of cavities, etc), which is at the moment less intuitive due to the lack of underground information in City Models. DeepCity3D project intends to develop application-adaptive 3D visualisation tools that integrate for the first time underground data and City models (provided in standardised formats) with advanced functionalities to support decision making in Urban Planning, Construction Companies, Insurance Companies, Architects, Environmental Protection.

Groundwater is a strategic resource for modern economies worldwide; yet it is over-exploited at an alarming rate. New forms of governance are sought, in particular in rural areas with intensive agricultural irrigation where authorities lack the means to regulate large numbers of dispersed users. During the Fellowship, I will develop new understanding of strategies and institutional arrangements for increasing the resilience of groundwater dependent rural economies, and develop and test a methodology that support local actors to design collective solutions. Overall, the Fellowship aims to: (1) carry out a global assessment of strategies and institutions currently used worldwide; (2) develop a participatory foresight methodology to support the design of innovative strategies and institutional arrangements in two case studies; and (3) promote academic exchange and disseminate research. The Fellowship will enable me to strengthen my empirical and theoretical knowledge of the design of institutions for common-pool resource management and natural resource management, and position me as a leading scholar in the competitive research community on environmental and institutional economics. A carefully crafted series of scientific exchanges and collaborations will expand my outreach to a global level, and open opportunities for new research collaborations. The French Geological Survey (BRGM), France, is the ideal host organisation to carry out this research because of its established expertise on groundwater management with an emphasis on inter-disciplinary research of high societal relevance, and its extensive global networks. I will contribute to BRGM’s current research agenda and strengthen its collaborations in and outside Europe. My research will contribute to Europe’s knowledge base economy by providing new insights to safeguard society against water-related vulnerabilities.