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The multidisciplinary DIGISOIL consortium intends to integrate and improve in situ proximal measurement technologies for assessing soil properties and soil degradation indicators, moving from the sensing technologies themselves to their integration and application in (digital) soil mapping (DSM). The core objective of the project is to explore and exploit new capabilities of advanced geophysical technologies for answering this societal demand. To this aim, DIGISOIL addresses four issues covering technological, soil science, and economic aspects: (i) development and validation of hydrogeophysical technologies and integrated pedo-geophysical inversion techniques; (ii) the relation between geophysical parameters and soil properties; (iii) the integration of derived soil properties for mapping soil functions and soil threats; and (iv) the evaluation, standardisation, and industrialisation of the proposed methodologies, including technical and economic studies.

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International audience, One of the main features of 'post mining' research relates to available methods for monitoring mine-degradation processes that could directly threaten surface infrastructures. In this respect GISOS, a French scientific interest group is investigating techniques for monitoring the eventual collapse of underground cavities. One of methods under investigation was monitoring the stability of a salt cavity through recording microseismic-precursor signals that may indicate the onset of rock failure. The data were recorded in a salt mine in Lorraine (France) when monitoring the controlled collapse of 2,000,000 m3 of rocks surrounding a cavity at 130 m depth. The monitoring in the 30 Hz to 3 kHz frequency range highlights the occurrence of events with high energy during periods of macroscopic movement, once the layers had ruptured; they appear to be the consequence of the post-rupture rock movements related to the intense deformation of the cavity roof. Moreover the analysis shows the presence of some interesting precursory signals before the cavity collapsed. They occur a few hours before the failure phases, when the rocks were being weakened and damaged. They come from the damaging and breaking process, when micro-cracks appear and then coalesce. From these results we expect that deeper signal analysis and statistical analysis on the complete event time distribution (several millions of files) will allow us to finalize a complete typology of each signal families and their relations with the evolution steps of the cavity over the five years monitoring.

Nuclear waste repositories are being installed in deep excavated rock formations in some places in Europe to isolate and store radioactive waste. In France, the Callovo-Oxfordian formation (COx) is a potential candidate for a nuclear waste repository. The redox reactivity (kinetics and thermodynamic redox potential) of COx clay rock samples are already under study using microscopic, spectrometric and wet analysis techniques. In order to cross and overcome certain limits by improvement in the knowledge, specific electrodes should be constructed and devoted to the deepening of the electrochemical behaviour of the COx system in different situations. Iron is one of the most common redox species in soils and sedimentary rocks. Iron-bearing phyllosilicates play key roles in various biogeochemical processes. The complexity of the physical and chemical (along with structural) changes involving their structural iron makes the studies of its redox properties challenging. Most of the recent reported efforts were focused on probing Fe redox on finely powdered clay (and often micas) particles, and have been hampered by inadequate interactions between particles and electrodes. Moreover, such experiments usually involve redox probe ions, thus adding supplementary difficulties in the determination of structural iron redox parameters such as redox potential (Eh) and kinetics. The present study aims at qualitatively investigating the above mentioned phenomena on minerals like iron-bearing micas. In the current work, we present initial insights regarding efforts to build a direct electrical interface between solid electrodes and conveniently shaped macroscopic mica crystals in order to investigate the redox properties of structural iron in dry and aqueous environments, in the presence of representative perturbations. A classical three electrode system has been used for voltammetric measurements. Platinum plate (1cm²) was the counter electrode. Potentials have been measured against eit

Iron is one of the most common redox species in soils and sedimentary rocks. Amongst iron-bearing phases, phyllosilicates might play key roles in various bio-geochemical processes involving redox reactions, where structural Fe (Festr) can act as a renewable source/trap of electron. A large set of data from kinetics, spectroscopic or electrochemical studies on dioctahedral smectites demonstrates that reduction of Festr impacts many clay properties such as colour, layer charge, swelling pressure, colloidal properties that are linked to layer structural changes. Experiments also suggest that this mechanism is partly reversible, depending on type and properties of the primary oxidized clay, on how the reduction is induced (chemically and/or biologically) and on extent of iron reduction level. The complexity of the involved mechanisms makes the prediction of Festr redox properties challenging. For instance, only empirical models are currently available to quantify structural changes as a function of reduction level. However, a predictive and mechanistic model of these changes is a prerequisite to develop a thermodynamic model for Festr redox properties. In this contribution, we propose a mechanistic statistical model to explain 2:1 layer excess negative charge changes induced by structural Fe(III) to Fe(II) chemical reduction (by dithionite). This model completes this published by Drits and Manceau (2000) and was calibrated on data from our own and from the literature. Actually, a large number of studies on Festr redox properties (Eh and kinetics) neglects the major structural changes that occur during redox reactions of this material and that are partially reversible, and are focused in measuring a single Eh value. Actually, the complex relationship that exist between the different structural iron sites should lead to consider that not only one but several Fe(II)/Fe(III) poles (classes) must exist in the structure, thus exhibiting gradually decreasing Eh values. Hence

National audience, Nous avons régionalisé 12 scénarios de changement climatique d'origine anthropique dans le bassin de la Seine, pour servir en entrée de 5 modèles hydrologiques différents. Les scénarios hydrologiques résultants s'accordent tous sur un assèchement prononcé des bassins étudiés d'ici à la fin du 21ème siècle, avec une baisse des nappes et des débits en moyenne annuelle. A l'échelle saisonnière, la baisse des débits se répercute davantage sur les basses eaux que sur les hautes eaux, dont la baisse est moins robuste. La réponse des valeurs extrêmes est plus contrastée, et les crues extrêmes, identifiées par les quantiles décennaux QJXA10, ne changeraient pas significativement au cours du 21ème siècle. Nos résultats suggèrent aussi que la crue centennale, extrapolée selon la méthode du gradex, resterait du même ordre de grandeur qu'actuellement.

National audience

International audience, The active acid gas (H2S-CO2 mixture) injection operations in Nortn America provide practical experience for the operators in charge of industrial scale CO2 geological storage sites. Potential leakage via wells and their environmental impacts make well construction durability an issue for efficiency/safety of gas geological storage. In such operations, the well cement is in contact with reservoir brines and the injected gas, meaning that gas-water-solid chemical reactions may change the physical properties of the cement ans its ability to confine the gas downhole. The cement-forming Calicum silicate hydrates carbonation (by CO2) and feriite sulfidation (by H2S) reactions are expected. The main objective of this study is to determine their consequences on cement mineralogy and trasfert ability. 15 and 60 days duration batch experiments were performed, as welle as numerical simulation of the experiments. The work suggest that in both acid gas and CO2 geological storage, clogging of cement or at least mineral assemblage conservation and slowing of carbonation progress could occur in near-well zones where slight water flow occurs e.g. in the vicinity of caprock shales.

Chapters are included on the distribution of stresses, rock breakage, general tectonics, definitions and descriptions of various types of fracture, fracture mechanics, relationships between various types of fractures, modes of fracturing, relationships between large and small scale fractures, and relationships of fractures to folds., Chapters are included on the distribution of stresses, rock breakage, general tectonics, definitions and descriptions of various types of fracture, fracture mechanics, relationships between various types of fractures, modes of fracturing, relationships between large and small scale fractures, and relationships of fractures to folds.

Chapters are included on the preparation and organisation of a mineral prospecting expedition in intertropical belts, prospecting by drilling, prospecting of alluvial, eluvial and coastal deposits, geochemical prospecting, geophysical prospecting, boring in mineral prospecting, and prospecting in working mines., Chapters are included on the preparation and organisation of a mineral prospecting expedition in intertropical belts, prospecting by drilling, prospecting of alluvial, eluvial and coastal deposits, geochemical prospecting, geophysical prospecting, boring in mineral prospecting, and prospecting in working mines.

Contents include sections on economic and legal aspects of seabed mining; marine aggregates: exploration, mining and commercialisation; placers: recent prospecting and industrial possibilities; continental shelf dredging; future prospects; metalliferous muds and development, example from the Red Sea; polymetallic nodules: recent advances in exploration; discussion forum: have polymetallic nodules an economic future?; future techniques in deep sea mining., Contents include sections on economic and legal aspects of seabed mining; marine aggregates: exploration, mining and commercialisation; placers: recent prospecting and industrial possibilities; continental shelf dredging; future prospects; metalliferous muds and development, example from the Red Sea; polymetallic nodules: recent advances in exploration; discussion forum: have polymetallic nodules an economic future?; future techniques in deep sea mining.

The sheet covers eastern Turkey, Cyprus, Syria, Lebanon, Israel, Jordan, Iraq, western Iran, and parts of the Crimea, Egypt, and Saudi Arabia. Metallogenic provinces and specific deposits are indicated with their general geological context, age, morphology, nature of the mineral, principal metals, genetic type, and nature of the deposit, all depicted by means of colour coding or symbols. The accompanying mineral deposits lists are arranged in three sequences: geographical (in order of latitude within each country), alphabetical (by deposit name within each country), and by commodity., The sheet covers eastern Turkey, Cyprus, Syria, Lebanon, Israel, Jordan, Iraq, western Iran, and parts of the Crimea, Egypt, and Saudi Arabia. Metallogenic provinces and specific deposits are indicated with their general geological context, age, morphology, nature of the mineral, principal metals, genetic type, and nature of the deposit, all depicted by means of colour coding or symbols. The accompanying mineral deposits lists are arranged in three sequences: geographical (in order of latitude within each country), alphabetical (by deposit name within each country), and by commodity.

The sheet covers Denmark, West Germany, East Germany, Switzerland, Austria, Poland, Czechoslovakia, Hungary, Rumania, and parts of the USSR, Sweden, northeast France, Benelux, north Italy, and Yugoslavia. Metallogenic provinces and specific deposits are indicated, with their general geological context, age, morphology, nature of the mineral, principal metals, genetic type, and nature of the deposit, all depicted by means of colour coding or symbols. The accompanying mineral deposits lists are arranged in three sequences: geographical (in order of latitude within each country), alphabetical (by deposit name within each country), and by commodity., The sheet covers Denmark, West Germany, East Germany, Switzerland, Austria, Poland, Czechoslovakia, Hungary, Rumania, and parts of the USSR, Sweden, northeast France, Benelux, north Italy, and Yugoslavia. Metallogenic provinces and specific deposits are indicated, with their general geological context, age, morphology, nature of the mineral, principal metals, genetic type, and nature of the deposit, all depicted by means of colour coding or symbols. The accompanying mineral deposits lists are arranged in three sequences: geographical (in order of latitude within each country), alphabetical (by deposit name within each country), and by commodity.

The sheet covers Corsica, Sardinia, southern Italy and Sicily, southern Yugoslavia, Albania, Greece, Bulgaria, western Turkey, and the north African coast from Alexandria to Tunisia. Metallogenic provinces and specific deposits are indicated, with their general geological context, age, morphology, nature of the mineral, principal metals, genetic type, and nature of the deposit, all depicted by means of colour coding or symbols. The accompanying mineral deposits lists are arranged in three sequences: geographical (in order of latitude within each country), alphabetical (by deposit name within each country), and by commodity., The sheet covers Corsica, Sardinia, southern Italy and Sicily, southern Yugoslavia, Albania, Greece, Bulgaria, western Turkey, and the north African coast from Alexandria to Tunisia. Metallogenic provinces and specific deposits are indicated, with their general geological context, age, morphology, nature of the mineral, principal metals, genetic type, and nature of the deposit, all depicted by means of colour coding or symbols. The accompanying mineral deposits lists are arranged in three sequences: geographical (in order of latitude within each country), alphabetical (by deposit name within each country), and by commodity.

This work is based on the BRGM's reference collection of polished sections and on20 years work by its mineralogists. Part one discusses the use of methods and describes the apparatus used. Determination tables are also provided based on commonly used characteristics such as paragenesis, reflectance, twinning etc. The main part describes 369 minerals in alphabetical order. Most have been photographed in polarised light and optical properties and principles of determination in reflected light are given as follows: colour in plane-polarised light, brireflectance and polishing characteristics; reflectance; anisotropy and colours with nicols crossed; associated minerals and paragenesis; occurrences; determination criteria; and x-ray powder diffraction data. A table of reflectance values in 15 wavelengths of the visible spectrum completes the description., This work is based on the BRGM's reference collection of polished sections and on20 years work by its mineralogists. Part one discusses the use of methods and describes the apparatus used. Determination tables are also provided based on commonly used characteristics such as paragenesis, reflectance, twinning etc. The main part describes 369 minerals in alphabetical order. Most have been photographed in polarised light and optical properties and principles of determination in reflected light are given as follows: colour in plane-polarised light, brireflectance and polishing characteristics; reflectance; anisotropy and colours with nicols crossed; associated minerals and paragenesis; occurrences; determination criteria; and x-ray powder diffraction data. A table of reflectance values in 15 wavelengths of the visible spectrum completes the description.

60 papers or extended abstracts are presented. Regional syntheses are given of deposits in Bavaria, the Rhine gorge area, the Bohemian massif, SW Poland, the Czech Carpathians, Macedonia, the Pacific region, southern Sweden, central Scotland, the English Pennines, the Armorican massif, the Massif Central, Provence, the Maures massif, Italy, Portugal, and central Morocco. Individual deposits discussed are those of Brioude-Massiac, Pontgibaud, Beaujeu, Noailhac-Saint Salvy, Villemagne, Chaillac, Porres, Pic Martin, Maurevieille, and Fontsante, in France, Penas de Haya, Montseny-Guilleries, Modesta, and Badajoz-Cordoue, in Spain, Monte Genis, in Sardinia, Moldava and Harrachov, in Czechoslovakia, and the Pennines, in the UK. The following section includes geochemical studies and genetic models, and the final papers are structural studies and prospecting guides., 60 papers or extended abstracts are presented. Regional syntheses are given of deposits in Bavaria, the Rhine gorge area, the Bohemian massif, SW Poland, the Czech Carpathians, Macedonia, the Pacific region, southern Sweden, central Scotland, the English Pennines, the Armorican massif, the Massif Central, Provence, the Maures massif, Italy, Portugal, and central Morocco. Individual deposits discussed are those of Brioude-Massiac, Pontgibaud, Beaujeu, Noailhac-Saint Salvy, Villemagne, Chaillac, Porres, Pic Martin, Maurevieille, and Fontsante, in France, Penas de Haya, Montseny-Guilleries, Modesta, and Badajoz-Cordoue, in Spain, Monte Genis, in Sardinia, Moldava and Harrachov, in Czechoslovakia, and the Pennines, in the UK. The following section includes geochemical studies and genetic models, and the final papers are structural studies and prospecting guides.

With the aim of improving seismic ground-motion models in Europe and reducing associated uncertainties, the compilation of a high-quality database of seismic-motion recordings and associated metadata is of primary importance. SIGMA research and development project, devoted to the improvement of seismic hazard estimates, methods and data for France and nearby regions, has been funding the implementation of RESORCE (Reference databaSe fOR seismiC ground-motion in Europe, Akkar et al., 2014).

International audience, In this paper, a method is described for inverting geoacoustic parameters of the seabed from short range field data recorded by single hydrophone. The original data in time domain are processed by a warping operator at first, and then the dispersion curve and the mode amplitude ratios are extracted separately from the warped data. The velocity and the density in the bottom are inverted from the dispersion curve, and the attenuation from the mode amplitude ratios, respectively. The performance of the method is examined using simulated data and then experimental data from the North Sea of China. The source used in the experiment was a small explosive charge that provided good signal to noise ratio over the frequency band from 200 Hz to 1 kHz. The depth of the water was about 30m, and the water sound speed was nearly constant with depth. The seabed geoacoustic parameters are inverted from the data received at different ranges from 2 to 14 km. The results from the different ranges are consistent with a simple half space model of the bottom. The seabed velocity is about 1600 m/s.