Claire Ramboz

CNRS Orleans Campus · Institut des Sciences de la Terre d'Orléans (ISTO)

Drill core petrography from the Rochechouart impact structure.

The Linkam THMS 600 microthermometric stage use the fluid inclusions to deliver quantitative paleo-temperatures of subsurface past environments that are critical not only for understanding past climate evolution but also to validate the outcome of predictive models of future climates. In this case, the calibration of the microthermometric stage is...

The present work aims at understanding the tectonic evolution of the Jebilet massif, Morocco, during the Late Paleozoic as constrained by structural, metamorphic, and geochronological studies. From Late Devonian to Early Carboniferous, bordering faults controlled the opening of the Jebilet intracontinental basin (D0 stage) as shown by sedimentary i...

Fossil structures, such as exhumed accretionary prisms, are the only direct recorders of the fluids wetting the plate interface near the base of the seismogenic zone. By studying exhumed accretionary prisms, it is thus possible to determine the physicochemical properties of fluids and the geometry and dynamics of their circulation. We considered he...

First results from the Rochechouart impact crater drilling campaign.

The pressure of deep fluids in subduction zones is a major control on plate boundary strength and earthquake genesis. The record, by methane-rich fluid inclusions, of large (~ 50–100 MPa) and instantaneous pressure variations in the Shimanto Belt (Japan) points to the presence of large fluid overpressure at depth (300–500 MPa, ~ 250 °C). To further...

The Anti-Atlas belt is well known for its numerous copper deposits. It displays also a complex geological, metallogenic and tectonic history which is challenging for mining companies in order to better understand and prospect these Cu-deposits. In the Bou Azzer-El Graara inlier, these deposits are hosted as well within the Precambrian basement as w...

L’Anti Atlas marocain recèle de nombreuses occurrences cuprifères, encaissées aussi bien dans le socle précambrien que dans la couverture paléozoïque. Ces minéralisations ont donné lieux à de multiples exploitations, d’importance diverse, certaines étant encore en activité aujourd’hui. L’augmentation de la demande mondiale en cuivre durant cette de...

Copper mineralization in sedimentary cover is well known in association with Pb and/or Zn in Sedex, Kupferschiefer, Mississippi Valley-Type, or Red bed deposits. In spite of great economic potential, the syngenetic versus epigenetic origin of widespread Cu occurrences in the Adoudounian sedimentary cover, in the Moroccan Anti Atlas, remains debated...

This study aims at precising the thermal history of the Guemassa massif and that of the Hajjar polymetallic deposit, by using a recently-developed method: the Raman Spectroscopy of Carbonaceous Material (e.g. Beyssac et al 2002; Lahfid et al 2010). The Guemassa massif belongs to the Moroccan Meseta domain and is mainly composed of Palaeozoic rocks...

Siliceous hot-spring deposits, or sinters, typically form in active, terrestrial (on land), volcanic terrains where magmatically heated waters circulating through the shallow crust emerge at the Earth’s surface as silica-charged geothermal fluids. Geyserites are sinters affiliated with the highest temperature (~ 75-100 °C), natural geothermal fluid...

For supercritical fluids there is a wedge-shaped region called Widom region, where several physico-chemical quantities (e.g. compressibility, heat capacities, density, thermal expansivity, speed of sound) show anomalous behaviour. In this paper, several Widom lines of supercritical CO2 have been computed with the Wagner–Span reference equation of s...

The future ExoMars rover mission (ESA/Roscosmos), to be launched in 2018, will investigate the habitability of the Martian surface and near subsurface, and search for traces of past life in the form of textural biosignatures and organic molecules. In support of this mission, a selection of relevant Mars analogue materials has been characterised and...

Gold have been recently recognized in the Tighza (formerly Jebel Aouam) district, in the Hercynian belt of central Morocco. This district has long been known for its W mineralization, as well as major Pb-Ag-Zn, and minor Sb-Ba deposits, all geographically associated with late-Hercynian calc-alkaline magmatism. Gold mineralization in the district is...

We give arguments showing that the Pb Ag Ba F Tl anomalies on the 200 Ma paleo-(sub)surface in western Europe likely have an impact-driven epithermal origin. We propose that they derive from the dust cloud induced by a bolide fall at Rochechouart (NW French Massif Central, France), then removal by rain and percolation along reactivated crustal line...

In paleo-accretionary prisms and the shallow metamorphic domains of orogens, circulating fluids trapped in inclusions are commonly composed of a mixture of salt water and methane, producing two types of fluid inclusions: methane-bearing aqueous and methane-rich gaseous fluid inclusions. In such geological settings, where multiple stages of deformat...

Instruments for surface missions to extraterrestrial bodies should be cross-calibrated using a common suite of relevant materials. Such work is necessary to improve instrument performance and aids in the interpretation of in-situ measurements. At the CNRS campus in Orléans, the Observatoire des Sciences de l'Univers en région Centre (OSUC) has crea...

The nature of the fluids involved in the deep plate interface in subduction zones is difficult to constrain, as it incorporates many potential sources (sea water trapped in pores, water from dehydration reactions, fluid from the depths of the subduction channel or from the slab). Using Raman analysis of fluid inclusions in quartz veins from the dee...

The Jabali deposit (3.8 Mt at 16% Zn, 2% Pb and 132 g/t Ag) is hosted by dolomitized platform carbonates of Kimmeridgian age at the southwestern edge of the oil-producing Wadi al Jawf rift basin in northern Yemen. Paleogeographical reconstructions demonstrate that tensional synsedimentary tectonic activity from the Late Jurassic to Early Cretaceous...

ISAR (www.isar.cnrs-orleans.fr) contains relevant lab characterised igneous and sedimentary rocks and minerals for testing instruments for in situ Mars missions.

In this investigation, we present a mineralogical study of altered crustal basalts exposed at the Skouriotissa mine on Cyprus analog to martian surface.

Here we present the results of the synthesis of three samples of artificial basalts, similar to basalts observed in the crater Gusev on Mars.

Liquid water at atmospheric pressure can be supercooled to -41°C (ref. ) and superheated to +302°C (ref. ). Experiments involving fluid inclusions of water in quartz suggest that water is capable of sustaining pressures as low as -140 MPa before it breaks by cavitation. Other techniques, for which cavitation occurs consistently at around -30MPa (re...

The analytical technique PIXE experiment for measuring light and heavy elements concentration inside different samples of soil and residual water collected in the region of Safi-El Jadida, where an industrial complex resided, was performed. The same method was used to investigate the presence of elements ranging from silicon to lead in different so...

Water is famous for its anomalies, most of which become dramatic in the supercooled region, where the liquid is metastable with respect to the solid. Another metastable region has been hitherto less studied: the region where the pressure is negative. Here we review the work on the liquid in the stretched state. Characterization of the properties of...

Analyses by the Mars Exploration Rover (MER), Spirit, of Martian basalts from Gusev crater show that they are chemically very different from terrestrial basalts, being characterized in particular by high Mg- and Fe-contents. To provide suitable analog basalts for the International Space Analogue Rockstore (ISAR), a collection of analog rocks and mi...

Basalts are the prevalent rock type on Mars and the products of aqueously altered basalts are of particular interest tracers or subsurface processes. We present an analogue site on Earth: the skouriotissa mine in Cyprus.

In order to prepare the next in situ space missions we have created a « lithothèque » of analogue rocks for calibrating and testing future (and existing) space flight instruments. This rock collection is called the International Space Analogue Rockstore (ISAR) and is hosted in the CNRS and the Observatoire des Sciences de l'Univers en Region Centre...

Basalts are the prevalent rock type on Mars and the products of aqueously altered basalts and hydrated minerals associated with basalts are of particular interest as possible tracers of a past, slightly more clement climate on the planet and/or magmatic processes [1,2]. Study of alteration processes of basalts on Earth that show some similarities t...

Solids irradiated by a 10-20 keV electron beam emit ligth in the UV-visible range, which is called cathodoluminescence (CL). CL imagery is a powerful tool for visualizing minerals and their internal structures (lattice defects, zoning). For example, terrestrial calcite, either of sedimentary or biogenic origin, often display a bright orange CL, as...

Physico-chemical and biological micro-scale environmental parameters within microbial mats formed in hypersaline conditions favour the precipitation of minerals, such as carbonates. We used optical microscopy and the technique "Fluorescence Induction Relaxation » (FIRe) to differentiate the photosynthetic activity of oxygenic photosynthesisers (cya...

High helium contents will be generated within minor actinide doped uranium dioxide blankets which could be used in fourth generation reactors. In this framework, it is essential to improve our understanding of the type of damage which a pellet could incur as a result of extensive helium build-up. This paper is an attempt at tackling this issue. Sin...

There are no suitable terrestrial analogues for martian basalts, which are richer in Fe and Mg. We present the results of a preliminary experiment to synthesise martian basalts based on the Sprit data from Gusev Crater.

The ESAR is a collection of well-characterised planetary analogue rocks and minerals that can be used for testing in situ instrumentation for planetary exploration. An online database of all relevant structural, compositional and geotechnics information is also available to the instrument teams and to aid data interpretation during missions.

The Callovian–Oxfordian (COx) clayey unit is being studied in the Eastern part of the Paris Basin at depths between 400 and 500 m depth to assess of its suitability for nuclear waste disposal. The present study combines new mineralogical and isotopic data to describe the sedimentary history of the COx unit. Petrologic study provided evidence of the...

In order to reply to the exobiological goals of the 2018 MAX-C/ExoMars mission, the Orléans-OSUC analogue rock collection and database contains well characterised Mars analogue rocks and minerals for use in instrument testing and in situ missions.

The Orléans-OSUC analogue rock collection and database contains well characterised igneous, sedimentary, and hydrothermal rocks and minerals for use in instrument testing and in situ missions and specifically the 2018 Max-C/ExoMars mission.

A pluridisciplinary approach was used to define iodine immobilization mechanisms by biocarbonates in a natural marine carbonate-bearing clayey formation. For this purpose, different techniques of observation (optical microscope, scanning electron microscope (SEM), cathodoluminescence (CL)) and of analyses (infrared spectrometry (IR), electron micro...

ExoMars has joined up with the American Max-C rover in a joint, two rover mission to Mars in 2018. The science objectives of ExoMars are to search for traces of past or present life and to document the water/geochemical environment as a function of depth in the shallow subsurface. Max-C seeks to determine the habitability of the surface of Mars wit...

The Orléans-Lithothèque - an analogue rockstore for in situ missions Nicolas Bost, Frances Westall, Claire Ramboz, Axelle Hubert, Derek Pullan, Beda Hofmann, Elisabeth Vergès, Michel Viso, Jorge Vago, Christelle Briois, Bruno Scaillet, Michel Tagger Instruments for in-situ missions to extraterrestrial bodies should ideally be cross calibrated using...

A synthetic pure water fluid inclusion showing a wide temperature range of metastability (Th − Tn ͌ 50°C; temperature of homogenization Th = 144°C and nucleation temperature of Tn = 89°C) was selected to make a kinetic study of the lifetime of an isolated microvolume of superheated water. The occluded liquid was placed in the metastable field by is...

We have performed a kinetic study of the lifetime of superheated aqueous solutions trapped as isolated microvolumes in quartz. The main physico-chemical characteristics of the four studied synthetic fluid inclusions (FI) are listed in the Table. The range of metastability (Th - Tn) of the selected inclusions was between 22° and 85.5°C which corresp...

Vlaykov Vruh–Elshitsa represents the best example of paired porphyry Cu and epithermal Cu–Au deposits within the Late Cretaceous Apuseni–Banat–Timok–Srednogorie magmatic and metallogenic belt of Eastern Europe. The two deposits are part of the NW trending Panagyurishte magmato-tectonic corridor of central Bulgaria. The deposits were formed along th...

The metastable superheated solutions are liquids in transitory thermodynamic equilibrium inside the stability domain of their vapor (whatever the temperature is). Some natural contexts should allow the superheating of natural aqueous solutions, like the soil capillarity (low T superheating), certain continental and submarine geysers (high T superhe...

Introduction: The Jurassic Plateau of l'Ile Crémieu, north of the Cenozoic Valence Basin, hosts a dense karstic network. In the Loras quarry, flat-lying oolithic bajocian carbonates are crosscut by two sets of fractures, structurally compatible with the NNE-SSW

Studies of natural CO2 analogues bring key information on the factors governing the long term (>1My) stability/instability of future anthropogenic CO2 storages. The main objective of this work is to trace the deep-origin CO2 migrations in fractures in the Montmiral CO2 deep natural occurrence (Valence Basin, SE France). The final objective is to do...

The morphologic study of the surface of Mars reveals that liquid water existed during the first few hundred millions of years of the planet's history (e.g. Smith et al., 1999). The flow of water produced extensive erosion in some place, but also large sedimentary basins. With a long enough duration of the presence of liquid water and the oxidation...

X-Ray-based analytical methods can be applied in an absolute fashion, provided that matrix effects are calculated and that parameters related to instrumental factors are controlled (Newbury, 1986). When EPMA (Electron Probe Micro Analysis) was conceived at the end of the 60's, this potentiality was abandoned, as the instrument works in a relative f...

A characteristic feature of the nuclear microprobe using a 3 MeV proton beam is the long range of particles (around 70 \mu m in light matrices). The PIXE method, with EDS analysis and using the multilayer approach for treating the X-ray spectrum allows the chemistry of an intra-crystalline inclusion to be measured, provided the inclusion roof and t...

In this work, PIXE experiments were performed for measuring heavy and light elements' (ranging from aluminium to lead) concentrations inside various polluted and unpolluted soils as well as liquid samples collected from different phosphate factory sewers in the El Jadida-Safi Atlantic coastal region (Morocco). In addition, uranium ((238)U) and thor...