We report on the first comprehensive scientific drilling campaign to be completed in the Rochechouart impact structure, France, describing the various holes and the first visual inspection of the major lithologies encountered, in... more
We report on the first comprehensive scientific drilling campaign to be completed in the Rochechouart impact structure, France, describing the various holes and the first visual inspection of the major lithologies encountered, in reference to the IUGS nomenclature.
Research Interests:
ABSTRACT
Research Interests:
Research Interests: Geology and Humanities
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Contraindre l’histoire thermique des secteurs d’exploration et de prospection miniere permet de mieux comprendre et predire les processus de mineralisations et ainsi, d’etablir des modeles metallogeniques necessaires a l’evaluation des... more
Contraindre l’histoire thermique des secteurs d’exploration et de prospection miniere permet de mieux comprendre et predire les processus de mineralisations et ainsi, d’etablir des modeles metallogeniques necessaires a l’evaluation des ressources minerales. La reconstitution des paleo-champs de temperatures associees aux processus mineralisateurs necessite le couplage de plusieurs donnees analytiques telles que les donnees structurales, thermiques et geochimiques.
Research Interests: Geology and Humanities
L'etude microthermometrique des inclusions fluides a confirme que la mineralisation de Southwest Tintic se rattache au type porphyre cuprifere, et a permis en outre de degager ses caracteres specifiques : — Le debut de l'activite... more
L'etude microthermometrique des inclusions fluides a confirme que la mineralisation de Southwest Tintic se rattache au type porphyre cuprifere, et a permis en outre de degager ses caracteres specifiques : — Le debut de l'activite hvdrothermale est marque par la circulation de saumures riches en NaCl, KCl et, entre autres, en chalcopyrite (1 000 a 2 000 p. p. m. Cu) vers 700° C, a une pression de 2 a 3 kbar. — Une phase de decompression adiabatique se produit, qui provoque la mise en ebullition des fluides vers 600° C, 800 bar. On constate que les fluides ont ete satures en chalcopyrite au cours de la phase d'ebullition. Ce sont ces solutions sursaturees en cuivre qui deposent l'essentiel de la chalcopyrite qui constitue le gisement. — L'ebullition se poursuit alors que la pression et la temperature decroissent rapidement : les saumures sont alors egalement saturees en halite. — La fin de l'activite hydrothermale est marquee par l'arret de l'ebullition, a des pressions de l'ordre de 100 bar : les fluides alors pieges vers 400° C et au-dessous sont des liquides de salinite plus faible.
Research Interests:
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... more
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 primordial condition to have the most precise temperatures. Thus the calibration of the microthermometric stage is performed from −56 to +573 °C using reversible fusions or solid-solid transitions in standards as salts, ceramics, minerals or synthetic fluid inclusions. The nine transitions measured define a linear calibration curve with negative slope, showing a correction ranging from 1.6 to 16 °C between −60 and 600 °C. The vertical and lateral gradients (temperature bias) are estimated and discussed.
Research Interests:
ABSTRACT
Research Interests:
... Influence of dislocations on water leakage from fluid inclusions in quartz: a quantitative reappraisal PATRICK CORDIER1, JEAN CLAUDE DOUKHAN1 and CLAIRE RAMBOZ2 ... Pipe diffusion along dislocations does not significantly en hance the... more
... Influence of dislocations on water leakage from fluid inclusions in quartz: a quantitative reappraisal PATRICK CORDIER1, JEAN CLAUDE DOUKHAN1 and CLAIRE RAMBOZ2 ... Pipe diffusion along dislocations does not significantly en hance the kinetics of water leakage. ...
Research Interests:
Research Interests:
Research Interests: Geology and Geochemistry
Research Interests:
Research Interests:
Deep-seated fluids uplifted with Triassic diapirs in the SE basin, and minerals precipitated from evolved evaporitic fluids in the Oxfordian marls, have been characterized by Proton Induced X-ray Emission (PIXE) microanalysis. Trace... more
Deep-seated fluids uplifted with Triassic diapirs in the SE basin, and minerals precipitated from evolved evaporitic fluids in the Oxfordian marls, have been characterized by Proton Induced X-ray Emission (PIXE) microanalysis. Trace amounts of Fe, Cu, ± Zn, ± Ti, ± As, ± Br have been measured in both cases, emphasizing the metallogenic potential of the diapiric fluids, and their influence during early diagenesis of the Oxfordian marls. The low Sr-content of evaporitic fluids (<20 ppm) contrasts with the Sr-rich minerals deposited below the sea-floor surface.
Research Interests:
Fluid inclusions (FI) in diagenetic minerals and fissures were studied in two boreholes drilled on the Ardeche margin, MM1 and BA1 which crosscut the Uzer fault at the surface and at depth, respectively. Most FI and their host minerals... more
Fluid inclusions (FI) in diagenetic minerals and fissures were studied in two boreholes drilled on the Ardeche margin, MM1 and BA1 which crosscut the Uzer fault at the surface and at depth, respectively. Most FI and their host minerals were placed in the petrostructural scheme proposed for this part of the margin, which includes three main stages. (1) At the Triassic, evaporitic pore waters were diluted, and sulfates were recrystallized, remobilized into fractures at BA1 at T 3 and MnCO 3 (up to 20 et 2.5 mole % respectively), sometimes with correlative Fe-Mn variations. It developed in tension gashes, en echelon cracks, hydraulic fractures or crack seals under high pore fluid pressures to geopressured conditions (many dolomitic joints are horizontal). Secondary FI in vertical dolomite-quartz veins at -1729.25 m and in pre-Carnian vein anhydrite are two-phased and saline ( nearly equal 20 wt. % eq. NaCl; 101 degrees
Research Interests:
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... more
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 deep domains of the Shimanto paleo-accretionary complex, Japan, we first show that at temperatures of ~250°C, the fluid is a mixture of water and methane, in agreement with literature on similar terranes. In most of the studied area, we could observe only one, water-rich, kind of inclusion, while in a restricted region a second, methane-rich, kind of inclusion was also present, suggesting in the first case the circulation at depth of a single fluid and in the second case the coexistence of two fluid phases. We used then isochores of the methane-rich fluid inclusions to constrain the paleo- fluid pressure. In the present case, methane-rich inc...
Research Interests:
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).... more
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 a result of the incorporation of trace Mn2+ in its lattice. Aragonite can also be discriminated from calcite by its green CL. Carbonates are a major target for the search of life on Mars, and CL imagery could contribute to reveal carbonates in situ. Thomas et al. [1] have validated the concept of an electron lamp to make CL imagery of a rock surface placed in a martian CO2 atmosphere. We present 2 examples of terrestrial bacterial microstructures that are revealed by CL. (1) In Sinemurian sediments from the Montmiral borehole (Valence Basin, France), banded wavy calcite in contact with pyrite represents fossilized biofilms of sulfato-reduc...
Research Interests:
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... more
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 (OSUC) in Orléans. For maximum science return, all instruments on a single mission should ideally be tested with the same suite of relevant analogue materials. The ISAR lithothéque aims to fulfill this role by providing suitable materials to instrument teams [1]. The lithothèque is accompanied by an online database of all relevant structural, textural, and geochemical data (www.isar.cnrs-orleans.fr).The data base will also be available during missions to aid interpretation of data obtained in situ. Mars is the immediate goal for MSL-2011 and the new international Mars 2018 mission. The lithothèque thus presently contains relevant Mars...
Research Interests:
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.
Research Interests:
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... more
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 (cyanobacteria) from anoxygenic photosynthesisers (Chloroflexus-like bacteria, CFB) in samples obtained in 2011. After this preliminary investigation, we characterised the elemental composition of the different species of microorganisms, their extracellular substances (EPS), and the minerals precipitated on their surface. This study was made in-situ by µ-PIXE using the nuclear microprobe of the AIFIRA platform (CEN Bordeaux-Gradignan ; protons of 1.5 or 3MeV). With this microprobe it is possible to map the distribution of elements occurring in quantities down to several ppm, a resolution that is particularly favourable for studying microo...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
... Primed in USA 0016-7037/85/ 3.00 + .00 The PVTX-fO-t evolution of HiO-CC^-CHrbearing fluid in a wolframite vein: Reconstruction from fluid inclusion ... Then, starting from Tmin, the inclusion was cooled a few degrees to allow the... more
... Primed in USA 0016-7037/85/ 3.00 + .00 The PVTX-fO-t evolution of HiO-CC^-CHrbearing fluid in a wolframite vein: Reconstruction from fluid inclusion ... Then, starting from Tmin, the inclusion was cooled a few degrees to allow the melting solid to regrow and become more visible ...
Research Interests:
Research Interests:
Research Interests:
Research Interests: Geology, Geochemistry, Mineralogy, Emerald, Fluorine, and 6 moreTopaz, Wollastonite, Sphalerite, Fluorite, Amphibole, and ionic bonding
ABSTRACT
Research Interests:
Pyrite samples from the Radka epithermal, replacement type, volcanic rock-hosted copper deposit, Bulgaria, have been studied using near-infrared (IR) microscopy. Two generations of pyrite based on their textures, composition and behaviour... more
Pyrite samples from the Radka epithermal, replacement type, volcanic rock-hosted copper deposit, Bulgaria, have been studied using near-infrared (IR) microscopy. Two generations of pyrite based on their textures, composition and behaviour in IR light can be distinguished. ...
1Institut des Sciences de la Terre, Université de Genève, 1205-Genève, Switzerland; 2Sofia University St. Kliment Ohridski, 1504-Sofia, Bulgaria; 3ISTO-CNRS, 45071-Orléans, France; E-mail: kalin.kouzmanov@terre.unige.ch ... Abstract.... more
1Institut des Sciences de la Terre, Université de Genève, 1205-Genève, Switzerland; 2Sofia University St. Kliment Ohridski, 1504-Sofia, Bulgaria; 3ISTO-CNRS, 45071-Orléans, France; E-mail: kalin.kouzmanov@terre.unige.ch ... Abstract. The Late Cretaceous ...
Research Interests:
ABSTRACT
Research Interests: Geology, Geochemistry, Quartz, Precambrian, Mineral, and 5 moreAntimony, Placer Mining, Prospecting, Lode, and Placer Deposit
Relations between Au / Sn-W mineralizations and late hercynian ... E. Gloaguen, A. Chauvet, Y. Branquet, O. Gerbeaud & C. Ramboz Institut des Sciences de la Terre d'Orléans UMR CNRS 6113, Université d'Orléans, BP 6759, 45067... more
Relations between Au / Sn-W mineralizations and late hercynian ... E. Gloaguen, A. Chauvet, Y. Branquet, O. Gerbeaud & C. Ramboz Institut des Sciences de la Terre d'Orléans UMR CNRS 6113, Université d'Orléans, BP 6759, 45067 Orléans Cedex2, France
Research Interests:
The present study is focused on the so-called High Temprature Reaction Zone of the Oman ophiolite, a thin zone located between the roots of the sheeted dyke complex and the high-level gabbros marking the roof of the fossil magma chambers.... more
The present study is focused on the so-called High Temprature Reaction Zone of the Oman ophiolite, a thin zone located between the roots of the sheeted dyke complex and the high-level gabbros marking the roof of the fossil magma chambers. The distribution of diabases, chloritised dykes, spilitized dykes and epidosites (in the order of increasing hydrothermal alteration) was studied along continuous outcrops of the lower sheeted dyke complex in three selected areas. The Muwaylah section, in the Haylayn massif, representing a fossil ...
Research Interests:
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... more
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 folded during the Hercynian orogeny. This area underwent tectonic, metamorphic and hydrothermal events that explain the presence of several base metal deposits like Hajjar. The application of Raman Spectroscopy of Carbonaceous Material geothermometry (RSCM) has revealed new temperature peaks superior to 500°C that were unrevealed by other methods (fluid inclusion, chlorite thermometry). This new data set will allow a better understanding of the thermal history and of the mineralization processes in the Guemassa massif.
Research Interests: Geology and Geochemistry
The future ExoMars mission (2018) to determine habitability and to search for traces of past life on Mars has a payload comprising a complementary variety of instruments. We simulated mission procedure by blind-testing the ExoMars... more
The future ExoMars mission (2018) to determine habitability and to search for traces of past life on Mars has a payload comprising a complementary variety of instruments. We simulated mission procedure by blind-testing the ExoMars instruments using two unknown terrestrial analogue samples. The data were then then evaluated, also “blind”, by geologists. The results demonstrate that the ExoMars instrument suite provides good data.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. The Rochechouart 2017-Cores Rescaled: Major Features P. Lambert, C Alwmark, D. Baratoux, S. Bouley, A. Brack, P Bruneton, E Buchner, P. Claeys, M Dence, A Nomade, et al.
Research Interests:
Research Interests:
Research Interests:
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... more
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 to surface and subsurface processes occurring on Mars will help understand and interpret martian features. The Skouriotissa mine in Cyprus is an open pit copper mine (consisting of a very massive sulphide deposit, VMS) exposing the upper pillow basalt formation in the Troodos ophiolitic zone. The basalt has been altered by (1) hydrothermal and deuteritic processes and (2) acidic water (pH <5) associated with the mining working. We have analysed the mineralogical evolution of the basalt through different alteration facies (phyllosilicates, including Mg-smectite, vermiculite, nontronite, and zeolites), depending on the type of alteration. ...
Research Interests:
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... more
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 fashion, by comparison with standards. At the end of the 70's and in the 80's, PIXE (Proton Induced X-Ray Emission) by contrast was applied in a way that preserved the possibility of an absolute application: the computer programs developed to interpret PIXE spectra calculate matrix effects and also integrate instrumental factors (e.g., Maxwell et al., 1989). In spite of this advantage, and also despite the fact that PIXE application extends to trace element analysis, the development of PIXE in the scientific community was sluggish, in deep contrast with the widespread applications of EPMA. In the field of Earth Sciences particul...
Research Interests:
ISAR (www.isar.cnrs-orleans.fr) contains relevant lab characterised igneous and sedimentary rocks and minerals for testing instruments for in situ Mars missions.