Search

Your search keyword '"Verati, Chrystele"' showing total 33 results
Start Over Author "Verati, Chrystele"
33 results on '"Verati, Chrystele"'

4. Petrology, Geochemistry and Petrogenesis of the Sidi El Hemissi Triassic ‘Ophites’ (Souk Ahras, NE Algeria)

Author

Laouar, Rabah, Zanouda, Halima Saadia, Salmi-Laouar, Sihem, Sebai, Amar, Verati, Chrystèle, Bouhlel, Salah, Boyce, Adrian J., Pisello, Anna Laura, Editorial Board Member, Hawkes, Dean, Editorial Board Member, Bougdah, Hocine, Editorial Board Member, Rosso, Federica, Editorial Board Member, Abdalla, Hassan, Editorial Board Member, Boemi, Sofia-Natalia, Editorial Board Member, Mohareb, Nabil, Editorial Board Member, Mesbah Elkaffas, Saleh, Editorial Board Member, Bozonnet, Emmanuel, Editorial Board Member, Pignatta, Gloria, Editorial Board Member, Mahgoub, Yasser, Editorial Board Member, De Bonis, Luciano, Editorial Board Member, Kostopoulou, Stella, Editorial Board Member, Pradhan, Biswajeet, Editorial Board Member, Abdul Mannan, Md., Editorial Board Member, Alalouch, Chaham, Editorial Board Member, O. Gawad, Iman, Editorial Board Member, Amer, Mourad, Series Editor, Doronzo, Domenico M., editor, Schingaro, Emanuela, editor, Armstrong-Altrin, John S., editor, and Zoheir, Basem, editor

Published
2019
Full Text
View/download PDF

8. The Jurassic–Cretaceous basaltic magmatism of the Oued El-Abid syncline (High Atlas, Morocco): Physical volcanology, geochemistry and geodynamic implications

Author

Bensalah, Mohamed Khalil, Youbi, Nasrrddine, Mata, João, Madeira, José, Martins, Línia, El Hachimi, Hind, Bertrand, Hervé, Marzoli, Andrea, Bellieni, Giuliano, Doblas, Miguel, Font, Eric, Medina, Fida, Mahmoudi, Abdelkader, Beraâouz, El Hassane, Miranda, Rui, Verati, Chrystèle, De Min, Angelo, Ben Abbou, Mohamed, and Zayane, Rachid

Published
2013
Full Text
View/download PDF

9. Tectono-metamorphic evolution of shallow crustal levels within active volcanic arcs. Insights from the exhumed Basal Complex of Basse-Terre (Guadeloupe, French West Indies)

Author

Favier Alexiane, Lardeaux Jean-Marc, Legendre Lucie, Verati Chrystele, Philippon Melody, Corsini Michel, Münch Philippe, and Ventalon Sandra

Subjects
arc-related metamorphism, Lesser Antilles, Guadeloupe, Basal Complex, tectono-metamorphic evolution, hydrothermal fluids, Geology, QE1-996.5
Abstract

In order to decipher the tectono-metamorphic evolution of shallow crustal levels of the active volcanic arc of the Guadeloupe archipelago (Lesser Antilles) we present new geochemical, geochronological, mineralogical and structural investigations of the so-called Basal Complex, the oldest and most eroded volcanic complex of Basse-Terre in Guadeloupe. Based on geochemical and mineralogical criteria we propose an updated geological map of this northern area of Basse-Terre. Using 40Ar–39Ar geochronology we demonstrate first that the eroded “Gros Morne” of Deshaies belong to the Basal Complex, and second that this complex is characterized by 4.3 to 2 Ma old volcanism. Structural analysis reveals a long-lived deformation history with the development through time of N80-N100 schistose zones; N110-N140 and N160-N10 oriented hydrothermal breccias and N140-N150 brittle normal faults. The boundary between the Basal Complex and the southernmost Septentrional Chain corresponds to a series of faults with N 150° and N 50° main directions. Detailed mineralogical and petrological investigations, including thermodynamic modeling, allow the identification of three phases of post-magmatic mineralogical transformations with first a high-temperature stage under Greenschist to sub-Greenschist facies conditions (0.6–2 kbar for 250–300 °C), a re-equilibration under Zeolite facies conditions and finally a sub-surface alteration. The consistency between P–T conditions of metamorphism and the present day measured geothermal gradient demonstrates that the metamorphic pattern is the record of hydrothermal fluids circulation during building and cooling of the Lesser Antilles magmatic arc. The tectono-metamorphic evolution recognized in the Basal Complex enables us to propose a conceptual model for heat and fluid transport within shallow crustal levels of the Guadeloupe active volcanic arc.

Published
2019
Full Text
View/download PDF

13. Thermal fatigue as the origin of regolith on small asteroids

Author

Delbo, Marco, Libourel, Guy, Wilkerson, Justin, Murdoch, Naomi, Michel, Patrick, Ramesh, K.T., Ganino, Clement, Verati, Chrystele, and Marchi, Simone

Subjects
Asteroids -- Models -- Observations, Diurnal cycles (Earth sciences) -- Research, Regolith -- Research -- Thermal properties -- Mechanical properties -- Origin, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Space missions (1,2) and thermal infrared observations (3) have shown that small asteroids (kilometre-sized or smaller) are covered by a layer of centimetre-sized or smaller particles, which constitute the regolith. Regolith generation has traditionally been attributed to the fall back of impact ejecta and by the break-up of boulders by micrometeoroid impact (4,5). Laboratory experiments (6) and impact models (4), however, show that crater ejecta velocities are typically greater than several tens of centimetres per second, which corresponds to the gravitational escape velocity of kilometre-sized asteroids. Therefore, impact debris cannot be the main source of regolith on small asteroids (4). Here we report that thermal fatigue (7-9), a mechanism of rock weathering and fragmentation with no subsequent ejection, is the dominant process governing regolith generation on small asteroids. We find that thermal fragmentation induced by the diurnal temperature variations breaks up rocks larger than a few centimetres more quickly than do micrometeoroid impacts. Because thermal fragmentation is independent of asteroid size, this process can also contribute to regolith production on larger asteroids. Production of fresh regolith originating in thermal fatigue fragmentation maybe an important process for the rejuvenation of the surfaces of near-Earth asteroids, and may explain the observed lack of low-perihelion, carbonaceous, near-Earth asteroids (10)., The collisional and gravitational re-accumulation processes by which small asteroids are formed probably result in the creation of surfaces composed of boulders (11). These boulders are broken up by micrometeoroid [...]

Published
2014

15. The Concept of Exhumed Analogue for Characterization of High-Energy Geothermal Reservoir: an Example from Les Saintes Island (Guadeloupe Archipelago, Lesser Antilles) and Consequences for Exploration

Author

Favier, Alexiane, Lardeaux, Jean-Marc, Verati, Chrystele, Corsini, Michel, Münch, Philippe, Ventalon, Sandra, Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]), ADEME - Programme Investissement d'Avenir, and IGA

Subjects
hydrothermal transformations, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, model for fluids pathways, [SDU]Sciences of the Universe [physics], [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, exhumed paleo-reservoir, high-enthalpy geothermal field, [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Lesser Antilles volcanic arc, [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

International audience; The recognition of a fossil equivalent of the active geothermal system of the Basse-Terre Island in Guadeloupe archipelago (Lesser Antilles arc) in Terre-de-Haut Island (Les Saintes archipelago) allow us to better constrain the structure, the mineralogy and the petrological characters of the deep parts of an active geothermal reservoir. First, we demonstrate the occurrence, in Terre-de-Haut Island, of an exhumed analogue of the deeper parts Bouillante geothermal field. In this exhumed paleo-geothermal reservoir we characterize the nature and the P-T evolutions of the hydrothermal mineral associations in relation with fluids transfers. Moreover, high-temperature hydrothermal activity is coeval with the development of ductile tectonic structures, particularly schistose corridors, and is dated at 2.59 ± 0.12 Ma on white micas, involving maximum activity of 600 ky. These data provide a conceptual model, including brittle-ductile transition located at a depth between 2.5 and 4 km. In this way, brittle and ductile tectonic structures are efficient drains to connected vertical and lateral fluids and heat transfers. This may provide new guides for exploration of geothermal resources in volcanic arcs.

Published
2021

16. Structure and petrology of the Edolo diabase and implications for the Alpine tectonics in the Southern Alps, from rifting to continental collision

Author

Filippi, Marco, Gregorio, Pulcini, Rebay, Gisella, Corsini, Michel, Lardeaux, Jean-Marc, Roda, Manuel, Spalla, Maria Iole, Verati, Chrystele, Zanoni, Davide, and Sciencesconf.org, CCSD

Subjects
[SDU] Sciences of the Universe [physics], Alpine collision, lamprophyre dykes, Triassic rifting, central Southern Alps, greenschist facies metamorphism
Published
2021

17. Ar-40/Ar-39 dating of basaltic rocks and the pitfalls of plagioclase alteration

Author

Jiang, Qiang, Jourdan, Fred, Olierook, Hugo K. H., Merle, Renaud E., Verati, Chrystele, Mayers, Celia, Jiang, Qiang, Jourdan, Fred, Olierook, Hugo K. H., Merle, Renaud E., Verati, Chrystele, and Mayers, Celia

Abstract

Ar-40/Ar-39 geochronology is one of the most important techniques for constraining the timing of basaltic events due to the paucity of suitable minerals in basalts for other geochronological techniques such as U-Pb (e.g., zircon, baddeleyite). Among a variety of materials from basaltic rocks that have been used for Ar-40/Ar-39 dating, plagioclase is the most important due to its common presence in basalts as a primary crystallizing phase, and its transparency so that fresh grains can be selected during sample preparation. However, plagioclase Ar-40/Ar-39 geochronology has often been compromised by alteration (e.g., sericitization by hydrothermal events), which, in practice, is difficult to identify using a petrographic microscope when the amount of alteration is low (e.g., <1%). We used laboratory step-heating experiments and theoretical simulations to characterize the Ar-40/Ar-39 age and Ca/K spectra of altered plagioclase so that Ar-40/Ar-39 dating results on altered samples can be identified and better interpreted. The step-heating experiments and theoretical simulations yielded consistent results, and show that with the presence of even a tiny amount of sericite (similar to 0.01% for K-poor samples and similar to 0.1% for K-rich samples), the plagioclase samples yielded alteration plateau ages that are 3%-4% younger than the crystallization age. The difference between the alteration age of sericitized plagioclase and its crystallization age is primarily controlled by the time lapse between the crystallization and sericitization events, but also by the Ca/K ratios of the plagioclase. For plagioclase samples that experienced the same alteration event, the higher the Ca/K ratio is, the more sensitive the Ar-40/Ar-39 age is to alteration. We propose that the alteration signatures of plagioclase can be effectively identified through inspecting the Ar-40/Ar-39 age spectra, the Ca/K spectra, and the degassing curves. We also investigated the effect of sericitization

Published
2021
Full Text
View/download PDF

19. Synchrony of the Central Atlantic magmatic province and the Triassic-Jurassic boundary climatic and biotic crisis

Author

Marzoli, Andrea, Bertrand, Herve, Knight, Kim B., Cirilli, Simonetta, Buratti, Nicoletta, Verati, Chrystele, Nomade, Sebastien, Renne, Paul R., Youbi, Nasrrddine, Martini, Rossana, Allenbach, Karin, Neuwerth, Ralph, Rapaille, Cedric, Zaninetti, Louisette, and Bellieni, Giuliano

Subjects
Magma -- Research, Geology -- Research, Earth sciences
Abstract

The evolution of life on Earth is marked by catastrophic extinction events, one of which occurred ca. 200 Ma at the transition from the Triassic Period to the Jurassic Period (TrJ boundary), apparently contemporaneous with the eruption of the world's largest known continental igneous province, the Central Atlantic magmatic province. The temporal relationship of the Tr-J boundary and the province's volcanism is clarified by new multidisciplinary (stratigraphic, palynologic, geochronologic, paleomagnetic, geochemical) data that demonstrate that development of the Central Atlantic magmatic province straddled the Tr-J boundary and thus may have had a causal relationship with the climatic crisis and biotic turnover demarcating the boundary. Keywords: Central Atlantic magmatic province, flood basalts, mass extinction, Triassic-Jurassic boundary, Morocco.

Published
2004

23. Reply to Comment on “The Jurassic–Cretaceous basaltic magmatism of the Oued El-Abid syncline (High Atlas, Morocco): Physical volcanology, geochemistry and geodynamic implications” by André Michard et al. (2013) [J. Afr. Earth Sci. 88 (December) (2013) 101–105]

Author

Bensalah, Mohamed Khalil, Youbi, Nasrrddine, Mata, João, Madeira, José, Martins, Línia, Font, Eric, Medina, Fida, Marzoli, Andrea, Hachimi, Hind El, Bertrand, Hervé, Bellieni, Giuliano, Doblas, Miguel, Mahmoudi, Abdelkader, Beraâouz, El Hassane, Miranda, Rui, Verati, Chrystèle, Min, Angelo De, Abbou, Mohamed Ben, and Zayane, Rachid

Published
2016
Full Text
View/download PDF

26. Castellar – Pendimoun (Alpes-Maritimes). Avancement des travaux de recherche en 2014 (contribution 9)

Author

Binder, Didier, Battentier, Janet, Bellot-Gurlet, Ludovic, Beyries, Sylvie, Bonnardin, Sandrine, Bouby, Laurent, Carré, Alain, Cassard, Laura, Corsini, Michel, Delhon, Claire, De Stefanis, Cristina, Drieu, Léa, Dubar, Michel, Duday, Henri, Durrenmath, Gilles, Gabriele, Marzia, Girard, Michel, Goude, Gwenaëlle, Gourichon, Lionel, Hamon, Caroline, Jacomet, Suzanne, Julien, Marion, Lardeaux, Jean-Marc, Lepère, Cédric, Mazuy, Arnaud, Pradeau, Jean-Victor, Quatrehomme, Gérald, Rageot, Maxime, Regert, Martine, Sénépart, Ingrid, Thiebault, Stephanie, Verati, Chrystele, Zemour, Aurélie, Culture et Environnements, Préhistoire, Antiquité, Moyen-Age (CEPAM), Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Gestion des ressources naturelles , environnements et sociétés (GReNES), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies (MONARIS), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Centre d'Études Préhistoire, Antiquité, Moyen-Age (CEPAM), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, Géoazur (GEOAZUR 6526), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie (PACEA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Anthropologie Mémoire, Identité et Cognition Sociale (LAMIC), Laboratoire méditerranéen de préhistoire Europe-Afrique (LAMPEA), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), Trajectoires - UMR 8215, Université Paris 1 Panthéon-Sorbonne (UP1)-Centre National de la Recherche Scientifique (CNRS), Centre de Mise en Forme des Matériaux (CEMEF), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'ingénierie osteo-articulaire et dentaire (LIOAD), Université de Nantes (UN)-IFR26-Institut National de la Santé et de la Recherche Médicale (INSERM), Géoazur (GEOAZUR 7329), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Mécanismes biologiques des Altérations du Tissu Osseux (MATOs), UMR E4320 (TIRO-MATOs), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Médecine Légale et Anthropologie médico-légale, Archéozoologie, archéobotanique : sociétés, pratiques et environnements (AASPE), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Ausonius-Institut de recherche sur l'Antiquité et le Moyen âge, Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), LabEx Sciences archéologiques de Bordeaux (LASCARBX), Université Bordeaux Montaigne-Université de Bordeaux (UB), Service régional de l'Archéologie Provence-Alpes-Côte d'Azur, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), Mines Paris - PSL (École nationale supérieure des mines de Paris), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux (UB)-Université Bordeaux Montaigne (UBM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Université de Bordeaux (UB)-Université Bordeaux Montaigne, Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Castellar, Archéologie, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, Néolithique, Pendimoun, Alpes-Maritimes
Published
2014

32. Intercalibration of the Hb3gr 40Ar/39Ar dating standard

Author

Jourdan, Fred, Verati, Chrystele, and Féraud, Gilbert

Subjects
*GEOLOGICAL time scales, *AMPHIBOLES, *BIOTITE, *VOLCANIC ash, tuff, etc.
Abstract

Abstract: The 40Ar/39Ar dating technique is based on the knowledge of the age of neutron fluence monitors (standards). Recent investigations have improved the accuracy and precision of the ages of most of the Phanerozoic-aged standards (e.g. Fish Canyon Tuff sanidine (FCs), Alder Creek sanidine, GA1550 biotite and LP-6 biotite); however, no specific study has been undertaken on the older standards (i.e. Hb3gr hornblende and NL-25 hornblende) generally used to date Precambrian, high Ca/K, and/or meteoritic rocks. In this study, we show that Hb3gr hornblende is relatively homogenous in age, composition (Ca/K) and atmospheric contamination at the single grain level. The mean standard deviation of the 40Ar⁎/39ArK (F-value) derived from this study is 0.49%, comparable to the most homogeneous standards. The intercalibration factor (which allows direct comparison between standards) between Hb3gr and FCs is R FCs Hb3gr =51.945±0.167. Using an age of 28.02 Ma for FCs, the age of Hb3gr derived from the R-value is 1073.6±5.3Ma (1σ; internal error only) and ±8.8Ma (including all sources of error). This age is indistinguishable within uncertainty from the K/Ar age previously reported at 1072±11Ma [Turner G., Huneke, J.C., Podosek, F.A., Wasserburg, G.J., 1971. 40Ar–39Ar ages and cosmic ray exposure ages of Apollo 14 samples. Earth Planet. Sci. Lett. 12, 19–35]. The R-value determined in this study can also be used to intercalibrate FCs if we consider the K/Ar date of 1072Ma as a reference age for Hb3gr. We derive an age of 27.95±0.19Ma (1σ; internal error only) for FCs which is in agreement with the previous determinations. Altogether, this shows that Hb3gr is a suitable standard for 40Ar/39Ar geochronology. [Copyright &y& Elsevier]

Published
2006
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results