Manioc : Portail | resultats 401 - 420 pour la recherche: éruption

"Atlantide et Martinique", Le Magasin pittoresque
Auteur(s) : Talamo

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Martinique. Ruines de l'église du Fort à Saint-Pierre
Auteur(s) : Symphorien

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Martinique. Saint-Pierre. Mr le Gouverneur sur les ruines de l'ancien théâtre
Auteur(s) : Leboullanger

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Nephelinite lavas at early stage of rift initiation (Hanang volcano, North Tanzanian Divergence)
Auteur(s) : BAUDOUIN, Celine Parat, Fleurice DENIS, Carole Mangasini, Fredrik
Auteurs secondaires : Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Manteau et Interfaces ; Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) University of Dar Es Salaam

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
North Tanzanian Divergence is the first stage of continental break-up of East African Rift (<6 Ma) and is one of the most concentrated areas of carbonatite magmatism on Earth, with singular Oldoinyo Lengai and Kerimasi volcanoes. Hanang volcano is the southernmost volcano in the North Tanzanian Divergence and the earliest stage of rift initiation. Hanang volcano erupted silica-undersaturated alkaline lavas with zoned clinopyroxene, nepheline, andradite-schorlomite, titanite, apatite, and pyrrhotite. Lavas are low MgO-nephelinite with low Mg# and high silica content (Mg# = 22.4–35.2, SiO2 = 44.2–46.7 wt%, respectively), high incompatible element concentrations (e.g. REE, Ba, Sr) and display Nb–Ta fractionation (Nb/Ta = 36–61). Major elements of whole rock are consistent with magmatic differentiation by fractional crystallization from a parental melt with melilititic composition. Although fractional crystallization occurred at 9–12 km and can be considered as an important process leading to nephelinite magma, the complex zonation of cpx (e.g. abrupt change of Mg#, Nb/Ta, and H2O) and trace element patterns of nephelinites recorded magmatic differentiation involving open system with carbonate–silicate immiscibility and primary melilititic melt replenishment. The low water content of clinopyroxene (3–25 ppm wt. H2O) indicates that at least 0.3 wt% H2O was present at depth during carbonate-rich nephelinite crystallization at 340–640 MPa and 1050–1100 °C. Mg-poor nephelinites from Hanang represent an early stage of the evolution path towards carbonatitic magmatism as observed in Oldoinyo Lengai. Paragenesis and geochemistry of Hanang nephelinites require the presence of CO2-rich melilititic liquid in the southern part of North Tanzanian Divergence and carbonate-rich melt percolations after deep partial melting of CO2-rich oxidized mantle source.
ISSN: 0010-7999

hal-01467390
https://hal.archives-ouvertes.fr/hal-01467390
DOI : 10.1007/s00410-016-1273-5

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Saint-Pierre de la Martinique. Les derniers vestiges de la place de la cathédrale
Auteur(s) : L'Harmattan

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Martinique. Saint-Pierre. Vue générale des ruines de la ville
Auteur(s) : Leboullanger

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"Les dernières éruptions de la montagne Pelée", L'Illustration
Auteur(s) : Des Grottes, Eugène

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Martinique. Morne Rouge. Intérieur de l'église après les éruptions du Mont-Pelée
Auteur(s) : Leboullanger

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"Neuf ans après, une ville qui veut ressusciter: Saint-Pierre de la Martinique", L'Illustration, n°3561
Auteur(s) : Dorwling Carter

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Saint-Pierre. Façade de la cathédrale après l'éruption du 08 mai 1902

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Pb, Hf and Nd isotope compositions of the two Reunion volcanoes (Indian Ocean): A tale of two small-scale mantle "blobs"?
Auteur(s) : Bosch, Delphine Blichert-Toft, Janne Moynier, Frédéric Nelson, B. K. Telouk, Philippe Gillot, P. Y. Albarède, Francis
Auteurs secondaires : Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Laboratoire de Sciences de la Terre (LST) ; École normale supérieure - Lyon (ENS Lyon) - Université Claude Bernard Lyon 1 (UCBL) - Institut national des sciences de l'Univers (INSU - CNRS) - Centre National de la Recherche Scientifique (CNRS) Department of Earth and Space Sciences [Seattle] ; University of Washington [Seattle] Institut de Physique du Globe de Paris (IPGP) ; Université Pierre et Marie Curie - Paris 6 (UPMC) - Institut national des sciences de l'Univers (INSU - CNRS) - IPG PARIS - Université Paris Diderot - Paris 7 (UPD7) - Université de la Réunion (UR) - Centre National de la Recherche Scientifique (CNRS)

Éditeur(s) : HAL CCSD Elsevier
Résumé : Pb, Hf, Nd and Sr isotopes of basaltic lavas from the two Reunion Island volcanoes are reported in order to examine the origin of the sources feeding these volcanoes and to detect possible changes through time. Samples, chosen to cover the whole lifetime of the two volcanoes (from 2 Ma to present), yield a chemically restricted (compared to 0113 lavas) but complex distribution. Reunion plume isotopic characteristics have been defined on the basis of the composition of uncontaminated shield-building lavas from the Piton de la Fournaise volcano. The average epsilon(Nd), epsilon(Hf), Sr-87/Sr-86 and Pb-206/Pb-204, Pb-207/Pb-204, and Pb-208/Pb-204 isotope ratios calculated for this component are +4.4, +9.1, 0.70411, 18.97, 15.59 and 39.03, respectively. In Pb-Pb isotope space, each volcano defines a distinct linear trend but slight variation are also detected within the various volcanic sequences. The Piton des Neiges volcano yields a distinct and significantly more scattered isotopic distribution than Piton de la Fournaise for both Pb, Hf and Nd isotope tracers. A principal component analysis of the Pb isotope data from Piton de la Fournaise reveals a major contribution of the C and EM-1 components (with a clear Dupal flavor) as main components for the modem Reunion plume. The same components have been identified for Piton des Neiges but with a stronger participation of a depleted mantle component and a weaker EM-1 contribution. The compositional change of the lavas erupted by the Piton des Neiges and Piton de la Fournaise volcanoes is attributed to the impingement of two small-scale blobs of plume material at the base of the Reunion lithosphere. Compared to other hot-spots worldwide, in particular Hawaii and Kerguelen, magmas beneath Reunion are generated from a considerably more homogeneous, compositionally more primitive plume higher in Pb-206. Although shallow-level contamination processes have been locally detected they did not alter significantly the composition of the plume magmas. This is tentatively attributed to mantle dynamics producing small, high-velocity blobs that ascend rapidly through the lithosphere, and to the lack of a well-developed magma chamber at depth in the lithosphere.
ISSN: 0012-821X

hal-00412196
https://hal.archives-ouvertes.fr/hal-00412196
DOI : 10.1016/j.epsl.2007.11.018

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Subduction initiation and ophiolite crust: new insights from IODP drilling
Auteur(s) : Reagan, Mark K. Pearce, Julian a. Petronotis, Katerina Almeev, Renat R. Avery, Aaron j. Carvallo, C. Chapman, Timothy Christeson, Gail l.
Auteurs secondaires : University of Iowa [Iowa] Cardiff University A&M University, College Station Institut fur Mineralogy, Hannovre Florida State University Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC) ; Muséum National d'Histoire Naturelle (MNHN) - Université Pierre et Marie Curie - Paris 6 (UPMC) - Institut de recherche pour le développement [IRD] : UR206 - Centre National de la Recherche Scientifique (CNRS) University of Sydney University of Texas

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Discovery of a Devonian mafic magmatism on the western border of the Murzuq basin (Saharan metacraton): Paleomagnetic dating and geodynamical implications
Auteur(s) : Derder, M. E. M. Maouche, S. Liegeois, J. P. Henry, B. Amenna, M. Ouabadi, A. Bellon, H. BRUGUIER, Olivier
Auteurs secondaires : CRAAG, Alger Royal Museum for Central Africa [Tervuren] (RMCA) Institut de Physique du Globe de Paris (IPGP) ; Institut national des sciences de l'Univers (INSU - CNRS) - IPG PARIS - Université Paris Diderot - Paris 7 (UPD7) - Université de la Réunion (UR) - Centre National de la Recherche Scientifique (CNRS) USTBH, Alger Domaines Océaniques (LDO) ; Centre National de la Recherche Scientifique (CNRS) - Institut d'écologie et environnement - Observatoire des Sciences de l'Univers - Université de Brest (UBO) - Institut national des sciences de l'Univers (INSU - CNRS) Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Dynamique de la Lithosphere ; Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Office National du Parc Culturel du Tassili N'ajjer

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Intraplate deformation is most often linked to major stress applied on plate margins. When such intraplate events are accompanied by magmatism, the use of several dating methods integrated within a multidisciplinary approach can bring constraints on the age, nature and source mobilized for generating the magma and in turn on the nature of the intraplate deformation. This study focuses on the large gabbro Arrikine sill (35 km in extension) emplaced within the Silurian sediments of the western margin of the Murzuq cratonic basin in southeastern Algeria. Its emplacement is dated during the early Devonian (415-400 Ma) through the determination of a reliable paleomagnetic pole by comparison with the Gondwana Apparent Polar Wander Path (APWP). This age can be correlated with deep phreatic eruptions before Pragian time thought to be at the origin of sand injections and associated circular structures in Algeria and Libya. For the sill, the K–Ar age of 325.6 ± 7.7 Ma is related to a K-rich aplitic phase that has K-enriched by more than 20% the Devonian gabbro. Laser-ICP-MS U–Pb method dates only inherited zircons mostly at c. 2030 Ma with additional ages at c. 2700 Ma and younger ones in the 766-598 Ma age range. The Arrikine sill is a high-Ti alkaline gabbro having the geochemical composition of a hawaiite akin to several intraplate continental and oceanic provinces, including the contemporaneous Aïr ring complexes province in Niger, but also to the Mauna Loa volcano in Hawaii. This peculiar composition akin to that of the contemporaneous Aïr province is in agreement with a lower Devonian age for the Arrikine sill.The lower Devonian Arrikine sill emplacement is related to a “Caledonian” transtensive reactivation of the western metacratonic boundary of the Murzuq craton. This event also generated in the Saharan platform the so-called “Caledonian unconformity” of regional extension, the Aïr ring complexes and magmatic rocks that produced sand injections. It could be related to rifting of the Hun terranes that occurred at the plate margin to the north (Stampfli and Borel, 2002, Blackey, 2008 and references therein). The mid-Carboniferous (c. 326 Ma) reactivation corresponds to Variscan compression on NW Africa generating aplitic fluids, but also to the major “Hercynian unconformity” of regional extension. The generation of the Arrikine magma is attributed to partial melting through adiabatic pressure release of uprising asthenosphere along tectonically reactivated mega-shear zones, here bordering the relictual Murzuq craton enclosed in the Saharan metacraton.
ISSN: 0899-5362

hal-01306637
https://hal.archives-ouvertes.fr/hal-01306637
DOI : 10.1016/j.jafrearsci.2015.11.019

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Saint-Pierre. Façade d'un bâtiment en ruines après l'éruption du 08 mai 1902

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Vue générale de Saint-Pierre (Martinique), après la catastrophe du 8 mai 1902
Auteur(s) : Neurdein et Cie

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Saint-Pierre de la Martinique. Après mai 1902

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Silicate liquid-carbonatite liquid transition along the melting curve of model, vapor-saturated peridotite in the system CaO-MgO-Al2O3-SiO2-CO2 from 1.1 to 2 GPa
Auteur(s) : Keshav, Shantanu Gudfinnsson, Gudmundur H.
Auteurs secondaires : Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Iceland GeoSurvey, Reykjavik ; Université du Québec

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Martinique. Ruines de la cathédrale de Saint-Pierre
Auteur(s) : Russon

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Martinique. Saint-Pierre. Vue générale des ruines
Auteur(s) : Leboullanger

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Ruines du phare place Bertin à Saint-Pierre, Martinique
Auteur(s) : Compagnie des Antilles

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