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	Provedor de dados ArchiMer (2) Autor Abbott, P. M. (1) Bourne, A. J. (1) Davies, S. M. (1) Doucet, S (1) Giret, A (1) Pearce, N. J. G. (1) Purcell, C. S. (1) Scoates, Js (1) Scourse, J. D. (1) Weis, D (1) Mais... Palavra-chave Major and trace element geochemistry (2) Composition of the mantle (1) Hf-Pb-Sr-Nd isotopes (1) Iceland (1) Igneous petrology (1) Indian Ocean (1) Isochrons (1) Kerguelen Archipelago (1) Mantle plume components (1) Palaeoclimate synchronisation (1) Picrites (1) Radiogenic isotope geochemistry (1) Tephrochronology (1) Volcanic ash (1) Mais... Tipo do documento Text (2) Ano 2016 (1) 2005 (1) País France (2) Idioma Inglês (2)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 2 Primeira ... 1 ... Última Constraining the components of the Kerguelen mantle plume: A Hf-Pb-Sr-Nd isotopic study of picrites and high-MgO basalts from the Kerguelen Archipelago ArchiMer Doucet, S; Scoates, Js; Weis, D; Giret, A. We report geochemical and Hf-Pb-Sr-Nd isotopic analyses of a suite of picrites and associated high-MgO volcanic rocks (6-17 wt.% MgO) from the Kerguelen Archipelago, which are rare compared to other oceanic islands, to better constrain the nature and the origin of components present in the Kerguelen mantle plume source. The Sr and Nd isotopic compositions of the transitional to mildly alkalic picrites and high-MgO basalts closely match those of the 24 Ma mildly alkalic basalts from the Courbet Peninsula, whose compositions are considered to reflect the present geochemical expression of the enriched component of the Kerguelen mantle plume. However, linear trends in Pb isotopic compositions in the studied samples reflect involvement of a component with lower... Tipo: Text Palavras-chave: Kerguelen Archipelago; Picrites; Hf-Pb-Sr-Nd isotopes; Mantle plume components; Composition of the mantle; Radiogenic isotope geochemistry; Major and trace element geochemistry; Igneous petrology; Indian Ocean. Ano: 2005 URL: https://archimer.ifremer.fr/doc/00230/34086/32519.pdf Last glacial period cryptotephra deposits in an eastern North Atlantic marine sequence: Exploring linkages to the Greenland ice-cores ArchiMer Abbott, P. M.; Bourne, A. J.; Purcell, C. S.; Davies, S. M.; Scourse, J. D.; Pearce, N. J. G.. The establishment of a tephra framework for the Greenland ice-cores spanning the last glacial period, particularly between 25 and 45 Ica b2k, provides strong potential for precisely correlating other palaeoclimatic records to these key archives. Tephra-based synchronisation allows the relative timing of past climatic changes recorded within different depositional environments and potential causal mechanisms to be assessed. Recent studies of North Atlantic marine records have demonstrated the potential of tracing cryptotephra horizons in these sequences and the development of protocols now allows a careful assessment of the isochronous nature of such horizons. Here we report on tephrochronological investigations of a marine sequence retrieved from the Goban... Tipo: Text Palavras-chave: Tephrochronology; Palaeoclimate synchronisation; Volcanic ash; Isochrons; Iceland; Major and trace element geochemistry. Ano: 2016 URL: https://archimer.ifremer.fr/doc/00421/53274/83380.pdf Registros recuperados: 2 Primeira ... 1 ... Última

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