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	Provedor de dados ArchiMer (2) Autor Burdloff, D (1) Cortijo, E (1) Doucet, S (1) Duprat, J (1) Giret, A (1) Grousset, Fe (1) Herve, L (1) Huon, S (1) Richter, T (1) Scoates, Js (1) Weber, O (1) Weis, D (1) Mais... Palavra-chave Radiogenic isotope geochemistry (2) Climate and interannual variability (1) Climate dynamics (1) Composition of the mantle (1) Hf-Pb-Sr-Nd isotopes (1) Igneous petrology (1) Indian Ocean (1) Kerguelen Archipelago (1) Major and trace element geochemistry (1) Mantle plume components (1) Picrites (1) Mais... Tipo do documento Text (2) Ano 2005 (1) 2001 (1) País France (2) Idioma Inglês (2)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 2 Primeira ... 1 ... Última Zooming in on Heinrich layers ArchiMer Grousset, Fe; Cortijo, E; Huon, S; Herve, L; Richter, T; Burdloff, D; Duprat, J; Weber, O. Theories explaining the origin of the abrupt, massive discharges of ice-rafted detritus (IRD) into the glacial North Atlantic (the Heinrich layers (HLs)) generally point to the Laurentide ice sheet as the sole source of these events, until it was found that the IRDs also originated from Icelandic and European ice sheets [Bond and Lotti, 1995; Snoeckx er al., 1999; Grousset et al., 2000]. This apparent contradiction must be reconciled as it raises fundamental questions about the mechanism(s) of HL origin. We have analyzed two similar to 12 cm thick HLs in an ultrahigh-resolution mode (1-2 century intervals) in a mid-Atlantic ridge piston core. The delta O-18 record (N. pachyderma left coiling) reveals strong excursions induced by the melting of the... Tipo: Text Palavras-chave: Climate and interannual variability; Climate dynamics; Radiogenic isotope geochemistry. Ano: 2001 URL: https://archimer.ifremer.fr/doc/00221/33190/31786.pdf 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 Registros recuperados: 2 Primeira ... 1 ... Última

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