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Central southern Iceland is one of the main outlets of the Icelandic Ice Sheet where a MIS 5e sedimentary complex, the Ranga Formation, is extensively observed below the last deglaciation terminal moraines. Sedimentary facies demonstrate that the Ranga Formation is mostly tidal, up to 215 m (transgression I) and 168 m (transgression II) in altitude. The first highstand reworks a thick tephra from the Grimsvotn volcano, known in marine cores as 5e low/Bas-IV and positioned at ca. 127 Ka BP, the Eemian thermal optimum. This formation is related to a rapid deglaciation followed by two marine transgressions marked by the development of extended mud flats, which were separated by a complex regression phase, associated with loess deposition, ca. 9 Ka in duration. Palaeo jokulhlaups, basaltic flows, and tephra fallouts from the Hekla and Grimsvotn volcanoes affected the sedimentation. The Ranga Formation yields one of the first continuous and complete estuarine records of the Eemian interglacial in Iceland and probably for most of the northern terrestrial Atlantic. This estuarine infill records the distal signature of a complex glacial advance within the last interglacial, already well identified in northern and central Iceland. The glacial advance is attributed to the intra-Eemian cooling events (Greenland GS 26 or marine cold events M-C25-C26). It is followed by a warming and a glacial retreat corresponding to the Greenland GI 25 event. This formation allows, in connection with the timing of recognized volcanic periods, a better insight of the interconnections between sea-level, regional glacial extent, and Northern Hemisphere marine and ice core climatic records. Le centre de l'Islande méridionale est un des exutoires de la calotte glaciaire islandaise. Un complexe sédimentaire du MIS 5e, la Formation Rangá, y est préservé sous les moraines terminales de la dernière déglaciation. Les faciès sédimentaires de cette formation sont tidaux et enregistrent deux hauts niveaux marins successifs jusqu'à 215 m (transgression I) et 168 m (transgression II) d'altitude. Lors de l'optimum thermique éémien vers 127 Ka BP, le premier haut niveau a remanié un épais téphra du volcan Grimsvötn, le 5e Bas-IV inférieur des carottes marines. La mise en place de cette formation est liée à une déglaciation rapide suivie par le développement de vasières étendues lors des hauts niveaux littoraux; une phase de régression complexe avec dépôt loessique d'une durée d'environ 9 k.a. les sépare. Des paléo-jökulhlaups, des coulées basaltiques et des téphras de l'Hekla et de Grimsvötn sont enregistrés. Cette formation constitue l'un des premiers enregistrement estuariens complets de l'Éémien en Islande et pour l'Atlantique Nord. Elle conserve la signature distale d'une avancée glaciaire complexe durant le dernier interglaciaire, déjà bien établie dans le nord et le centre de l'Islande. Cette avancée glaciaire est attribuée aux refroidissements intraéémiens (GS 26 au Groenland ou refroidissements marins M-C25-C26). Elle est suivie par un réchauffement et une déglaciation corrélée à l'événement GI 25 du Groenland. Cette formation, en couplage avec des corrélations téphrostratigaphiques, permet une meilleure compréhension des interconnexions entre le niveau marin, l'extension régionale des calottes glaciaires et l'enregistrement climatique extrait des carottes marines et de glace pour l'hémisphère nord. [Traduit par la Rédaction], Introduction Very few coastal sequences record the last interglacial close to the 60[degrees]N latitude. Last interglacial (MIS 5) sediments have been described at Fjosanger in central Norway (60[degrees]N, Mangerud et [...]

Amphibole [+ or -] apatite-bearing lherzolite xenoliths from Yemen have Sr, Nd, and Pb isotope ratios that are the same as those of Oligocene flood and Quaternary intraplate basalts in Yemen, and also the Afar plume, which is genetically linked with this volcanism. The xenoliths have mineral, chemical, and isotopic characteristics consistent with enrichment of shallow mantle by carbonatitic melts and hydrous fluids from the Afar plume during or shortly after Oligocene flood volcanism. Separation of carbonatitic melts and hydrons fluids from mantle plumes may affect the composition of erupted flood basalts and is consistent with an origin of such plumes by recycling of oceanic lithosphere. Mantle plumes appear to have volatile fluxes that are large enough to affect solidus temperatures, both within plumes and the overlying lithospheric mantle, during the generation of large igneous provinces. The fertile lithosphere formed by plume-derived melts and fluids is an important potential source for intraplate volcanism that can be exploited by melting during later extension or erosional unloading of the lithosphere.