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Séminaire internes 2018-2019

Contact : Guillaume Paris (gparis@crpg.cnrs-nancy.fr)

- 17 septembre 2018 : Céline Baudouin - Alkaline Volcanism associated with early stage of rifting : origin, differentiation & trace element partitioning

East African Rift exposes different stages of extension, from early stage rifting in Tanzania (Natron & Manyara basin) to oceanic accretion in Afar (Ethiopia). Due to its location and tectonic setting, Tanzanian volcanoes offers the opportunity to study the earliest stage of rift initiation and to constrain the origin of alkaline-CO2-rich magmas and magmatic evolution of the silica-undersaturated melts as well as associated carbonatitic magmatism

- 24 septembre 2018 : Marine Boulanger - Melt migration and interactions in the lower oceanic crust : insights from Atlantis Bank interlayered series at IODP Hole U1473A (Southwest Indian Ridge)

Oceanic crust accretion processes at slow-spreading ridges are yet insufficiently constrained, especially for the lower crust. One of the key challenges is to understand how melts migrate through the lower crust and in what extent they interact with surrounding lithologies. For that purpose we studied a cumulate portion of lower crust exhumed at the Atlantis Bank Oceanic Core Complex, and sampled by drilling during IODP Exp. 360. The cumulate olivine gabbro presents intense layering which origins gave us new insights on magma migration, emplacement, crystallization and interaction processes. We found that the overall sequence displays melt/rock reactions or homogenization overprints developing at all stages of formation of the cumulate. This suggests that interaction processes, and thus the migration of melts in this heterogeneous environment are two of the prevailing key parameters controlling the crust and eruptive material composition.

- 15 octobre 2018 : Guillaume Florin

- 5 novembre 2018 : Camille Litty

- 12 novembre 2018 : Apolline Mariotti

- 19 novembre 2018 : Carlotta Ferrando

publié mercredi 14 août 2013