Geochemical characteristics of the La Réunion mantle plume source inferred from olivine-hosted melt inclusions from the adventive cones of Piton de la Fournaise volcano (La Réunion Island) - Université Clermont Auvergne Accéder directement au contenu
Article Dans Une Revue Contributions to Mineralogy and Petrology Année : 2017

Geochemical characteristics of the La Réunion mantle plume source inferred from olivine-hosted melt inclusions from the adventive cones of Piton de la Fournaise volcano (La Réunion Island)

Marina Valer
  • Fonction : Auteur
  • PersonId : 783947
  • IdRef : 203932382
Pierre Schiano
Patrick Bachèlery

Résumé

Major and trace element compositions were obtained for bulk rocks and melt inclusions hosted in olivine crystals (Fo > 85) from the adventive cones of the Piton de La Fournaise volcano (La Réunion Island). Ratios of highly incompatible trace elements for these magmas are used to identify the nature of the La Réunion mantle plume source. Although adventive cone lavas display unusual major ele - ment compositions compared to the historical lavas of the volcano (e.g., lower CaO/Al 2 O 3 ), trace element data suggest that the magmas emitted by the adventive cones originate from a common chemical source. This source may corre - spond to either a homogeneous mixed source of different mantle components or a near-primitive less-differentiated mantle source. The melt inclusions display ratios of highly incompatible elements (e.g., Th/La, Nb/La) which are simi - lar to primitive mantle values, and lower Nb/U ratios com - pared to most oceanic basalts. These results and previous isotopic and trace element data suggest that La Réunion plume samples a source which is intermediate between a primitive-like mantle domain and a slightly depleted one almost unaffected by the recycling processes. This source could have originated from early depletion of the primitive mantle. Assuming a depletion 4.45 Gyr ago, ~10% melting of this slightly depleted source could explain the enriched trace element concentrations of the melt inclusions
Fichier non déposé

Dates et versions

hal-01709115 , version 1 (14-02-2018)

Identifiants

Citer

Marina Valer, Pierre Schiano, Patrick Bachèlery. Geochemical characteristics of the La Réunion mantle plume source inferred from olivine-hosted melt inclusions from the adventive cones of Piton de la Fournaise volcano (La Réunion Island). Contributions to Mineralogy and Petrology, 2017, 172 (9), ⟨10.1007/s00410-017-1397-2⟩. ⟨hal-01709115⟩
99 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More