Horizon / Plein textes La base de ressources documentaires de l'IRD

IRD

 

Publications des scientifiques de l'IRD

Andujar J., Martel C., Pichavant M., Samaniego Pablo, Scaillet B., Molina I. (2017). Structure of the plumbing system at Tungurahua volcano, Ecuador : insights from phase equilibrium experiments on july-august 2006 eruption products. Journal of Petrology, 58 (7), 1249-1278. ISSN 0022-3530

Accès réservé (Intranet IRD) Demander le PDF

Lien direct chez l'éditeur doi:10.1093/petrology/egx054

Titre
Structure of the plumbing system at Tungurahua volcano, Ecuador : insights from phase equilibrium experiments on july-august 2006 eruption products
Année de publication2017
Type de documentArticle référencé dans le Web of Science WOS:000415097800001
AuteursAndujar J., Martel C., Pichavant M., Samaniego Pablo, Scaillet B., Molina I.
SourceJournal of Petrology, 2017, 58 (7), p. 1249-1278. ISSN 0022-3530
RésuméUnderstanding the plumbing system structure below volcanoes and the storage conditions (temperature, pressure, volatile content and oxygen fugacity) of erupted magmas is of paramount importance for eruption forecasting and understanding of the factors controlling eruptive dynamics. Phase equilibria experiments have been performed on a Tungurahua andesite (Ecuador) to shed light on the magmatic conditions that led to the July-August 2006 eruptions and the parameters that controlled the eruptive dynamics. Crystallization experiments were performed on a representative August 2006 mafic andesite product between 950 and 1025A degrees C, at 100, 200 and 400 MPa and NNO + 1 and NNO + 2 (where NNO is nickel-nickel oxide buffer), and water mole fractions in the fluid (XH2O) from 0 center dot 3 to 1 (water-saturation). Comparison of the natural phenocryst assemblage, proportions and phenocryst compositions with our experimental data indicates that the natural andesite experienced two levels of ponding prior to the eruption. During the first step, the magma was stored at 400 MPa (15-16 km), 1000A degrees C, and contained c. 6 wt % dissolved H2O. In the second step, the magma rose to a confining pressure of 200 MPa (8-10 km), where subsequent cooling (to 975A degrees C) and water-degassing of the magma led to the crystallization of reversely zoned rims on pre-existing phenocrysts. The combination of these processes induced oxidation of the system and overpressure of the reservoir, triggering the July 2006 eruption. The injection of a new, hot, volatile-rich andesitic magma from 15-16 km into the 200 MPa reservoir shortly before the eruption was responsible for the August 2006 explosive event. Our results highlight the complexity of the Tungurahua plumbing system in which different magmatic reservoirs can coexist and interact in time and are the main controlling factors of the eruptive dynamics.
Plan de classementGéophysique interne [066] ; Géologie et formations superficielles [064]
Descr. géo.EQUATEUR ; TUNGURAHUA VOLCAN
LocalisationFonds IRD [F B010071354]
Identifiant IRDfdi:010071354
Lien permanenthttp://www.documentation.ird.fr/hor/fdi:010071354

Export des données

Disponibilité des documents

Télechargment fichier PDF téléchargeable

Lien sur le Web lien chez l'éditeur

Accès réservé en accès réservé

HAL en libre accès sur HAL


Accès aux documents originaux :

Le FDI est labellisé CollEx

Accès direct

Bureau du chercheur

Site de la documentation

Espace intranet IST (accès réservé)

Suivi des publications IRD (accès réservé)

Mentions légales

Services Horizon

Poser une question

Consulter l'aide en ligne

Déposer une publication (accès réservé)

S'abonner au flux RSS

Voir les tableaux chronologiques et thématiques

Centres de documentation

Bondy

Montpellier (centre IRD)

Montpellier (MSE)

Cayenne

Nouméa

Papeete

Abidjan

Dakar

Niamey

Ouagadougou

Tunis

La Paz

Quito