Séminaire ISTerre

---

Dynamics of magma ascent and magma chambers formation in the Earth crust

vendredi 9 décembre 2022 - 10h00

Oleg Melnik  - Lomonosov Moscow State University
--- 
I will consider two models related to magma ascent and deposition in the Earth crust. A model of volatile rich silicic dike propagation with account of multiple volatile species (water+CO2), crystallization and heat exchange during the ascent. Depending on the water+CO2 ratio of the source magma the dike can reach the surface or can be arrested at shallow depth and solidify. Simulation show surprisingly high ascent rates for rhyolitic magmas at depth due to significantly higher buoyancy of the magma in respect to volatile pour basalts. A model of a growth of magma chamber by periodic injection of dikes and sills into country rocks accounts for heat transfer, latent heat of crystallization/melting, phase diagrams and eruptions. The model is linked to zircon crystals diffusive growth that allows interpretation of magmatic processes based on measurable ages, isotopes, and trace element partitioning.

---

Equipe organisatrice : Géophysique des volcans & Géothermie

Salle Paul Gidon, Bâtiment Belledonnes, 73376 Le Bourget-du-Lac

Informations de visio :

https://univ-grenoble-alpes-fr.zoom.us/j/97609232320?pwd=RnFqVXFQZldZTVhYNVA2ZlZiMVpFQT09