Ascension et dégazage des magmas basaltiques : application aux volcans d'Islande et de la Chaîne des Puys (France)

Basaltic magmas exhibit rare explosive eruptions, whose physical properties remain poorly understood. This study reveals that subplinian and phreatomagmatic eruptions from the Grímsvötn volcano (Iceland) and the Chaîne des Puys (France) display distinct volatile concentrations and degassing behaviors, with subplinian eruptions showing higher volatile emissions due to greater gas exsolution. Thermobarometric analysis indicates that the Grímsvötn's shallow magma chamber acts as a reservoir for exsolved gases, while the Chaîne des Puys' eruption suggests a deeper magmatic contribution, challenging the notion of a mantle hotspot. Experimental data confirm clinopyroxene-liquid thermobarometry as a reliable method for estimating crystallization pressures and temperatures in tholeiitic magmas.

Haddadi, B. Ascension et dégazage des magmas basaltiques : application aux volcans d’Islande et de la Chaîne des Puys (France). https://doi.org/10.70675/b6ff6e5ezf77dz48bezb01azb7dc1e7e7fdd