The Shallow Plumbing System of Piton de la Fournaise Volcano (La Reunion Island, Indian Ocean) Revealed by the Major 2007 Caldera-Forming Eruption

A major 2007 caldera-forming eruption at Piton de la Fournaise (La Réunion Island) revealed the volcano's shallow plumbing system, showing that a deep magma input triggered significant volcanic activity. The eruption expelled the largest recorded volume of magma in centuries (210 Mm³), with distinct geochemical and petrological signatures across eruptive phases. Pre-collapse magmas exhibited unique isotopic compositions, while post-collapse oceanite lavas dominated the erupted volume. The study proposes a new model where shallow sills host variable degassing, cooling, and crystallization, with deeper, hotter basaltic magma injections driving lateral draining and flank instability. Multistep ascent and water degassing were identified as key processes in fast magma crystallization at shallow depths.

Di Muro, A., Metrich, N., Vergani, D., Rosi, M., Armienti, P., Fougeroux, T., Deloule, E., Arienzo, I., & Civetta, L. (2014). The Shallow Plumbing System of Piton de la Fournaise Volcano (La Reunion Island, Indian Ocean) Revealed by the Major 2007 Caldera-Forming Eruption. Journal of Petrology, 55(7), 1287–1315. https://doi.org/10.1093/petrology/egu025