Viscosity of silicate melts from the active submarine volcanic chain of Mayotte

International audienceFollowing an unprecedented seismic activity that started in May 2018, a new volcanic edifice, now called Mont Fani Maoré, was constructed on the ocean floor 50 km east of the island of Mayotte (Indian Ocean). This volcano is the latest addition to a volcanic chain characterized by an alkaline basanite-to-phonolite magmatic differentiation trend. Here, we performed viscosity measurements on five silicate melts representative of the East-Mayotte Volcanic Chain compositional trend: two basanites from Mont Fani Maoré, one tephri-phonolite and two phonolites from different parts of the volcanic chain. A concentric cylinder viscometer was employed at super-liquidus conditions between 1500 K and 1855 K and a creep apparatus was used for measuring the viscosity of the undercooled melts close to the glass transition temperature. At super-liquidus temperatures, basanites have the lowest viscosity (0.11-0.99 log10 Pa⸱s), phonolites the highest (0.91-3.89 log10 Pa⸱s), while the viscosity of the tephr

Viscosity of silicate melts from the active submarine volcanic chain of Mayotte

International audienceFollowing an unprecedented seismic activity that started in May 2018, a new volcanic edifice, now called Mont Fani Maoré, was constructed on the ocean floor 50 km east of the island of Mayotte (Indian Ocean). This volcano is the latest addition to a volcanic chain characterized by an alkaline basanite-to-phonolite magmatic differentiation trend. Here, we performed viscosity measurements on five silicate melts representative of the East-Mayotte Volcanic Chain compositional trend: two basanites from Mont Fani Maoré, one tephri-phonolite and two phonolites from different parts of the volcanic chain. A concentric cylinder viscometer was employed at super-liquidus conditions between 1500 K and 1855 K and a creep apparatus was used for measuring the viscosity of the undercooled melts close to the glass transition temperature. At super-liquidus temperatures, basanites have the lowest viscosity (0.11-0.99 log10 Pa⸱s), phonolites the highest (0.91-3.89 log10 Pa⸱s), while the viscosity of the tephr