EGU22-10766, updated on 04 Jan 2023
EGU General Assembly 2022
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Structure of a new submarine volcano and magmatic phases to the East of Mayotte, in the Comoros Archipelago, Indian Ocean.

Charles Masquelet1, Sylvie Leroy1, Matthias Delescluse2, Nicolas Chamot-Rooke2, Isabelle Thinon3, Anne Lemoine3, Dieter Franke4, Louise Watremez5, Philippe Werner6, Daniel Sauter6, and the SISMAORE team*
Charles Masquelet et al.
  • 1Sorbonne Université, CNRS, Institut des Sciences de la Terre de Paris (ISTeP), Paris, France (
  • 2Laboratoire de Géologie de l’École Normale Supérieure (ENS), CNRS, Paris, France (
  • 3Bureau de Recherches Géologiques et Minières (BRGM), Orléans, France (
  • 4Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Geozentrum Hannover, Deutschland (
  • 5Université de Lille, CNRS, Université Littoral Côte d’Opale, IRD, UMR 8187 – LOG – Laboratoire d’Océanologie et de Géosciences, Lille, France (
  • 6Institut Terre et Environnement de Strasbourg (ITES), CNRS Université de Strasbourg, Strasbourg, France (
  • *A full list of authors appears at the end of the abstract

50 km East of Mayotte Island (North Mozambique Channel; Comoros Archipelago), a submarine volcanic edifice formed during the first year of a seismo-volcanic crisis, between May 2018 and May 2019. Thanks to the French ANR Project COYOTES and the SISMAORE oceanographic cruise (2021), a multichannel seismic profile gives the first in-depth image of the new East-Mayotte volcano and its surrounding volcanic area. The seismic interpretation reveals that several distinct magmatic phases affected the area. The new volcano is built on a ~150 m thick sedimentary layer. Beneath this sedimentary layer, we found a major volcanic layer, ~2.5 km thick, which extends ~91 km to the south and ~33 km to the north of the newly formed submarine volcano. This volcanic unit is composed of multiple seismic facies that may indicate distinct successive volcanic phases. We interpret this major volcanic layer as part of the Mayotte volcanic edifice, with the presence of a complex magmatic feeder system underneath. We observe a ~2.2-2.5 km thick sedimentary cover between the main volcanic layer, below the new volcano, and the top of the crust. We tentatively identified the top-Oligocene seismic horizon (~23 Ma) well above the main volcanic layer, and assuming a constant sedimentation rate we estimate the onset of the volcanism at Mayotte Island at 28 Ma.


How to cite: Masquelet, C., Leroy, S., Delescluse, M., Chamot-Rooke, N., Thinon, I., Lemoine, A., Franke, D., Watremez, L., Werner, P., and Sauter, D. and the SISMAORE team: Structure of a new submarine volcano and magmatic phases to the East of Mayotte, in the Comoros Archipelago, Indian Ocean., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10766,, 2022.