EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Volcanism and tectonics unveiled in the Comoros Archipelago between Africa and Madagascar

Isabelle Thinon1, Anne Lemoine1, Sylvie Leroy2, Fabien Paquet1, Carole Berthod3,4, Sébastien Zaragosi5, Vincent Famin6, Nathalie Feuillet3, Pierre Boymond3, Charles Masquelet2, Anais Rusquet6,3, Nicolas Mercury1,7, and the SISMAORE and COYOTES teams*
Isabelle Thinon et al.
  • 1BRGM, DGR-GBS, Orléans, France (
  • 2Sorbonne Universite, CNRS-INSU, Institut des Sciences de la Terre de Paris, ISTeP, Paris, France
  • 3Universite de Paris, Institut de physique du globe de Paris, CNRS, UMR 7154; F-75005 Paris, France
  • 4Universite Clermont Auvergne, CNRS, IRD, OPGC, LaboratoireMagmas et Volcans, 6 avenue Blaise Pascal, 63178 Aubiere, France
  • 5Universite de Bordeaux, CNRS, EPOC, EPHE, UMR 5805; F-33600 Pessac, France
  • 6Universite de La Reunion, Laboratoire GeoSciences Reunion, F-97744 Saint-Denis, France
  • 7Institut Terre et Environnement de Strasbourg (ITES), Universite de Strasbourg CNRS UMR 7063; 5 rue Descartes, FR-67084 Strasbourg, France
  • *A full list of authors appears at the end of the abstract

Geophysical and geological data acquired during the 2020–2021 SISMAORE oceanographic cruise reveal a corridor of recent volcanic and tectonic features 200 km wide and 600 km long within and north of Comoros Archipelago in the North Mozambique Channel. More than 2200 submarine volcanic edifices, comparable to the Fani Maoré volcano, have been identified. Most of them are distributed according to two large submarine tectonic-volcanic fields: the N’Drounde province oriented N160°E north of Grande-Comore Island, and the Mwezi province oriented N130°E north of Anjouan and Mayotte Islands. The presence of popping basaltic rocks sampled in the Mwezi suggests post-Pleistocene volcanic activity. The geometry and distribution of recent structures observed on the seafloor are consistent with a current regional dextral transtensional context. Their orientations change progressively from west to east (∼N160°E, ∼N130°E, ∼EW). In the western part, the volcanism could be influenced by the pre-existing structural fabric of the Mesozoic crust. The wide tectono-volcanic corridor underlines the incipient Somalia–Lwandle dextral lithospheric plate boundary between the East-African Rift System and Madagascar. For details see Thinon et al. (2022;  doi 10.5802/crgeos.159).


P. Bachèlery; J. Bernard; J. Bignon; S. Bujan; A. Canva; N. Chamot-Rooke; V. Clouard; E. Dassie; M. Delescluse; C. Doubre; D. Franke; E. Jacques; S.J. Jorry; L. Michon; V. Roche; F. Rolandone; C. Scalabrin; D. Sauter; J. Van der Woerd; L. Watremez; S. Ali; A. H. Sitti Allaouia ; C. Deplus; S. Rad; L. Sadeski

How to cite: Thinon, I., Lemoine, A., Leroy, S., Paquet, F., Berthod, C., Zaragosi, S., Famin, V., Feuillet, N., Boymond, P., Masquelet, C., Rusquet, A., and Mercury, N. and the SISMAORE and COYOTES teams: Volcanism and tectonics unveiled in the Comoros Archipelago between Africa and Madagascar, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-5046,, 2023.