Articles | Volume 37, issue 5
https://doi.org/10.5194/ejm-37-639-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/ejm-37-639-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
01 Oct 2025
Research article |
| 01 Oct 2025
| 01 Oct 2025
Origin and evolution of the Variscan Léon eclogites: insights from zircon and garnet petrochronology
Lorraine Tual
CORRESPONDING AUTHOR
Geo-Ocean, Univ. Brest, CNRS, Ifremer UMR6538, 29280 Plouzané, France
Christine Authemayou
Geo-Ocean, Univ. Brest, CNRS, Ifremer UMR6538, 29280 Plouzané, France
Caroline Lotout
Laboratoire Magmas et Volcans, Université Clermont Auvergne, CNRS, IRD, OPGC, 63000 Clermont-Ferrand, France
Centre de Recherche Pétrologiques et Géochimiques, Université de Lorraine, CNRS, 54000 Nancy, France
Matthijs A. Smit
Department of Earth, Ocean & Atmospheric Sciences, University of British Columbia, Vancouver V6T 1Z4, Canada
Department of Geosciences, Swedish Museum of Natural History, 104 05 Stockholm, Sweden
Kira Musiyachenko
Department of Earth, Ocean & Atmospheric Sciences, University of British Columbia, Vancouver V6T 1Z4, Canada
Denise Bussien Grosjean
Direction de L'environnement Industriel, Urbain Et Rural, Direction Générale de L'environnement, Etat de Vaud, Chemin Des Boveresses 155, 1066 Épalinges, Switzerland
Ellen Kooijman
Department of Geosciences, Swedish Museum of Natural History, 104 05 Stockholm, Sweden
Emilie Bruand
Geo-Ocean, Univ. Brest, CNRS, Ifremer UMR6538, 29280 Plouzané, France
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Beatrice Celata, Ferdinando Bosi, Kira A. Musiyachenko, Andrey V. Korsakov, and Giovanni B. Andreozzi
Eur. J. Mineral., 36, 797–811, https://doi.org/10.5194/ejm-36-797-2024, https://doi.org/10.5194/ejm-36-797-2024, 2024
Short summary
Short summary
The discovery of the K-dominant tourmaline maruyamaite with microdiamond inclusions suggested its ultrahigh-pressure formation. We analyzed the role of K in the tourmaline structure, with a special focus on its stability. High pressure is necessary to squeeze the large cation K+ in the stiff framework of tourmaline, although K is the underdog component if Na+ is present in the mineralizing fluid. K-tourmaline is stable at high pressure, overcoming the stereotype of a mere crustal component.
Ross J. Angel, Mattia L. Mazzucchelli, Kira A. Musiyachenko, Fabrizio Nestola, and Matteo Alvaro
Eur. J. Mineral., 35, 461–478, https://doi.org/10.5194/ejm-35-461-2023, https://doi.org/10.5194/ejm-35-461-2023, 2023
Short summary
Short summary
We have developed the thermodynamic theory of the properties of inclusions consisting of more than one phase, including inclusions containing solids plus a fluid. We present a software utility that enables for the first time the entrapment conditions of multiphase inclusions to be determined from the measurement of their internal pressure when that is measured in a laboratory.
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Short summary
The Léon region in France offers a window into the dramatic geological processes that shaped continents. Studying ancient rocks called eclogite, we uncovered a history of magma generation, deep burial and rapid crustal movement between 390 million and 300 million years ago. The area was shaped by subduction dynamics, where shifting tectonic plates stretched and compressed the crust. These findings help us understand how ancient geological processes continue to influence the Earth’s surface today.
The Léon region in France offers a window into the dramatic geological processes that shaped...
