The TIMEleSS project aims at studying interfaces in the Earth’s mantle combining observations from seismology, mineral physics experiments, microstructures, and wave propagation modeling. It is supported through a bilateral grant, from the ANR in France and the DFG in Germany. The project is led by Sébastien Merkel and Nadège Hilairet at the Université de Lille, Christine Thomas and Carmen Sanchez-Valle from the Westfälische Wilhelms-Universität, Münster, and Sergio Speziale from the Deutsche GeoForschungsZentrum, Potsdam.

Project launch: March 2018
Duration: 36 months, extended until December 2022
Total ANR-DFG funding: 700 000 €

The active research period of TIMEleSS is now over, but we are still working on our datasets and publications so stay tuned for more!

Latest news

First official release of the TIMEleSS-tools and first publication from outside users

19 March 2023 | Posted in Outreach, TIMEleSS news

The TIMEleSS-tools were developed in the course of the TIMEleSS project to streamline the processing of multigrain crystallography data from diamond anvil cell experiments. They were actively developed in the course of the project, guided by our needs for data processing, and used in all TIMEleSS publications involving multigrain X-ray diffraction. They are a set of python programs, open-source, under the terms of the GNU GENERAL PUBLIC LICENSE, Version 2, and part of the more general FABLE-3DXRD project.

After years of development, we finally reach the time for a 1.0.0 release. TIMEleSS-tools were uploaded to PyPI and will now be easily installable on any python distribution, by simply typing those three magical words pip install timeless-tools. The latest and most up-to-date version will remain at our TIMEleSS-tools github homepage, but this release is easier to install for starting users.

This official release also come with our first user publication! Robin Fréville, Agnès Dewaele, and co-authors published a Physical Review B paper on a Comparison between mechanisms and microstructures of α−γ, γ−ε, and α−ε−α phase transitions in iron on March 14, 2023. It is the first non-TIMEleSS published paper that relies on the TIMEleSS-tools. Congratulations to all!

New publication in Earth and Planetary Science Letters

3 February 2023 | Posted in Publications, TIMEleSS news

Gay et al, Transformation microstructures in pyrolite under stress: Implications for anisotropy in subducting slabs below the 660 km discontinuity (2023) Earth and Planetary Science LettersNew year, and new publication for the TIMEleSS team! Former timeless PhD student Jeff Gay is the first author of Transformation microstructures in pyrolite under stress: Implications for anisotropy in subducting slabs below the 660 km discontinuity, published in the February 15, 2023, issue of Earth and Planetary Science Letters. The publication is a result of a collaboration between partners at the Université de Lille (J. Gay, E. Ledoux, J. Chantel, S. Merkel), WWU Münster (N. Krug, C. Sanchez-Valle) with measurements at the Deutsches Elektronen-Synchrotron (A. Pakhomova, H.-P. Liermann).

The ‘660’ discontinuity marks the boundary between the upper and lower mantle and is located 660 km below our feet. The is discontinuity often associated with a phase transitions in pyrolite, a model rock composition for the Earth’s mantle. In addition, there are ubiquitous reports of seismic anisotropy below the ‘660’ which are difficult to explain from a mineralogical point of view.

In this study, we implement multigrain crystallography X-ray diffraction in the laser-heated diamond anvil cell in order to track microstructures induced by phase transitions at the pressure and temperature conditions of the discontinuity, around 24 GPa and 1900 K. Before the onset of transformation, pyrolite minerals such as garnet and ringwoodite are isotropic and do not contribute to seismic anisotropy.  After the transformation, bridgmanite, the most abundant mineral in the Earth, displays a strong preferred orientation, which we attribute to growth under stress. Other minerals such as davemaoite and ferropericlase are also considered.

The results are used to model anisotropy in a subducting slab, with a prediction of no anisotropy above the ‘660’ and up to 1.28% (0.08 km/s) shear wave splitting below the ‘660’ and provide details on how detailed wave forms can be used to understand the geometry of stress at those depths.

PhD Thesis Defence for Jeffrey Gay

24 November 2022 | Posted in Activities, People news, PhD Theses, Special Events, Student events, TIMEleSS news

PhD Thesis Defense, Jeffrey Gay, Nov 2022A new PhD defense for the TIMEleSS project!

On Nov 24th, 2022, Jeffrey Gay defended his thesis entitled Microstructures and anisotropy of pyrolite in the Earth’s lower mantle: insights from high pressure/temperature deformation and phase transformation experiments at the Université de Lille.

The PhD committee was composed of

  • Motohiko Murakami, ETH Zürich, Rapporteur
  • Denis Andrault, Univ. Clermont Auvergne, Rapporteur
  • Ana Ferreira, Univ. College London, Examinateur
  • Angelika Rosa, European Synchrotron Radiation Facility, Examinateur
  • Huges Leroux, Univ. Lille, Examinateur and President
  • Sébastien Merkel, Univ. Lille, PhD Advisor

Jeff presented his work for 45 minutes, followed by an hour of discussion with the committee. After deliberation, the committee decided to award the Doctoral Degree to Jeffrey Gay.

Congratulations Jeff!

Virtual meeting on anisotropy in the upper mantle and transition zone

28 October 2022 | Posted in TIMEleSS news

TIMEleSS meeting on upper mantle and transition zone anisotropy Time to meet again! On Friday Oct 28th, 2022, TIMEleSS members met to discuss anisotropy in the upper mantle and transition zone.

John Keith Magali presented his latest results combining mantle flow models and results from the experiments in TIMEleSS.

Nice work, John!

Older news…


Partner institutions

Université de Lille CNRS   Westfälische Wilhelms-Universität Münster  Deutsche GeoForschungsZentrum

Participating laboratories

Unité Matériaux et Transformations, Université de Lille Institut für Geophysik, Universität Münster
Institut für Mineralogie, Universität Münster Chemistry and Physics of Earth Materials, GFZ

Funding bodies


Agence Nationale de la Recherche Deutsche Forschungsgemeinschaft  Projet financé par l'ANR