Uncovering the Long Geological History of the Pelvoux Massif (Western Alps)





A team of geologists from ISTerren has reconstructed the long and complex history of the Pelvoux Massif in the Western Alps, revealing events that span more than 300 million years.


Figure 1. Simplified geological map of the southwestern Alps. The studied area, highlighted in red, corresponds to the Pelvoux Massif. ECM : External Crystalline Massifs ; GR : Grandes Rousses ; PFT : Penninic Frontal Thrust.
The story begins during the Variscan orogeny, when ancient mountain-building forces shaped the basement rocks and created deep faults. During the Jurassic and Cretaceous, these rocks were stretched and heated as the nearby oceans opened, reaching temperatures of up to 350°C.

Later, in the Late Cretaceous, north–south compression uplifted the massif and cooled its rocks, exposing them at the surface even before the Alps began to rise. Then, during the Alpine collision (35–25 million years ago), parts of the massif were buried again under thrust sheets, reheating the rocks unevenly, hotter in the north, cooler in the south.

These results show that the Western Alps are the product of a long sequence of tectonic and thermal events, and that the Alps’ current structure is strongly influenced by ancient faults and inherited geological features.

The study demonstrates the power of modern thermochronology to read the geological memory of rocks, providing a window into the deep-time evolution of one of Europe’s most iconic mountain ranges.


The full study is published on : AGU



References :

Angrand, P., & Mouthereau, F. (2021). Evolution of the Alpine orogenic belts in the Western Mediterranean region as resolved by the kinematics of the Europe-Africa diffuse plate boundary. BSGF-Earth Sciences Bulletin, 192(1), 42.

Balansa, J., Espurt, N., Hippolyte, J. C., Philip, J., & Caritg, S. (2022). Structural evolution of the superimposed Provençal and Subalpine fold-thrust belts (SE France). Earth-Science Reviews, 227, 103972.

Beucher, R., van der Beek, P., Braun, J., & Batt, G. E. (2012). Exhumation and relief development in the Pelvoux and Dora-Maira massifs (Western Alps) assessed by spectral analysis and inversion of thermochronological age transects. Journal of Geophysical Research, 117(F3), F03030.

Bellanger, M., Augier, R., Bellahsen, N., Jolivet, L., Monié, P., Baudin, T., & Beyssac, O. (2015). Shortening of the European Dauphinois margin (Oisans Massif, Western Alps) : New insights from RSCM maximum temperature estimates and 40Ar/39Ar in situ dating. Journal of Geodynamics, 83, 37–64.

Mulder, T., Callec, Y., Parize, O., Joseph, P., Schneider, J. L., Robin, C., et al. (2010).High-resolution analysis of submarine lobes deposits : Seismic-scale outcrops of the Lauzanier area (SE Alps, France). Sedimentary Geology, 229(3), 160–191.

Scientific contacts :

  • L. Boschetti – Géosciences Environnement Toulouse, Université de Toulouse Paul Sabatier, CNRS, IRD, Toulouse, France ; ISTerre, Université Grenoble Alpes, USMB, CNRS, IRD, UGE, Grenoble, France
  • F. Mouthereau – Géosciences Environnement Toulouse, Université de Toulouse Paul Sabatier, CNRS, IRD, Toulouse, France
  • S. Schwartz – ISTerre, Université Grenoble Alpes, USMB, CNRS, IRD, UGE, Grenoble, France
  • Y. Rolland – ISTerre, Université Grenoble Alpes, USMB, CNRS, IRD, UGE, Grenoble, France ; EDYTEM, Université Savoie Mont Blanc, CNRS, UMR 5204, Le Bourget du Lac, France
  • M. Bernet – ISTerre, Université Grenoble Alpes, USMB, CNRS, IRD, UGE, Grenoble, France
  • M. Balvay – ISTerre, Université Grenoble Alpes, USMB, CNRS, IRD, UGE, Grenoble, France
  • N. Cogné – Géosciences Rennes, Université Rennes 1, CNRS UMR 6118, Rennes, France
  • A. Lahfid – BRGM/ISTO, Orléans, France