1,1,4,5,6,- 1ITES, University of Strasbourg-CNRS, Strasbourg, France (manat@unistra.fr)
- 2CNR University of Torino, Torino, Italy
- 3University of Liverpool, Liverpool, UK
- 4Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
- 5South China Sea Institute of Oceanology, Guangzhou, China
- 6Lavoisier H2, Geoconsult, Chamonix, France
- 7Rock-Water Interaction Group, University of Bern, Switzerland
- 8Mantle8, Grenoble, France
The call for an “energy transition” undeniably requires finding low-emission energies, among which serpentinization-sourced natural hydrogen (H2) is one potential candidate. However, the knowledge needed to successfully explore for this new energy source, i.e., to understand when and where natural H2 forms during the Wilson cycle, is yet incomplete. Answering these questions is challenging and requires not only a much-improved understanding of serpentinization processes, but also a deep understanding of the geological systems in which serpentinization occurs.
The aim of this contribution is not only to focus on how natural H2 forms, migrates and is trapped, but also to investigate the characteristics and evolution of the geological systems that hosted, or host, serpentinization and potential natural H2 production. More specifically, we examine the evolution of mantle rocks during their emplacement in ocean continent transitions (OCTs) and their later reactivation and emplacement in rift-inversion orogens. To do so, we review the evolution of OCT-derived ophiolites located in the Alpine system. We focus on two settings: the Western Pyrenean fossil OCT exposed in SW-France and the Grischun-Malenco fossil OCTs exposed in SE-Switzerland and northern Italy. Their choice is linked to the fact that they are not only the best documented and exposed examples of OCT-derived ophiolites worldwide, but also to the fact that they bear active H2 systems. Compared with ophiolites derived from Mid Ocean Ridges (MOR) or Supra-Subduction Zones (SSZ), OCT-derived ophiolites are substantially different in terms of mantle rock composition, emplacement mechanisms during collision, and potential for natural H2 production.
In this study, we review the characteristics of OCTs based on the well calibrated distal Iberian margin and the Grischun-Malenco fossil OCT. We then synthesize the state-of-the art knowledge on these well described OCTs and OCT-derived ophiolites and their potential for natural H2 systems. Finally, we discuss how far this knowledge can be used to explore for native H2 along the Tethyan suture zones in Eastern Europe, and in collisional orogens in general.
How to cite: Manatschal, G., Dimasi, F., Gasser, Q., Blin, C., Chenin, P., Ulrich, M., Frasca, G., Kusznir, N., Zwaan, F., Zhang, C., Gaucher, E. C., Alt-Epping, P., Pierre, S., Ducoux, M., and Masini, E.: The fate of the subcontinental mantle in Alpine-type rift inversion orogens and its significance for natural H2 exploration, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-41, https://doi.org/10.5194/egusphere-alpshop2026-41, 2026.
