The Spittellamm-cleft, an Alpine fissure hosted in the Grimsel Granodiorite, was discovered during the construction of the new Grimselsee barrage in July 2019 and then covered. Some isolated cleft material has already been investigated; however, a systematic approach starting with sampling on-site during the planned re-opening in spring 2026 offers unique opportunities to addressing diverse scientific questions relating to fluid circulation and fluid-rock interactions in exhuming orogens. Findings offer relevant constraints not only on fundamental scientific questions, but also on applied topics, including deep basement surface water circulation and geothermal energy.
Sample material will be collected at the Spittellamm-cleft (guided by Kraftwerke Oberhasli AG -KWO) and its direct surroundings. The collected materials (minerals, rocks, altered zones) will be characterized petrographically and documented to serve as a collection for later use. Possible projects include stable and radiogenic isotopes of the late-stage cleft materials (e.g., calcite, clays) to trace sources of fluids and dissolved matter in them, to use fluid inclusion systematics to constrain cleft genesis, or radiometric dating to constrain timing of cleft formation in the exhuming Aar massif. Comparison with literature data and/or data/analyses from nearby clefts may also be possible.
This project is available with a start in spring 2026, only.
Advisors: PD Dr. Malte Junge, Prof. Thomas Pettke
Specialities: EM
University: BE