Orogenic hydrothermal systems often rely on recharge of meteoric water in mountainous areas, fluid circulation and heating of fluids down to depths of up to 10 km have to ascent and eventually leading to hot water springs. Such hydrothermal cells are of great interest for the exploration of geothermal energy within the Alps. In past research projects, we discovered the importance of brittle fault systems and associated kinematics in order to provide information on pathways allowing fluid circulation in quantities being substantial for the successful exploitation of heat. With this respect, quantitative information on the 3D geometries of flow paths, associated brittle tectonites and permeabilities is mandatory. In active hydrothermal systems, deep parts of hydrothermal cells are not accessible with enough spatial resolution by geophysical techniques. For this reason, we investigate in this study exhumed paleo-hydrothermal fault systems by means of quantitative mapping at a multitude of scales (remote sensing on aerial photographs, DEMS and drone images), on selected hand specimen and thin sections. This information allows the generation of 3D models visualizing and quantifying 3D pathways for fluid flow in a comprehensive manner. In addition, special emphasis can be paid to porosity forming (dilatancy by brittle deformation) and destroying (e.g. hydrothermal mineral precipitation) processes allowing to link porosity evolution to relative time sequences. In this sense, high-end analytical techniques such as light optical and scanning electron microscopy in combination with digital images analysis can be applied. This part of the project will be conducted in close collaboration with Prof. Beda Hofmann of the museum of natural sciences. There is opportunity for different MSc projects. Interested MSc students can select from different study sites (e.g. lower Engadin, upper Engadin, Grimsel pass, Furka pass, Wildhorn area, Lac de Fully). Also collaboration within the Geotex Rhône project (joint project between Structural Geology and RWI) is possible.
Advisors: Prof. Marco Herwegh, Prof. Alfons Berger, Dr. Timothy Schmid
University: BE