Energy and mass flux in the Upper Rhine Graben (EMURG): a mineral systems approach to hydrothermal regimes in graben structures

• Applicant: Professor Dr. Jochen Kolb
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 435358664

The Upper Rhine Graben hosts several geothermal power plants and historically mined ore deposits. Hydrothermal fluids play a main role in both, heat transport for geothermal energy and metal accumulation for ore deposits. In this project, we want to jointly investigate both systems with a holistic approach. Integrating heat and material transport allows a view at the entire mineral system from fluid source to metal or heat sink.The Upper Rhine Graben is one of the best sites to study this. We have access to samples from the fluid reservoir through drill cores and can compare the rocks with equivalents from surface outcrop. We will sample historical ore deposits and scalings in geothermal power plants in order to study mineral precipitation mechanisms. We will also determine the geochemistry of hot springs and geothermal fluids from wells. All this sample material is available in the Upper Rhine Graben, which will allow the holistic view from fluid-rock interaction in the reservoir of the hydrothermal fluid, the fluid composition to mineral precipitation.Our investigations will comprise petrological and geochemical studies of the various samples. We expect fundamental findings of fluid-rock interaction and precipitation mechanisms, in particular by comparing the recent systems of geothermal power plants with the fossil systems of ore deposits. We want to determine geochemical parameters that allow predictions about fluid source.With this holistic comparative study, we expect ground-breaking results on hydrothermal systems in graben structures like the Upper Rhine Valley. Possible applications range from exploration for geothermal energy use and ore deposits to the development of methods avoiding the scaling formation in power plants.

• DFG Programme: Research Grants
• Co-Investigators: Dr. Elisabeth Eiche; Privatdozent Dr. Benjamin Walter