Fluids and fluid flow in the upper crust transport energy and dissolved elements, they facilitate mineral reactions and rock weathering, and they strongly reduce rock strength and are thus a controlling factor in earthquake seismicity and geo-engineering. Clay minerals have a major influence on fluid-rock interaction and rock mechanics in these settings. Their surface properties give clays a high chemical reactivity and their physical properties make them effective lubricants (on faults) and also sealants (in rock reservoir). We study the chemical and isotopic composition of natural geofluids and gases from active systems, and their interaction with the surrounding rocks with an emphasis on the role of clay minerals.
Applications: Constraining the origin and age of crustal fluids to reconstruct transport processes; determining the availability of hydrogen or methane as a prerequisite for life in the deep biosphere; studying the role of swelling and non-swelling clays in rock deformation and in the integrity of geologic reservoirs; determining the role of clay surfaces for sorption-desorption chemical reactions and their role in fluid composition; surface monitoring degassing intensity and gas composition of active volcanoes and fumaroles to understand eruption processes and aid hazard assessment.
Associated and finished projects: