Experimental studies on geochemical cycling and mineralogical modifications during alteration of ultramafic lithologies in hydrothermal systems

Abstract

Hydrothermal alteration processes are key to the geochemical cycle between the oceans and the oceanic crust and also for mass transfer associated with subduction zone related environments. This PhD project uses the flexible reaction cell experimental technique to simulate and study three selected hydrothermal processes under well-defined laboratory condition. As a premise for potential tracer applications, a 1st study investigates Li and B isotope fractionation during the crucial serpentinization associated mass transfer processes. Due to a high potential of H2 production serpentinization driven hydrothermal systems are considered a likely candidate for the origin of life. A 2nd study investigates the serpentinization of troctolites that represent a chemical analogue for ancient komatiitic rocks. A 3rd study investigates the impact of hydrothermal systems on marine DOM that not only plays an important role in the global carbon cycle but also is crucial for marine heterotroph life.