November 2009 - August 2011
Trained as a metamorphic petrologist/aqeuoes geochemist Frieder joined the DOEI in October 2009. He is mainly interested in fluid-rock interactions in the aging oceanic lithosphere and carbonation of olivine-rich rocks. Frieder uses a combination of petrographic and spectroscopic methods, hydrothermal experiments and thermodynamic modeling to better constrain the impact of large- scale on- and off axis hydrothermal alteration and weathering processes on the chemistry of the oceans, as well as on the mineralogical evolution of the oceanic crust.
The exposure of mantle material at the seafloor and resultant reactions with seawater (i.e. serpentinization) has received considerable attention as a source for H2-based microbial ecosystems, and as a potential venue for the origin of life. Moreover, serpentinized peridotites may represent a significant sink for CO2 in the global carbon cycle. Yet, our understanding of serpentinization processes and carbonation of serpentinite is still in its infancy.
As a post-doctoral scholar Frieder investigates the mineralogy and geochemistry of hydrothermally-altered mantle rocks from a broad variety of geotectonic settings including mid-ocean ridges, continental rifted margins and fore-arc settings of subduction zones. Frieder analyzes the compositions and associations of mineral assemblages in these rocks and uses them to trace the sequences of (meta-) stable phase equilibria. In addition, he uses the modeling codes SUPCRT92 (Johnson et al. 1992) and EQ3/6 (Wolery et al. 1992) to calculate gas fugacities, solute activities of intergranular fluids, alteration temperatures and fluid fluxes, data, which are difficult to constrain otherwise. Complemented by hydrothermal experiments he gains deeper insights into serpentinization as a function of rock composition, temperature and time.
Frieder worked as a visiting research associate at the Laboratory for Atmospheric and Space Physics in Tom McCollom’s lab and as a post-doctoral investigator at the IACT-CSIC in Carlos Garrido’s group. He received a Ph.D. from the Department of Geosciences at the University of Bremen (Germany) in 2009 while working with Wolfgang Bach.