Major research interests

Sediments that re-crystallize during diagenesis disclose a wealth of information, either on environmental or diagenetic conditions. My work aims at disentangling diagenetic signatures from environmental signatures to deduce meaningful geological information from chemical sediments. To quantify underlying processes, I use isotope ratios of stable elements including magnesium, strontium, silicon, and oxygen as well as Rare Earth elements.

I am intrigued by the possibility of improving the analytical precision of metal(oid) isotope ratio analysis to allow resolving small differences in the triple isotope fractionation exponent (θ). With more precise measurements, different mass-dependent isotope fractionation processes (generally non-equilibrium versus equilibrium) will become analytically resolvable. This allows identifying differences in mineral formation processes, information that cannot be gained from δ-values alone.

I am moreover interested in the redox history of the Earth and the possibility that the development of life shaped the Earth’s redox landscape. My previous research suggests that seawater oxygenation in the terminal Neoproterozoic was supported by a growing sponge community.

Current research areas

Microbially mediated dolomite formation
The distinction of microbial dolomite from diagenetic dolomite (that forms via Mg-for-Ca replacement) will allow assessing the causes of drastic changes in dolomite abundance through Earth history. Currently, I investigate biogenic dolomite formation in microbial mats that form in hypersaline environments in trying to find an isotopic signature that is diagnostic to this mode of dolomite formation.

Cherts as recorders of surface vs. diagenetic conditions
Cherts, quartz rich sedimentary rocks, form from precursors made of amorphous silica over a wide depth- and temperature range during burial diagenesis. Their complex genesis impedes on a straightforward interpretation of O- and Si-isotope ratios in ancient cherts that contain a yet un-decoded record of surface temperatures, seawater isotope composition and thermal conditions in the Earth’s crust. I investigate the impact of detrital silicates on rates of chert formation and O-isotope ratios to elaborate our understanding to what extent this archive records surface- or diagenetic conditions. To further contribute to the long-standing question of the significance of O-isotope ratios in chert, I currently develop a new O- and Si-isotope- based approach that allows determining formation temperatures and O-isotope ratios of fluids independently.