Stable strontium isotopes δ88/86Sr) are increasingly used to study the modern marine Sr budget and changes in the marine carbonatefactory over geological time. Both are linked to the long-term carboncycle through processes such as continental weathering,hydrothermal alteration of oceanic crust, and carbonate burial.This seminar focuses on the role of the common evaporite mineralsgypsum (CaSO4·2H2O) and anhydrite (CaSO4) in the stable Srisotope budget of the ocean. I will address three main questions:(1) Does large-scale evaporite deposition, such as during theMessinian Salinity Crisis, affect the stable Sr isotope composition ofseawater? (2) Does dissolution of ancient gypsum and anhydriteaffect the δ88/86Sr value of rivers? And (3), can the δ88/86Sr value ofancient seawater be reconstructed from gypsum and anhydrite?Finally, I will present ongoing work that builds on these studies andaims to quantify atmospheric CO2 consumption by carbonateweathering in river catchments using stable Sr isotopes.
