Sulfur and oxygen isotopes in sulfate: applications and limits

Distinct fluctuations in sulfate sulfur and oxygen stable isotope compositions (delta34SSO4, Delta33SSO4, delta18OSO4, and Delta17OSO4) reflect some of the most extreme changes in Earth history. I will present two such cases of extreme changes: 2009-2013 modern riverine dissolved sulfate delta34SSO4 and Delta17OSO4 data from the largest river in North America that show heavy anthropogenic perturbation, and the ~635 Ma Marinoan “Snowball Earth” post-glacial sedimentary rock record of Earth’s most negative Delta17OSO4. In addition, I will explore how the modification of these dramatic isotope signals complicates their interpretation.