The Grotzinger Group

Sharon Newman

Postdoctoral Scholar

Dustin Morris

Graduate Student

Daniela Osorio Rodriguez

Graduate Student

Cecilia Sanders

Graduate Student

Eva Scheller

Graduate Student

Nathan Stein

Graduate Student

Miquela Ingalls

Postdoctoral Scholar

Ted is a postdoctoral scholar at Caltech, advised by John Grotzinger and Jess Adkins.  He is interested in coupling stable isotope geochemistry and sedimentary geology to figure out how Earth's ocean records changing biogeochemical processes.  He is using trace sulfate in calcite and dolomite (Carbonate Associated Sulfate, CAS) to test the influence of local processes on proxies of global biogeochemical cycles.  CAS is a proxy for seawater sulfate, and informs the global redox balance of oxygen and carbon.  However, by using CAS in well-understood limestone successions (end-Ordovician on Anticosti Island, Quebec), he demonstrated that postdepositional diagenesis also affects CAS records.  Now, using well-exposed and correlatable Late Permian strata in the Guadalupe Mountains, TX, he is examining the importance of local environmental variability on the CAS proxy.  He is also examining a Mesoproterozoic base metal sulfide deposit (Belt Supergroup, MT) to study sulfur cycling in an ancient hydrothermal vent.

Click here to access his paper "Large carbonate associated sulfate isotopic variability between brachiopods, micrite, and other sedimentary components in Late Ordovician strata"

Ted Present

Postdoctoral Scholar

tpresent(at)caltech(dot)edu