Email: als@gps.caltech.edu

B.A., Williams College, 1991; M.Sc., Dartmouth College, 1996; Ph.D., Indiana University (Bloomington), 2001. Assistant Professor, Caltech, 2003-10; Associate Professor, 2010; Professor, 2010-.

Isotopic biogeochemistry and organic geochemistry, including:

controls on the distribution of hydrogen and sulfur isotopes in lipids, sedimentary organic matter and petroleum; biomarker and isotopic records of the Neoproterozoic; and the marine organic carbon cycle. Also, the development and application of novel isotopic analytical methods for biogeochemistry, such as compound-specific analysis of 34S in volatile organics, and the analysis of 13C in whole cells sorted by flow cytometry.