His research interests are the light stable isotope (e.g., H, C, N, O, S) geochemistry of sedimentary rocks and organic materials. This work is largely focused on making accurate and highly precise isotope ratio measurements in his gas source mass spectrometry laboratory, with an eye towards novel and technically challenging isotope systems. These observations are employed to answer a number of questions in Earth science, but mainly paleoclimatology and paleoenvironmental reconstruction, and marine biogeochemistry.