I am a geologist with interests in surface Earth history. I use stratigraphy and geochemistry to address questions about the co-evolution of life and Earth’s surface environments in deep time. Most of the rocks I study are carbonates, and I focus on early Paleozoic and Neoproterozoic time. I’m especially interested in 1) the end-Ordovician mass extinction and Ordovician/Silurian icehouse, 2) carbon and sulfur cycling in deep time, 3) effects of diagenesis on stable isotope ratios of C, O, S, Ca, and Mg, and 4) the origin and geochemistry of dolomite.
My field work has recently focused on sedimentary rocks in the Great Basin (Nevada, Utah) and modern playa lake deposits in California (Deep Springs Lake). Upcoming projects will include field work in Wyoming and Colorado. Past field work has included the Canadian Arctic, Mongolia, Italy, Atlantic Canada, and the Rocky Mountains.