Our research uses Earth history as an example of one path a terrestrial planet can take during its evolution. Specifically, the interactions between the biosphere, atmosphere, and the geosphere of the Earth over geologic time drive our research interests. We use a combination of field geology, analytic and isotope geochemistry to test hypotheses and predictions made by numerical models. We utilize both traditional sedimentary records of biologic activity and records of biosphere-geosphere-climate interactions, such as glacial tills and altered ocean crust. This combined approach mirrors the interactions and feedbacks between the different spheres of the Earth, and helps shape ideas and theories about terrestrial planet evolution.