The Department of Earth Sciences is one of the core departments in USC's Geobiology initiative and has a strong interest in pushing the boundaries of interdisciplinary research. Geobiology is an emerging field of research that focuses on the interface between Earth and life sciences. Life has left its imprint on the atmosphere, the hydrosphere, and the geosphere, and these systems have undoubtedly left their own signatures on life as it has evolved. Geobiological study at USC is dedicated to deciphering the interaction of the Earth and its biosphere at all scales, from small to large, from ancient to modern. USC is home to one of the most exciting and extensive Geobiology programs in the world. In the past decade, USC has brought together a diverse group of scientists covering virtually all of the areas required to launch an intellectual assault on the major questions in Geobiology. These areas include: geology, biology, chemistry, geochemistry, paleobiology and, more recently, molecular genetics and genomics.