Stephen Marshak is Professor of Geology at the University of Illinois, Urbana-Champaign, where he is also the Director of the School of Earth, Society, and Environment. He holds an A.B. from Cornell University, an M.S. from the University of Arizona, and a Ph.D. from Columbia University. Steve s research interests lie in structural geology and tectonics. This work has taken him into the field on a number of continents. Steve loves teaching and has won his college s and university s highest teaching awards. In addition to research papers and Essentials of Geology, Steve has authored Earth: Port...