 in Geology from the University of Minnesota of 1955, and a Ph.D. in Geochemistry from Johns Hopkins University in 1959.From 1960 to 1989 he was a professor in the Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics at UCLA, where he also served terms as chair of the Department of Geology, chair of the Department of Earth and Space Sciences, and director of the Institute of Geophysics and Planetary Physics.In 1989 he joined Stanford University as professor in the Department of Geological and Environmental Sciences and Dean of the School of Earth Sciences.