Research Scientist, Physics and Geosciences departments, University of Arizona

Florida State University, Robert O. Lawton Distinguished Professor

Chair in Isotope Geosciences, University of Nottingham & British Geological Survey

Professor Emerita of Archaeological Science, University of Oxford

Professor Emeritus, Macquarie University

Professor of Earth System Sciences, Stanford University

Carnegie Institution for Science

Michigan State University, GSI, NSCL

University of Freiburg

Professor of Soil Microbial Ecology, The University of Manchester