1. Earth and Environmental Sciences; Lehigh University; Bethlehem; Pennsylvania; USA
2. Department of Geological and Environmental Sciences; Stanford University; Stanford; California; USA
3. Geowissenschaften; Technische Universität Bergakademie Freiberg; Freiberg; Germany
4. Geological Survey of Norway; Trondheim; Norway
5. U.S. Geological Survey; Menlo Park; California; USA