1. Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA
2. School of Science, University of Waikato, Hamilton 3240, New Zealand
3. Istituto di Geoscienze e Georisorse, Consiglio Nazionale delle Ricerche, Area della Ricerca di Pisa, PI, 56124, Italy
4. Department of Geology, University of Maryland, College Park, Maryland 20742, USA
5. FB-Geowissenschaften, University of Bremen, Bremen 28359, Germany
6. GNS Science, Lower Hutt 5011, New Zealand
7. Institute for Geophysics, University of Texas at Austin, Austin, Texas 78758, USA