1. Integrated Ocean Drilling Program, 1000 Discovery Drive, College Station, TX 77845, USA
2. Shell Exploration and Production Inc., 3737 Bellaire Boulevard, PO Box 481, Houston, TX 77001-0481, USA
3. University of Southampton, National Oceanography Centre, Southampton, European Way, Southampton SO14 3ZH, UK
4. School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, UK
5. Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843, USA
6. Present address: School of Earth and Environment, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK