This research used samples and data provided by the Ocean Drilling Program (ODP). ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. Financial support by High Lat resources (HPRI-CT-2001-00125) through the European Commissions "Access to Research Infrastructure" action of the Improving Potential Programme is acknowledged. R.E. Clayton acknowledged research funding from The Royal Society, United Kingdom (grant number 21380).