1. Ocean Sciences; College of Natural Sciences; Bangor University; Menai Bridge; Anglesey; LL59 5AB; UK
2. Department of Earth and Atmospheric Sciences; University of Alberta; Edmonton; Alberta; T6G 2E3; Canada
3. Earth and Planetary Sciences; Department of Physical Sciences; Grant MacEwan University; P.O. Box 1796; Edmonton; Alberta; T5J 2P2; Canada
4. School of Environmental Sciences; University of Liverpool; Liverpool; L69 7ZT; UK
5. Laboratoire EPOC (Environnements et Paléoenvironnements OCéaniques), UMR-CNRS 5805; Université Bordeaux I; Avenue des Facultés, 33405 Talence; France
6. Geological Survey of Canada-Atlantic; Box 1006; Dartmouth; Nova Scotia; B2Y 4A2; Canada