a School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK b Lamont-Doherty Earth Observatory at Columbia University, Comer Geochemistry Building, 61 Route 9W/PO Box 1000, Palisades, NY 10964-8000, USA c Divisão de Geologia e Georecursos Marinhos, Instituto Português do Mar e da Atmosfera I.P., Rua C do Aeroporto, 1749-077 Lisboa, Portugal d In...
