[1
]Department of Earth Sciences; University of Oxford; Oxford UK
[2
]Now at Department of Earth Sciences; Royal Holloway University of London; Egham Surrey
UK
[3
]Now at Institute of Earth Sciences, Géopolis; University of Lausanne; Lausanne Switzerland
[4
]Camborne School of Mines and Environment and Sustainability Institute; University
of Exeter; Penryn UK
[5
]Shell International Exploration & Production B.V; Rijswijk GS the Netherlands
[6
]Now at Shell R&D Houston; Vashon WA USA
[7
]Shell International Exploration and Production Inc.; Houston TX USA