622551elderfieldvol6.jpg The oceanic record is central to monitoring and interpreting past climate change. Because the oceans are such a large carbon reservoir, fluctuation in atmospheric C0 2 , and hence global temperature, are intimately linked to ocean composition. The factors that control past ocean chemistry are complex, and multi-proxy methods are the key to understanding them. My main research at present is to proxy seawater composition using the metal and isotopic contents of the carbonate shells of marine microfossils: planktonic and benthic foraminifera and to evaluate factors such as dissolution that influence carbonate chemistry. I am also interested in long-term records using bulk carbonates and ocean geochemical processes in general such as seawater composition and fluid flow through oceanic crust. E-mail: email@example.comElderfield, H. is the author of 'Oceans And Marine Geochemistry ', published 2006 under ISBN 9780080451015 and ISBN 0080451012.