The oceans are vitally important to an understanding of how the Earth works as an integrated system because its chemical composition records transfer of elements through the Earth's geochemical reservoirs as well as defining how physical, biological and chemical processes combine to influence issues as diverse as climate change and the capacity of the oceans to remove toxic metals. Much modern marine geochemistry aims to link and integrate studies of the modern oceans with work using proxies to define how ocean chemistry and the ocean/atmospheric system has changed through time on a number of...