Geochemistry of marine sediments

海底堆积的沉积物代表了一系列时间尺度上海洋和气候变化的自然档案。这些变化需要完全记录下来，并确定其原因，以便可以对气候和环境变化的模型进行测试，并制定对未来气候变化的预测。我的研究涉及根据海底沉积物岩心的化学和同位素特性建立过去海洋和大气变化的记录。这些特性可以作为沉积物积累时海洋中特定条件的指标。例如，我们能够确定沉积物颗粒的来源和海底颗粒的运输方式，覆盖核心地点的海洋表层水的生产力，表层水的温度，底层水的氧合作用，海洋和大气中二氧化碳的丰度，以及过去浮游植物营养物质的利用程度。所有这些信息都可以拼凑在一起，得出地球历史上以前时期海洋的状态图，这可以用来找出海洋如何影响大气，以及如何受到大气的影响。这项申请要求支持对赤道东太平洋的古海洋学、热带和极地地区海洋和大气变化之间的联系的研究，以及应用这些方法来发现古代富含有机物质的沉积岩的可能形成模式。

The sediments accumulating on the sea-floor represent natural archives of oceanographic and climatic changes over a range of time-scales. Such changes need to be fully documented, and their causes identified, so that tests can be made of models of climate and environmental change, and predictions of future climate variations can be formulated. My research involves the construction of records of past oceanographic and atmospheric changes from the chemical and isotopic properties of cores of sediments recovered from the sea floor. Such properties can be used as indices of particular conditions in the ocean at the time the sediment was accumulating. For example, we are able to determine the sources of the sediment particles and the mode of transport of the particles on the sea floor, the productivity of the surface waters of the ocean overlying the core site, the temperature of the surface waters, bottom water oxygenation, the abundance of CO2 in the ocean and in the atmosphere, and the extent of phytoplankton nutrient utilization in the past. All of these pieces of information can be fitted together to arrive at a picture of the state of the ocean at previous times in Earth's history, and this can be used to find out how the ocean influences, and is influenced by, the atmosphere. This application requests support for studies of the palaeoceanography of the eastern equatorial Pacific, linkages between oceanic and atmospheric changes in the tropics and the polar regions, and the application of these approaches to discovering the possible modes of formation of ancient organic-rich sedimentary rocks.