Phosphorus Accumulation in Cenozoic Marine Sediments

小行星9416593 大陆风化向海洋提供溶解磷在长时间尺度上调节海洋生产力和沉积物埋藏方面起着关键作用。尽管这一重要性，鲜为人知的是，新生代的历史，从海洋的P通量。 本研究的三个主要目的是：（1）了解新生代海洋沉积物中磷累积速率的控制因素，（3）利用质量平衡模型解释这些磷累积速率的变化。 海洋沉积物中P的地球化学分布的测量将使用已建立的顺序提取技术，区分五个沉积P组分;其中四个是溶解，活性P和第五个是碎屑P的埋藏汇。P的积累率将计算从总活性P浓度测量。 还将通过较短的分析方法测量总磷浓度，以确定磷累积率，其中已证明碎屑磷对总磷的贡献可忽略不计。为了解磷累积率的控制因素而进行的研究地点包括具有类似地表水生产力的地点的深度断面，沿着生产力梯度的纬度样带， 和不同岩性的沉积物。 将选择记录新生代海洋沉积物中磷累积速率随时间变化的地点，以确保在全球生产力和沉积物累积方面具有重要意义的区域的地理覆盖范围（包括大西洋和太平洋的赤道地区、高纬度北太平洋和南大洋）。 对新生代磷富集记录的解释将与其他海洋地球化学记录联系起来 历史，如锶和碳同位素。 这项工作将产生实质性的见解，在P通量的变化，并从海洋水库在很长的时间尺度。

9416593 DELANEY The supply of dissolved phosphorus to the oceans from continental weathering plays a key role in regulating oceanic productivity and sediment burial on long time scales. Despite this importance, little is known about the Cenozoic history of P fluxes to and from the ocean. The three main objectives of this research are: (1) to understand the controls on P accumulation rates in Cenozoic marine sediments, and (3) to interpret these P accumulations rate variations using mass balance models. Measurements of P geochemical distributions in marine sediments will use established sequential extraction techniques which differentiate five sedimentary P components; four of these are burial sinks for dissolved, reactive P and the fifth is detrital P. P accumulation rates will be calculated from total reactive P concentration measurements. Total P concentration measurements will also be applied, by shorter analytical methods, to the determination of P accumulation rates where it has been demonstrated that detrital P is a negligible contribution to total P. Sites to be studied to understand the controls on P accumulation rates include depth transects of sites with similar surface water productivity , latitudinal transects of sites along a gradient of productivity, and sediments of different lithologies. Sites for the documentation of temporal variations in P accumulation rates in Cenozoic marine sediments will be selected to ensure geographic coverage of regions significant in terms of global productivity and sediment accumulation (including the equatorial regions of the Atlantic and Pacific, the high latitude North Pacific, and the Southern Ocean). Interpretation of the Cenozoic record of P accumulation will be linked to other geochemical records of ocean history, such as strontium and carbon isotopes. This work will yield substantial insights into the variations in P fluxes to and from the oceanic reservoir over long time scales.