Phosphorous Diagenesis and Burial in Marine Sediments

磷是海洋生物生产所必需的营养物质。海洋沉积物中磷的成岩作用和埋藏效率对海洋生物地球化学循环起着重要的控制作用。随着地质时间的推移，海洋中磷的水平将在很大程度上受到其在海洋沉积物中的埋藏速度的控制。这对于开发现实的、可预测的生物地球化学模型和解释沉积记录至关重要。使用一种新的选择性顺序提取(Sedex)技术产生的详细的固相磷数据将被收集到不同的典型海洋环境和一个河流-河口-三角洲系统(密西西比河)。通过研究沉积物中固相磷随深度的再分配，结合孔隙水和其他固相数据，将确定负责海洋沉积物中磷保留的S相。这种方法提供了对早期成岩化学反应的洞察，这些化学反应负责这些相的形成和保存。将使用成岩模拟来检验根据固相和孔隙水数据所作的解释，并就所推断的化学过程的速率得出进一步的结论。比较沉积物-水界面附近精细尺度(Mm)深度区间内固相磷与孔隙水梯度的数量和化学性质，可以定量和表征该界面附近的磷循环和埋藏效率。通过比较密西西比河/河口悬浮物和相关三角洲沉积物中的固相磷形态，可以量化颗粒磷在穿越特定大陆-海洋界面过程中的生物地球化学处理程度。将产生对磷埋葬的沉积环境控制，并据此建立全球海洋磷预算。

Phosphorus is an essential nutrient for biological production in the ocean. Diagenetic processing and burial efficiency of P in marine sediments exert a major control on marine biogeochemical cycles. Over geologic time, the level of P in the ocean will be controlled to a large extent by its rate of burial in marine sediments. This is crucial to the development of realistic, predictive, biogeochemical models and to the interpretation of the sedimentary record. Detailed solid-phase p data, generated using a new selective sequential extraction (SEDEX) technique, will be collected for a diverse suite of typical marine environments and one river-estuary-delta system (the Mississippi). Phase s responsible for P retention by marine sediments will be identified by examining solid-phase P redistribution with depth in sediments in conjunction with pore water and other solid-phase data. This approach provides insight into the early diagenetic chemical reactions responsible for formation and preservation of these phases. Diagenetic modeling will be used to test interpretations made on the basis of solid-phase and pore water data and to draw further conclusions as to rates of the chemical processes inferred. Comparison of the quantity and chemical nature of solid-phase P to pore water gradients over fine-scale (mm) depth intervals near the sediment-water interface will permit quantification and characterization of P cycling and burial efficiency near this interface. The extent of biogeochemical processing of particulate P during transit across a particular continent-ocean interface will be quantified by comparing solid-phase P speciation in Mississippi River/Estuary suspended matter with that in associated deltaic sediments. Depositional environmental controls on P burial will be generated from which to construct a global marine P budget.