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P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，海洋中磷的水平在很大程度上受其在海洋沉积物中的埋藏率的控制。这对于发展现实的、可预测的生物地球化学模型和解释沉积记录是至关重要的。详细的固相p数据将使用一种新的选择性顺序提取（SEDEX）技术生成，用于收集各种典型海洋环境和河流-河口-三角洲系统（密西西比河）的数据。通过结合孔隙水和其他固相数据，研究沉积物中随深度的固相P再分布，确定海洋沉积物中负责P保留的相。这种方法提供了对这些相形成和保存的早期成岩化学反应的深入了解。成岩模型将用于检验基于固相和孔隙水数据所作的解释，并就推断出的化学过程速率得出进一步的结论。将固相P的数量和化学性质与孔隙水梯度在沉积物-水界面附近的细尺度（mm）深度区间进行比较，可以量化和表征该界面附近的P循环和埋藏效率。通过比较密西西比河/河口悬浮物与相关三角洲沉积物中固相P的形态，可以量化颗粒P在穿越特定大陆-海洋界面过程中的生物地球化学加工程度。沉积环境对磷埋藏的控制将由此产生，并据此构建全球海洋磷收支。

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.