"Processes at the Sediment-Water Interface of the Peru Shelf: Biogenic Fluxes and Phosphorite Formation"

“秘鲁大陆架沉积物-水界面的过程：生物通量和磷矿形成”

• 批准号: 9014801
• 负责人: Michael Arthur
• 金额: $ 33.9万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-11-15 至 1994-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9014801&HistoricalAwards=false
• 关键词: Processes; Sediment; Water; Interface; Peru

Two expeditions to the Peru Continental Margin will investigate biogeo chemical processes near the sediment surface. The P.I:'s will measure the fluxes of biogenic components across the sediment-water interface linked to bacterial mat activity, organic matter diagenesis, iron redox cycling, phosphate precipitation and sedimentary denitrification. The selected study area (11o40"S - 15oS; 50 m -600 m) exhibits high persistent upwelling, primary production and sediment organic carbon; ubiquitous microbial mats; modern phosphorites; and near-zero oxygen and "nitrate deficit" in the near-bottom water column. A smaller are (1300 sq. Km at 13o30'S), selected to study benthic processes will be box cored in a bottom-navigated array to provide a detailed map for submersible operations and bottom experiments. Fluxes will be obtained with benthic flux chambers (Landers), microelectrodes (Profilers) and mm-scale pore water profiles (box cores and Whole-Core Squeezer). The P.I:'s will also deploy near-bottom sediment traps and current meters to determine transport velocities and directions and the biogeochemical sources of particles entrained in the poleward bottom flow. Both long- and short- term in situ experiments on the seabed will test theories concerning (1) apatite nucleation and solubility; (2) sediment disturbance and sediment starvation; (3) patchy distributions of laminated sediments, mats, organic carbon and pellets; and (4) Fe- and O2-redox driven phosphorus reaction.

秘鲁大陆边缘的两次考察将调查沉积物表面附近的生物地球化学过程。 P.I：将测量与细菌垫活动、有机质成岩作用、铁氧化还原循环、磷酸盐沉淀和沉积物反硝化相关的沉积物-水界面上生物成分的通量。 选定的研究区域（11o40"S - 15oS；50 m -600 m）表现出高持续上升流、初级生产和沉积物有机碳；无处不在的微生物垫；现代磷矿；以及近底水柱中近乎零的氧气和“硝酸盐赤字”。选择用于研究底栖过程的较小区域（1300 平方公里，南纬 13o30'）将在一个盒子中进行取芯。 底部导航阵列为潜水操作和底部实验提供详细的地图。 通量将通过底栖通量室（Landers）、微电极（Profilers）和毫米级孔隙水剖面（盒芯和全芯挤压器）获得。 P.I: 还将部署近海底沉积物捕集器和海流计，以确定运输速度和方向以及 向极地底部流中夹带的颗粒的生物地球化学来源。 海底的长期和短期原位实验都将检验有关以下方面的理论：（1）磷灰石成核和溶解度； (2)泥沙扰动和泥沙匮乏； (3)层状沉积物、席子、有机碳和颗粒的不均匀分布； (4) Fe-和O2-氧化还原驱动的磷 反应。