Quantifying Partitioning of Trace Elements into Seafloor Hydrothermal Deposits Using Paired Vent Fluids and Solids

使用成对的喷口流体和固体量化微量元素在海底热液矿床中的分配

• 批准号: 1536480
• 负责人: Margaret Tivey
• 金额: $ 18.9万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536480&HistoricalAwards=false
• 关键词: Quantifying; Partitioning; Trace; Elements; into

Hydrothermal vents are an important source of sulfide mineral deposits to the ocean floor, but the processes of how trace elements get incorporated into the hot fluids and their corresponding sulfide chimneys is poorly understood. This project will measure trace element concentrations in fluid-chimney pairs from a natural hydrothermal vent system. The data from this project will enhance our understanding of how trace elements transition between the fluid and corresponding mineral, as well as be included into studies that aim to quantify trace element fluxes from hydrothermal vents to the deep ocean and modeling studies focused on formation of massive sulfides and metal remobilization. This project will support the training of undergraduate and graduate students, and results will be shared broadly through the creation of educational videos.Use of vent fluids and corresponding chimney linings to test hypotheses of partitioning has been hampered in the past by a lack of trace element data for both vent fluids and solids due to the very low concentrations. Recent efforts using improved analytical techniques now make investigations of trace element partitioning possible. This project will use a natural hydrothermal vent system to investigate trace element partitioning from fluids into sulfide minerals that precipitate along the linings of the chimney conduits, in contact with the hot vent fluids, at conditions difficult to reproduce in the laboratory. Analyses will be done on a set of fluid-chimney pairs (fluid and chimney sampled at the same time). Data and analyses from this project will be used to test the following two hypotheses: 1) Minerals precipitating from vent fluids along linings of chimneys incorporate some trace elements in a characteristic manner, with partitioning dominantly a function of element concentrations, and with pH, temperature, redox, and ligand concentration affecting free versus total concentrations; and 2) Seafloor sulfide deposits record critical information about both the trace element compositions of the fluids from which they formed, and about environmental conditions at the time of precipitation; thus, trace element distributions could be used as proxies for environmental conditions such as pH, redox, temperature, and/or metal concentrations.

水热通风孔是硫化物矿物沉积物到海底的重要来源，但是对痕量元素如何掺入热液及其相应的硫化物烟囱的过程知之甚少。该项目将在天然水热系统中测量流体芯片对中的微量元素浓度。 该项目的数据将增强我们对痕量元素如何在流体和相应矿物质之间转变的理解，并将其纳入旨在量化从热液通风口到深海的痕量元素通量和建模研究的研究，并建模研究集中于形成大规模的硫化物和金属重生。该项目将支持对本科和研究生的培训，并将通过创建教育视频来广泛分享结果。使用通风液和相应的烟囱衬里来测试分区的假设，这在过去缺乏由于浓度很低而缺乏触发域的痕量元素数据，从而阻碍了分区的假设。现在，使用改进的分析技术的最新努力使对痕量元素分区的研究成为可能。该项目将使用天然的热液排气系统研究从烟囱导管的衬里沿硫化物矿物的痕量元素分配，并与热通风液接触，并在实验室难以繁殖的条件下接触。分析将在一组流体 - 芯片对（同时取样的流体和烟囱）上进行。该项目的数据和分析将用于测试以下两个假设：1）沿着烟囱衬里的排气流体沉淀出排气流体的矿物质以特征性的方式结合了一些痕量元素，并具有元素浓度的主要分配，并且具有pH，温度，氧化和配体浓度，并影响了自由浓度与总浓度相比； 2）海底硫化物沉积记录有关它们形成的流体的痕量元素组成以及降水时环境条件的关键信息；因此，痕量元件分布可以用作pH，氧化还原，温度和/或金属浓度等环境条件的代理。