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

热液喷口是海底硫化物矿藏的重要来源，但人们对微量元素如何融入热流体及其相应的硫化物烟囱的过程知之甚少。该项目将测量天然热液喷口系统的流体烟囱对中的痕量元素浓度。 该项目的数据将增强我们对微量元素如何在流体和相应矿物之间转变的理解，并纳入旨在量化从热液喷口到深海的微量元素通量的研究以及侧重于块状硫化物形成和金属再活化的建模研究。该项目将支持本科生和研究生的培训，其结果将通过制作教育视频来广泛分享。过去，由于浓度极低，缺乏喷口流体和固体的微量元素数据，因此使用喷口流体和相应的烟囱衬里来测试分配假设受到了阻碍。最近使用改进的分析技术的努力使得痕量元素分配的研究成为可能。该项目将使用天然热液喷口系统来研究痕量元素从流体中分配到硫化物矿物中，这些矿物沿着烟囱管道的内衬沉淀，与热液喷口流体接触，在实验室难以重现的条件下。将对一组流体-烟囱对进行分析（同时对流体和烟囱进行采样）。该项目的数据和分析将用于检验以下两个假设：1）沿烟囱内衬从排放液中沉淀的矿物质以一种特有的方式结合了一些微量元素，其分配主要是元素浓度的函数，并且 pH、温度、氧化还原和配体浓度影响游离浓度与总浓度； 2) 海底硫化物沉积物记录了有关其形成的流体的微量元素组成以及沉淀时的环境条件的关键信息；因此，微量元素分布可用作环境条件（例如 pH、氧化还原、温度和/或金属浓度）的代理。

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.