Hydrocarbons in Hydrothermal Vent Fluids: Mineral Catalyzed Metastability of Reduced Carbon Compounds at Elevated Temperatures and Pressures

摘要：Seyfried（0549457）学术成就：这项研究利用新开发的热液流通反应器，限制了在超镁铁质海底热液系统中非生物生成碳氢化合物的碳还原反应的机制和速率，该反应器可以测量海底热液喷口高温高压下的反应。从大洋中脊喷口流出的热液为我们了解海水和洋壳的起源和演变提供了至关重要的线索。最近，超镁铁质热液系统的喷口流体已被发现含有丰富的和很大程度上意想不到的溶解烃类。该实验允许溶解气体（H2和CO2）和其他关键的水性物质被添加到含有矿物反应物（催化剂）的反应池中，同时从流出流体的有机化学变化中监测烃形成的速率和过程。 实验过程中溶解的H2浓度和pH（酸度）。通过在单程和再循环模式下进行实验，可以最大限度地减少有机污染，同时可以最大限度地增加矿物表面上的碳吸附，从而通过高分辨率表面分析技术（XPS，TOF-SIMS和C-XANES）促进矿物表面的分析。矿物催化剂将包括各种氧化物、硫化物和硅酸盐，这是超镁铁质热液系统海底下反应区的典型特征，这是从这些系统的喷口流体化学报告中推断出来的。 这项工作的更广泛的影响包括本科生通过UM/NSF REU地球流体研究的参与。该计划为来自传统本科院校的高成就学生提供支持，以参与实验设计和分析来自拟议调查的运行产品。它还将涉及开发拟议的带有现场化学传感器的热液流反应器。

ABSTRACT: Seyfried (0549457)Intellectual Merit: This research constrains the mechanism and rate of carbon reduction reactions that abiotically create hydrocarbons in ultramafic seafloor hydrothermal systems using a newly developed hydrothermal flow-through reactor that can measure reactions at the high temperatures and pressures present at hydrothermal vents in the seafloor. Hydrothermal fluids issuing from vents at mid-ocean ridges provide clues critical to our understanding of the origin and evolution of seawater and the oceanic crust through time. Recently, vent fluids from ultramafic-hosted hydrothermal systems have been found to contain abundant and largely unexpected dissolved hydrocarbon species. The experiments allow dissolved gases (H2 and CO2) and other key aqueous species to be added to a reaction cell that contains mineral reactants (catalysts), while rates and processes of hydrocarbon formation are monitored simultaneously from changes in the organic chemistry of the out-flow fluid. Dissolved H2 concentrations and pH (acidity) during the experiments. By performing experiments in both single pass and recirculation modes, organic contamination can be minimized, while carbon adsorption on mineral surfaces can be maximized, facilitating analysis of mineral surfaces by high-resolution surface analytical techniques (XPS, TOF-SIMS, and C-XANES). Mineral catalysts will include a wide range of oxides, sulfides and silicates typical of subseafloor reaction zones in ultramafic-hosted hydrothermal systems, as inferred from reported vent fluid chemistry from these systems. Broader impacts of the work include involvement of undergraduate students in research through the UM/NSF REU Fluids in the Earth. This program provides support for high achieving students from traditionally undergraduate institutions to join in the experimental design and analysis of run products derived from of the proposed investigation. It will also involve development of the proposed hydrothermal flow reactor with in-situ chemical sensors.