Collaborative Research: Organic Geochemical Investigation of the Rainbow Hydrothermal System, Mid-Atlantic Ridge

摘要：海底温泉中碳的命运对海洋地壳和水柱内发生的各种化学、物理和生物过程具有广泛的影响。然而，海底热液流体中有机化合物的组成和来源仍然知之甚少。因此，这项研究调查了彩虹热液系统中有机化合物的起源，该系统位于大西洋中脊的超镁铁质岩石中。之所以选择这个地点，是因为超镁铁质岩石可能在水性有机化合物的非生物合成中发挥关键作用，因为它们含有催化活性矿物质，并在与海水衍生的热液流体反应时产生还原性化学环境。将对彩虹热液中的气体和有机化合物及其伴生的硫化物矿物进行化学和同位素分析。特别分析将针对氨基酸、羧酸、氨和高分子量碳氢化合物。还将进行矿物和其他无机成分的地球化学分析。结果将使用热力学建模，并根据实验室实验进行解释，这将允许解释有机化合物的起源（非生物，热裂解，地幔脱气或微生物）。这项工作的更广泛影响包括伍兹霍尔海洋研究所和科罗拉多大学的学生的教育和培训，以及布里奇沃特州立学院理科学生的参与。这项工作还促进了与英国国家海洋学中心的国际合作，将其一名学生带到伍兹霍尔进行长期停留的项目工作。

ABSTRACT: Seewald/McCollum (0549829/0550800)The fate of carbon in submarine hot springs has broad implications for a diverse spectrum of chemical, physical, and biological processes occurring within the oceanic crust and water column. Nevertheless, the composition and source of organic compounds in submarine hydrothermal fluids remains poorly known. As a result, this research investigates the origin of organic compounds at the Rainbow hydrothermal system, which is hosted in ultramafic rocks on the Mid-Atlantic Ridge. The site was chosen because ultramafic rocks may play a pivotal role in the abiotic synthesis of aqueous organic compounds because they contain catalytically active minerals and create reducing chemical environments during reaction with seawater-derived hydrothermal fluids. Gases and organic compounds from Rainbow hydrothermal fluids will be analyzed chemically and isotopically, as will their associated sulfide minerals. In particular analyses will target amino acids, carboxylic acids, ammonia, and high molecular weight hydrocarbons. Geochemical analyses of minerals and other inorganic constituents will also be carried out. Results will be modeled using thermodynamics and interpreted in light of laboratory experiments that will allow interpretation of the origin (abiotic, thermal cracking, mantle degassing, or microbial) of the organic compounds. Broader impacts of this work include education and training of students at Woods Hole Oceanographic Institution and the University of Colorado, as well as engaging students who are under represented in the sciences from Bridgewater State College. The work also fosters international collaboration with the National Oceanographic Centre in the UK by bringing one of its students to Woods Hole to work on the project for an extended stay.