Quantitative Investigation of Aqueous Organic Compounds in Ridge-Crest Hydrothermal Fluids

在大洋中脊的地壳中海水热液循环过程中，有机化合物在许多化学、物理和生物过程中发挥着重要作用。尽管它们很重要，但沉积的和未沉积的轴向温泉系统的热液中水有机物种的丰度和组成目前尚不清楚。在这项研究中，将使用新设计的气密流体采样器和潜水器Alvin在Juan de Fuca海脊北部的奋进和中谷热液油田采集热液流体。新的取样器允许在单个流体样本中定量测定挥发性和非挥发性水物种的丰度。将对流体进行广泛的水中有机和无机物种的定量分析，以全面描述地下化学环境并限制有机-无机化学相互作用的程度。这些结果将有助于更好地了解控制热液系统中有机物种产生和销毁的因素，并使人们能够评估广泛的生物地球化学过程，例如地壳蚀变、成矿金属的动员、从洋壳到水柱的碳通量、支持地下生物圈的营养物质的供应情况，以及可能是生命前体的有机化合物的非生物合成。

Organic compounds play an important role in numerous chemical, physical, and biological processes during circulation of seawater-derived hydrothermal fluids through the crust at mid-ocean ridges. Despite their importance, the abundance and composition of aqueous organic species in hydrothermal fluids from sedimented and unsedimented axial hot-spring systems are presently unknown. During this study, hydrothermal fluids will be sampled at the Endeavour and Middle Valley hydrothermal fields, northern Juan de Fuca ridge using a newly designed gas-tight fluid sampler and the submersible Alvin. The new sampler allows the abundance of both volatile and non-volatile aqueous species to be determined quantitatively in a single fluid sample. Fluids will be analyzed quantitatively for a broad spectrum of aqueous organic and inorganic species to fully characterize subsurface chemical environments and constrain the extent of organic-inorganic chemical interaction. The results will lead to an increased understanding of factors that regulate the generation and destruction of organic species in hydrothermal systems and allow evaluation of a broad spectrum of biogeochemical processes such as crustal alteration, mobilization of ore-forming metals, the flux of carbon from the oceanic crust to the water column, the availability of nutrients to support a subsurface biosphere, and the abiotic synthesis of organic compounds that may represent precursors to life.