Collaborative Research: Serpentinization and cycling of B, Nd and Sr in submarine hydrothermal systems: An experimental study on the effects of pH and temperature

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。热液改变的海洋地壳提供了在洋中脊和俯冲带热液循环期间海水和地幔之间的热量和质量传递的记录。产生矿物蛇纹石的热液喷口系统与富含有机物的碱性流体有关，并且是为海底微生物生命提供能量供应的核心。本研究使用硼、锶和钕元素浓度以及硼同位素分馏来研究水岩反应在海底和下地壳中常见的橄榄岩和其他超镁质岩石向蛇纹石和其他矿物转化中的作用。这项工作包括新的、可控的热液、实验室实验，研究pH、温度和矿物成分对硼同位素分馏的控制，以及B-Sr-Nd的联合迁移性和岩石-流体交换。之所以选择目标地球化学元素，是因为它们是温度和流体pH条件的记录者，可以将实验结果应用于化石热液系统和伴生矿床。此外，这些测量结果将限制低温蛇纹岩化对跨火山弧元素再循环效率的影响，并增强我们对俯冲板块影响岛弧火山的地球化学通量的理解。这项工作的更广泛影响是支持两名早期职业研究人员，促进新的合作，支持学生，国际合作以及支持EPSCoR州的机构

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Hydrothermally altered ocean crust provides a record of heat and mass transfer between seawater and the earth's mantle that takes place during hydrothermal circulation at mid ocean ridges and subduction zones. Hydrothermal vent systems that generate the mineral serpentine are linked to alkaline fluids enriched in organics and are central to generating the energy supply for microbial life at the seafloor. This research uses boron, strontium, and neodymium elemental concentrations as well as boron isotope fractionation to examine the role of water-rock reaction in the conversion of peridotites and other ultramafic rocks common on the seafloor and in the lower crust to serpentine and other minerals. The work involves novel, controlled, hydrothermal, laboratory experiments that examine the pH, temperature and mineral composition controls on boron isotope fractionation and combined B-Sr-Nd mobility and rock-fluid exchange. Targeted geochemical elements were picked because they are recorders of temperature and fluid pH conditions and allow application of the results of the experiments to fossil hydrothermal systems and associated ore deposits. Furthermore, the measurements will constrain the effects of low-temperature serpentinization on the efficiency of elemental recycling across volcanic arcs and enhance our understanding of geochemical fluxes from subducting slabs which impact island arc volcanics. Broader impacts of the work are support of two early career researchers, promotion of a new collaboration, support of students, international collaboration, and support of an institution in an EPSCoR state