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。热液蚀变的洋壳提供了在大洋中脊和俯冲带的热液循环期间发生的海水和地幔之间的热量和质量转移的记录。产生蛇纹石矿物的热液喷口系统与富含有机物的碱性流体有关，是海底微生物生命产生能量供应的核心。本研究使用硼，锶，钕元素的浓度以及硼同位素分馏研究的作用，在转换的橄榄岩和其他超镁铁岩常见的海底和下地壳的蛇纹石和其他矿物的水岩反应。这项工作涉及新颖的，受控的，热液，实验室实验，研究pH值，温度和矿物成分控制硼同位素分馏和组合的B-Sr-Nd流动性和岩石流体交换。选择目标地球化学元素是因为它们是温度和流体pH值条件的记录器，并允许将实验结果应用于化石热液系统和相关矿床。此外，这些测量将限制低温蛇纹化对火山弧元素循环效率的影响，并增强我们对俯冲板块影响岛弧火山岩的地球化学通量的理解。工作的更广泛的影响是两个早期职业研究人员的支持，促进新的合作，学生的支持，国际合作，并在EPSCoR国家机构的支持

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