Experimental Study of Iron Partitioning and Hydrogen Generation During Serpentinization of Ultramafic Rocks

超镁铁岩蛇纹石化过程中铁配分与产氢实验研究

• 批准号: 0927744
• 负责人: Thomas McCollom
• 金额: $ 44.51万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0927744&HistoricalAwards=false
• 关键词: Experimental; Study; Iron; Partitioning; Hydrogen

Scientists have become increasingly aware of microbial communities living at and below the seafloor where they thrive on chemical energy (chemosynthesis) rather than sunlight. While it is not yet known how abundant and widespread such chemosynthetic communities are, it has been suggested that they may make significant contributions to global biomass and the biogeochemical cycles of carbon and other elements. A primary source of chemical energy that sustains these deep sea microbes is molecular hydrogen (H2), which is generated from the reaction of water with ultramafic rocks, a process known as serpentinization. However, the factors that control the amount of hydrogen generated during serpentinization remain poorly known. This research conducts laboratory experiments at high temperatures and along the vapor pressure curve of H2O that monitor H2 production as water-rock reactions proceed as a way to simulate the serpentinization process. Detailed analysis of the solid reaction products with state-of-the-art high resolution methods make it possible to define the chemical reactions that generate hydrogen. Numerical geochemical models will provide a framework for extrapolating the laboratory results to natural systems. Broader impacts of the work include training for a postdoctoral associate and two undergraduate students. The research will also serve as a focal point for a new university course aimed at training students in a multidisciplinary scientific approach.

科学家们越来越意识到生活在海底和海底的微生物群落，在那里它们依靠化学能量(化学合成)而不是阳光茁壮成长。虽然目前尚不清楚这种化学合成群落的丰富性和广泛性，但有人认为，它们可能对全球生物量以及碳和其他元素的生物地球化学循环做出重大贡献。支持这些深海微生物的主要化学能量来源是分子氢(H2)，它是由水与超镁铁质岩石反应产生的，这一过程被称为蛇纹岩作用。然而，控制蛇纹化过程中产生的氢气量的因素仍然鲜为人知。这项研究在高温下沿着H2O的蒸汽压曲线进行实验室实验，监测水-岩石反应过程中H2的产生，作为模拟蛇纹岩作用过程的一种方式。使用最先进的高分辨率方法对固体反应产物进行详细分析，使定义产生氢的化学反应成为可能。数值地球化学模型将为将实验室结果外推到自然系统提供一个框架。这项工作的更广泛影响包括培训一名博士后助理和两名本科生。这项研究还将作为一门新的大学课程的焦点，旨在培训学生采用多学科的科学方法。