Experimental and Modeling Studies of the PVTX and Phase Equilibrium Properties of Crustal Fluids

地壳流体的PVTX和相平衡性质的实验和模拟研究

• 批准号: 1019770
• 负责人: Robert Bodnar
• 金额: $ 64.97万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1019770&HistoricalAwards=false
• 关键词: Experimental; Modeling; Studies; PVTX; Phase

Natural fluids that occur in the Earth affect many processes, including the formation of valuable ores of metals, the generation and accumulation of petroleum, the explosivity of volcanic eruptions, and can trigger large earthquakes. The compositions of these fluids vary widely depending on the environment in which they occur. Recent advances in the ability to analyze natural fluids from deep in the earth have shown that salts containing significant amounts of iron are common in fluids from many environments. In order to fully appreciate and understand the important role that iron-bearing fluids play in various geological processes, it is necessary to have a good understanding of the physical and chemical properties of the fluids over the range of temperatures, pressures and compositions representative of the different geological environments in which these fluids occur. This information, in turn, helps geologists to better explore for valuable metallic and energy resources required by modern society, and helps volcanologists and seismologists to better assess risks associated with volcanic eruptions and earthquakes.This project represents an experimental study to determine the phase equilibrium, volumetric and thermodynamic properties of fluids in the systems H2O-NaCl-CaCl2-FeCl2 and H2O-NaCl-KCl-FeCl2 over a range of pressure and temperature conditions appropriate to crustal magmatichydrothermal systems, and to develop numerical models to interpret microthermometric data obtained from natural fluid inclusions. This project represents a logical next step in improving our ability to understand increasingly more complex fluids that are representative of naturally occurring fluids. Specifically, this work will determine the location of the two-fluid phase field (i.e., limits of immiscibility) as a function of pressure, temperature and fluid composition (PTX), as well as the compositions of coexisting phases in the two-phase (liquid + vapor) field. The location of the critical point and the locus of P-T points along the critical isochore, isochores in the one-phase fluid fields, and low temperature phase equilibria required to interpret fluid compositions based on fluid inclusion microthermometry will also be determined. These new data will significantly advance current understanding of crustal magmatic hydrothermal systems and provide basic experimental data that may be used to estimate thermodynamic properties of complex aqueous fluids at elevated temperatures and pressures.

地球中存在的自然流体影响许多过程，包括有价值的金属矿石的形成、石油的产生和积累、火山喷发的爆发，并可能引发大地震。这些流体的成分根据它们所处的环境而有很大差异。分析地球深处天然流体能力的最新进展表明，含有大量铁的盐在许多环境的流体中很常见。为了充分认识和理解含铁流体在各种地质过程中发挥的重要作用，有必要充分了解流体在代表流体的温度、压力和成分范围内的物理和化学性质。这些流体发生的不同地质环境。这些信息反过来又可以帮助地质学家更好地探索现代社会所需的宝贵金属和能源资源，并帮助火山学家和地震学家更好地评估与火山喷发和地震相关的风险。该项目代表了一项确定相平衡的实验研究， H2O-NaCl-CaCl2-FeCl2 和 H2O-NaCl-KCl-FeCl2 系统中流体在适合地壳岩浆热液的压力和温度条件范围内的体积和热力学性质系统，并开发数值模型来解释从天然流体包裹体获得的微测温数据。该项目代表了提高我们理解代表自然存在的流体的日益复杂的流体的能力的合乎逻辑的下一步。具体来说，这项工作将确定两相场的位置（即不混溶极限）作为压力、温度和流体成分（PTX）的函数，以及两相中共存相的成分（液体+蒸气）场。还将确定沿临界等容线的临界点位置和 P-T 点轨迹、一相流体场中的等容线以及基于流体包裹体显微测温解释流体成分所需的低温相平衡。这些新数据将显着推进当前对地壳岩浆热液系统的理解，并提供可用于估计复杂水流体在高温和高压下的热力学性质的基本实验数据。