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.

地球上发生的天然流体会影响许多过程，包括形成有价值的金属矿石，石油的产生和积累，火山喷发的爆炸性以及可能引发大地震。这些流体的组成因发生的环境而差异很大。分析地球深处天然液体的能力的最新进展表明，含有大量铁的盐在许多环境的液体中很常见。为了充分欣赏和了解铁液在各种地质过程中发挥的重要作用，必须在温度，压力和组成范围内对流体的物理和化学性质有充分的了解，代表了这些流体发生的不同地质环境。反过来，这些信息可以帮助地质学家更好地探索现代社会所需的有价值的金属和能源资源，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。该项目代表了一项实验研究，以确定相位平衡，体积和热力学特性，在系统中的体积和热力学特性。 H2O-NACL-KCL-FECL2在适用于地壳岩层的压力和温度条件的范围内，并开发数值模型来解释从天然流体夹杂物获得的微热数据。该项目代表了提高我们了解代表自然流体的越来越复杂的流体的能力的逻辑下一步。具体而言，这项工作将确定两流体相位场（即不粘性的极限）的位置，这是压力，温度和流体组成（PTX）的函数，以及在两相（液体 + Vapor）场中共存相位阶段的组成。还将确定临界点的位置和p-t点的位置沿临界等距，一相流体场中的等位置位以及基于流体包含微量测量法的流体组成所需的低温相平衡。这些新数据将显着提高对地壳岩浆水热系统的当前理解，并提供基本的实验数据，这些数据可用于估算高温和压力下复杂水体流体的热力学特性。