Pathways of Mineral Alteration and Organic Synthesis in Hydrothermal Systems on Mars

该奖项在火星岩石特别研究机会活动 支持热液矿物蚀变的理论评价 埃弗雷特L.地球的冲击与行星科学 华盛顿大学。 该项目由该办公室供资 极地计划，化学部，和MPS办公室 多学科活动。 火星陨石显示各向同性， 岩石学和矿物学证据表明， 火星地壳的变化 嗜热微生物的存在 在陆地热液生态系统中， 地下生命，独立于光化学，大气化学， 和表面水圈的存在，可能存在或已经存在于 其他星球上的热液环境 为了开发 火星地壳变化的预测模型，所有岩石学， 矿物和有机化合物的地球化学和同位素数据 ALH84001和其他军事陨石将被用来检查各种 碳酸盐矿物的形成途径，多环芳烃 碳氢化合物和其他有机化合物在水岩反应。 严格的地球化学质量迁移定量模型， 将使用不可逆热力学。 结果将决定 矿物开采所需的温度和流体成分的限制 改造和有机合成。 理论研究的最新进展 热液系统地球化学和正在进行的地球化学研究 生物能量学将用于开发模型。 这项研究将 涉及进行理论传质计算，模拟 含水流体与火星岩石成分的反应 陨石来确定温度和流体成分的范围 与碳酸盐矿物的沉积相一致， 形成含水硅酸盐相。 导致 碳酸盐沉积将与合成 从二氧化碳中提取有机化合物。 具体注意事项将 多环芳烃是否与 处于亚稳态氧化还原平衡的蚀变组合。 能够在陆地热液中生存的微生物的发现 这些条件提高了生命可能存在于类似 火星或其他行星上。 一个理论模型， 地质条件对有机合成的要求将是 开发 其结果将是对火星的潜力进行分析 支持热液生态系统。

This award in the Mars-Rock Special Research Opportunity activity supports theoretical evaluation of mineral alteration in hydrothermal systems by Dr. Everett L. Shock of the Earth and Planetary Science Department, Washington University. The project is funded by the Office of Polar Programs, the Chemistry Division, and the MPS Office of Multidisciplinary Activities. Martian meteorites show isotropic, petrological and mineralogic evidence for hydrothermal or aqueous alteration of the martian crust. The presence of thermaphilic microbes in terrestrial hydrothermal ecosystems raises the possiblity that subsurface life, independent of photochemistry, atmospheric chemistry, and the presence of a surface hydrosphere, may exist or have existed in hydrothermal environments on other planets. In order to develop a predictive model for crustal alteration on Mars, all petrologic, geochemical and isotopic data on minerals and organic compounds in ALH84001 and other martial meteorites will be used to examine various pathways for the formation of carbonate minerals, polycyclic aromatic hydrocarbons, and other organic compounds during water-rock reactions. Rigorous, quantitative models of geochemical mass transfer based on irreversible thermodynamics will be used. The results will determine the constraints on temperatures and fluid compositions required for mineral alteration and organic synthesis. Recent advances in the theoretical geochemistry of hydrothermal systems and ongoing research in geochemical bioenergetics will be used in developing the model. The research will involve conducting theoretical mass-transfer calculations that simulate the reactions of aqueous fluids with a rock of the composition of martian meteorites to establish the ranges of temperature and fluid composition consistent with the deposition of carbonate minerals without the formation of hydrous silicate phases. The conditions leading to carbonate deposition will be compared to those necessary for synthesis of aqueous organic compounds from carbon dioxide. Specific attention will be paid to whether polycyclic aromatic hydrocarbons are compatible with the alteration assemblage at metastable redox equilibrium. The discovery of microbes capable of living in terrestrial hydrothermal conditions raises the possibility that life may have existed in similar conditions on Mars or other planets. A theoretical model that compares geological conditions to the requirements for organic synthesis will be developed. The result will be an analysis of the potential for martian hydrothermal systems to support hydrothermal ecosystems.