Coordinated Theoretical and Analytical Investigations of Organic Transformations During Diagenesis and Hydrothermal Alteration

9418500震荡尽管在表征地质流体的有机成分方面进行了大量研究，但对热的水溶液与自然过程中的有机物相互作用时发生转化的基本反应途径和机制仍然只有初步的了解。新兴的亚稳平衡范式提供了一个框架，在这个框架下，油田卤水和热液等地质流体中有机化合物之间的动态关系有助于更清楚地理解导致这些流体所观察到的组成的有机转化，并导致关于石油的起源、运输、聚集和蚀变的新观点。这项拟议的研究旨在扩大我们对亚稳态平衡态的了解，并提高它们对理解地球化学过程的适用性。建议研究中要解决的具体问题包括：亚稳态平衡态的广度。目前，亚稳平衡的争论主要基于油田卤水中的羧酸。天然溶液中还存在哪些有机化合物参与亚稳平衡状态，哪些不参与？特定的化合物家族是否达到亚稳定平衡，而其他的则不是？亚稳态平衡态的力学含义。所观察到的亚稳平衡关系能用来解释在自然环境中实际发生的反应途径吗？对催化剂的需求。所推断的途径需要催化剂的参与吗？在这些环境中有哪些催化剂，在什么情况下可以使用？微生物在多大程度上催化了这些反应？这些问题将通过一种协调理论计算与天然和实验溶液中有机溶质的采样和分析的方法来解决。这项工作将包括：1)收集和分析地质流体(最初是油田卤水)，以实现比目前可用的更全面的有机成分清单；2)将这些分析纳入新的亚稳态平衡测试，这将使我们能够识别哪些化合物参与了亚稳态平衡；3)使用这些计算的结果，确定有机化合物在自然环境中转化的途径；4)将这些结果与实验室研究进行比较，以确定哪些反应途径需要催化，以及5)开始寻找可能的催化剂。

9418500 Shock Despite the enormous amount of research that has gone into characterizing the organic composition of geologic fluids, there still remains only a rudimentary understanding of the fundamental reaction pathways and mechanisms by which transformation occur when hot aqueous solutions interact with organic matter in natural processes. The emerging paradigm of metastable equilibrium provides a framework with which the dynamic relationships among organic compounds in geologic fluids such as oilfield brines and hydrothermal solutions is leading to a clearer understanding of the organic transformations responsible for the observed composition of these fluids, and has lead to new ideas about the origin, transport, accumulation and alteration of petroleum. The proposed research seeks to expand our knowledge of metastable equilibrium states, and improve their applicability for understanding geochemical processes. Specific issues to be addressed in the proposed research include: The breadth of metastable equilibrium states. At present, metastable equilibrium arguments are based largely on carboxylic acids in oilfield brines. Which other organic compounds present in natural solutions participate in metastable equilibrium states, and which do not? Do specific families of compounds reach metastable equilibrium, while others do not? The mechanistic implications of metastable equilibrium states. Can the observed metastable equilibrium relationships be used to construe the reaction pathways that actually occur in natural settings? The need for catalysts. Do the inferred pathways require the participation of a catalyst? What catalysts are available in these environments and in what from? To what extent do microorganisms catalyze these reactions? These issues are to be addressed through an approach that coordinates theoretical calculations with sampling and analysis of organic solutes in natural and experimental solutions. This effort will include: 1) collection and analysis of geologic fluids (initially oil-field brines) to achieve a more thorough inventory of their organic composition than is presently available, 2) incorporating these analyses into new tests of metastable equilibrium which will allow us to identify which compounds participate in metastable equilibria, 3) using the results of these calculations, identify the pathways by which organic compounds are transformed in natural settings, 4) comparison of these results with laboratory studies to identify which reaction pathways require catalysis, and 5) initiating the search for likely catalysts.