Hydrous Components in Nominally Anhydrous Crustal Minerals

许多通常被配制为无水的矿物实际上含有低浓度的水或氢氧化物，这些水或氢氧化物结合在其结构中的不同部位。这些成分影响主相的性质，其程度与其实际浓度远远不成比例，并且共同构成了地球上全球重要的氢储存库。我们的研究计划旨在1）表征天然矿物和相关合成材料中这些组分的化学形式和浓度，2）将含水组分与宿主相的其他物理和化学性质联系起来，以及3）探索含水组分对陆地地质系统的意义。我们从几个地质事件中选择天然存在的矿物，并用各种光谱探针表征其含水组分。一个主要目的是确定主相中含水组分的定量。矿物中含水成分的一般特性提供了关于矿物系统中所含的全球蓄水池的基本信息，并提供了有关氢进入各种工业所用技术产品（合成矿物和相关结构）及其作用的信息。 需要绝对校准数据来限制各种矿物储层中氢的定量，这是评估挥发物在地球系统中的作用和运输的重要参数。 我们最终期望能够为地壳中发现的主要矿物群准备一般校准。无水矿物中这些成分的含量可能是地质系统中流体历史或流体变化的有用指标。 我们将致力于建立的程度和条件下，无水矿物保存在岩石中的水活动的记录，通过调查的OH在无水矿物在充分研究的地质环境，经历了不均匀的流体条件的变化。我们的研究结果将比较氧同位素系统学记录流体的历史，在同一矿物或岩石。通过详细的研究，我们将深入了解氧逸度等因素，这些因素可以改变OH和H2O在无水矿物结构中的保留。

RossmanEAR-0125767Many minerals that are usually formulated as anhydrous actually contain low concentrations of water or hydroxide bound in distinct sites in their structure. These components influence the properties of the host phase to an extent that is far disproportionate to their actual concentrations, and together, constitute a globally significant reservoir of hydrogen in planet Earth. Our research program is directed at 1) characterizing the chemical form and concentrations of these components in natural minerals and related synthetic materials, 2) relating the hydrous components to other physical and chemical properties of the host phases, and 3) exploring the significance of the hydrous components to the terrestrial geologic system. We select naturally occurring minerals from several geologic occurrences and characterize their hydrous components with a variety of spectroscopic probes. One major objective is to determine the quantitative amount of the hydrous components in the host phases. The general characterization of hydrous components in minerals provides basic information about the global water reservoir contained in minerals systems and provides information relevant to the entry and role of hydrogen into technological products (synthetic minerals and related structures) used in a variety of industries. The absolute calibration data is needed to constrain the quantitative amount of hydrogen in the various mineral reservoirs, an important parameter in evaluating the role and transport of volatiles in the Earth's systems. We ultimately expect to be able to prepare general calibrations for major groups of minerals found in the earth's crust.The content of these components in anhydrous minerals is potentially a useful indicator of fluid history or fluid variation within a geological system. We will work to establish the extent and conditions under which anhydrous minerals preserve a record of water activity in rock by investigating the variation of OH in anhydrous minerals in well-studied geological environments that have experienced inhomogeneous fluid conditions. Our results will be compared to oxygen isotope systematics that record fluid history in the same mineral or rock. Through detailed studies, we will gain insight into factors such as oxygen fugacity that could modify the retention of OH and H2O in anhydrous mineral structures.