Hydrous Components in Nominally Anhydrous Minerals

Rossman许多矿物名义上是无水的，实际上含有低浓度的水或氢氧化物，结合在它们结构的不同位置。这些组分影响宿主相的性质，其程度与它们的实际浓度远远不成比例，它们共同构成了地球上具有全球意义的氢的储存库。我们的研究计划旨在1)表征这些组分在天然矿物和相关合成材料中的化学形态和浓度，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。我们从各种地质产状中选择自然存在的矿物，并用红外光谱表征它们的水合成分。然后我们的样品子集将被准备用于核轮廓分析，该分析可以确定绝对氢含量。将为在地壳和地幔中发现的主要矿物质群准备工作曲线。在受控温度和压力条件下生长的已知化学成分的合成矿物将为检验化学成分对含水成分的影响提供标准。它们还将涉及将从天然矿物获得的信息与其形成条件联系起来的目标。

9804871RossmanMany minerals which are nominally 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 toan 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 a variety of geologic occurrences and characterize their hydrous components with infrared spectroscopy. A subset of our samples will then be prepared for Nuclear Profile Analysis which can determine the absolute hydrogen content. Working curves will be prepared for major groups of minerals found in both Earths crust and mantle. Synthetic minerals grown under controlled temperature and pressureconditions and with known chemical components will provide standards for examining the influence of chemical composition upon the hydrous components. They also will address the objective of relating information obtained from natural minerals to their conditions of formation.