Investigation of Apatite F-Cl-OH Solid Solution as a Monitorof Volatile Fugacities: Experimental Calibration and Applications to Volcanic Rocks

磷灰石群矿物是各类岩石中非常重要的副矿物。作为骨骼和牙齿的主要组成部分，它是医学领域大量研究的对象，并被商业开发用于许多重要用途。磷灰石的化学和结构相对简单，而且存在于非常广泛的岩石类型中，这使它有可能成为结晶环境中氟、氯和水相对活动的矿物学“监测仪”。建议在0.5 Kb压力和6000 ~ 900℃温度下，通过测定固溶体混合行为和评价端元热力学性质来校准这个“监视器”。这项研究所得的信息将在火成岩过程和火山现象、斑岩矿床的形成和变质流体组成的研究中具有重要的应用价值。获得的基本热力学数据可能在其他科学和化学工程中有潜在的应用。

Minerals of the apatite group are very important accessory minerals in all types of rocks. As a major constituent of bones and teeth it is the object of much research in the medical field, and is commercially exploited for a number of important uses. The relative chemical and structural simplicity of apatite and its occurrence in a very wide range of rock types make it potentially ideal as s mineralogical "monitor" of the relative activities of fluorine, chlorine and water in the environment in which it crystallized. It is proposed to calibrate this "monitor" by determining the solid solution mixing behavior and by evaluation of endmember thermodynamic properties with experiments at 0.5 Kb pressure, and temperatures between 600o and 900oC. The information to be derived from this study will have important applications in the study of igneous processes and volcanic phenomena, formation of porphyry ore deposits, and composition of metamorphic fluids. The fundamental thermodynamic data obtained may potentially have applications in other sciences and chemical engineering.