Development of a Numerical Model for the PVTX Properties of Na-K-Ca-Fe-C1 Solutions in Magmatic/Hydrothermal Ore Deposits

将进行一项为期三年的实验研究，以确定与浅花岗岩岩浆相关的岩浆-热液矿床在合适的温度和压力范围内流体不混溶性的温度-压力-组成（PTX）极限。该研究将重点关注含有Na、K、Ca和Fe氯化物的水溶液中的流体成分，从含有Na-K、Na-Ca和Na-Fe氯化物的不太复杂的子系统开始。不混溶流体的样品将使用合成流体包裹体技术在原位捕获，流体的成分将使用标准的显微温度分析技术确定。这些成分数据将用于开发一个经验数值模型来预测岩浆热液过程中的P-T条件。该模型只需要在流体包裹体的常规显微测温和/或微化学分析过程中容易获得的信息。对水-氯化钠-氯化钾体系的初步研究证明了该项目的可行性。数据证实，合成流体包裹体捕获了在实验运行条件下存在的流体的代表性样品，并在淬火到环境实验室条件期间保持这些成分。此外，对共存的富液和富气包裹体进行常规显微测温分析可以确定流体成分。水- nacl - kcl体系的初步数据表明，共存的液体和蒸汽之间钠和钾的分配随温度和压力的变化而系统地变化。具体来说，随着温度的升高和压力的降低，钠在液相中的分配变得不那么明显。

BodnarEAR-0125918A three-year experimental study will be conducted to determine the temperature-pressure-composition (PTX) limits of fluid immiscibility over the temperature and pressure range appropriate for magmatic-hydrothermal ore deposits associated with shallow granitic magmas. The study will focus on fluid compositions in aqueous solutions containing Na, K, Ca, and Fe chlorides, starting with the less-complex sub-systems containing Na-K, Na-Ca, and Na-Fe chlorides. Samples of immiscible fluids will be trapped in situ using the synthetic fluid inclusion technique, and compositions of the fluids will be determined using standard microthermometric analytical techniques. The compositional data will be used to develop an empirical numerical model to predict P-T conditions attending magmatic-hydrothermal processes. The model will require only information that is easily obtainable during conventional microthermometric and/or microchemical analysis of fluid inclusions. The feasibility of the project has been documented by preliminary studies on the water-NaCl-KCl system. The data confirm that the synthetic fluid inclusions trap a representative sample of the fluid(s) present at experimental run conditions, and maintain these compositions during quenching to ambient laboratory conditions. Moreover, conventional microthermometric analysis of the coexisting liquid-rich and vapor-rich inclusions can be employed to determine the fluid compositions. Preliminary data for the water-NaCl-KCl system show that partitioning of sodium and potassium between coexisting liquid and vapor varies systematically with both temperature and pressure. Specifically, sodium partitioning into the liquid phase becomes less pronounced with increasing temperature and with decreasing pressure.