Modeling Magmatic Crystallization and Melting Behavior with Synthetic Water-Salt Fluid Inclusions

通过该项目，开发了一种使用合成H20-KCl流体包裹体的技术，以可视化地模拟岩浆结晶和熔融行为，供就读于高年级岩石学课程的学生使用。 该技术为学生提供了一个互动的，直观的学习经验的地质过程，永远不能直接观察。 使用已知成分的合成H2O-KCl流体包裹体和加热和冷却阶段，学生进行练习，观察和控制：（1）共晶熔化（冰和钾盐在-10.7 ℃），（2）液相线结晶和冰或钾盐的熔化，以及（3）最终冰或钾盐熔化温度。 使用这些数据，学生构建自己的H2O-KCl系统的富水部分的相图，然后将探索以下问题：（1）共晶和液相线温度与本体组成之间的关系;（2）在各种温度下的相规则的应用。 这种技术的主要优点是，所有重要的相变类似于岩浆系统（即，共晶和液相线行为、结晶和熔融织构）可以由学生直观地观察和控制。 因此，相图上的每一个空间、线和点都将与学生直接相关，并导致对相图及其在火成岩中的应用的更有意义的解释。

Through this project, a technique of using synthetic H20-KCl fluid inclusions is developed to visually simulate magmatic crystallization and melting behavior for students enrolled in an upper-division petrology course. The technique offers students an interactive, visual learning experience of a geologic process that can never be directly observed. Using synthetic H2O-KCl fluid inclusions of known composition and a heating and cooling stage, students conduct an exercise in which they observe and control: (1) eutectic melting (of ice and sylvite at -10.7 C), (2) liquidus crystallization and melting of ice or sylvite, and (3) final ice or sylvite melting temperatures. Using these data, students construct their own phase diagram of the water-rich portion of the H2O-KCl system and will then explore questions on the (1) the relationship between eutectic and liquidus temperatures and bulk composition and (2) applications of the phase rule at various temperatures. The main advantage of this technique is that all of the important phase changes analogous to magmatic systems (i.e., eutectic and liquidus behavior, crystallization and melting textures) can be visually observed and controlled by the student. Consequently, every space, line and point on a phase diagram will have direct relevance to the student and result in a more meaningful interpretation of phase diagrams and their application to igneous rocks.