Collaborative Research: Incorporating Temperature-dependent Physical Properties into Numerical Models of Magmatic and Related Hydrothermal Systems

该奖项由2009年美国复苏和再投资法案（公法111-5）资助。地球内部的大多数地质过程都是由热传递驱动的。这些过程包括岩浆生成、火山作用、地热系统和几种类型矿床的生成。目前用于研究这些过程的数学和计算机模型通常假定岩石的几个基本性质为固定值，例如热容，即岩石保持热量的能力，热扩散率，即岩石传递热量的能力，以及熔化岩石所需的热量。许多类型岩石的这些属性值，特别是它们如何随温度变化，仍然知之甚少，研究的一个方面集中在实验室的实验测量上。然后，新的值将被应用于模拟地壳内特征良好的岩浆体通过持续或间歇性岩浆注入的生长，以及这些岩体的生长和结晶如何驱动周围岩石和地热系统的变质作用。该项目将提供机会，培训学生和青年科学家进行实验室、计算和实地研究。从多个角度观察复杂自然过程的能力是培养成功的地球科学家的关键。最近在理解花岗岩岩体如何构造方面取得的进展，促使人们需要改进岩石随温度变化的特性数据，以便将其纳入综合热模型。并且因为侵入引起的变质和地热系统通常具有比简单的传导和对流热模型通常预测的更长的持续时间。已经有了一个范式的转变，从将岩体视为大量的岩浆，这些岩浆在一个单一的脉冲中被注入作为底辟，到将岩体视为长时间生长的物体，从数万年到数百万年。岩浆的长期注入会影响岩体的结晶历史和变质地热系统的持续时间，所有这些都受热传递的控制。该项目的目的是确定矿物和岩石随温度变化的特性，并为岩浆-变质-地热系统建立综合数字模型。该模型将通过检查黑山哈尼峰花岗岩岩体的生长及其生长如何影响其热晕来进行实地测试。实验室的数据将对研究其他地质环境过程的工作人员有用。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Most geologic processes within the interior of the Earth are driven by heat transfer. These processes include magma generation, volcanism, geothermal systems, and generation of several types of ore deposits. Current mathematical and computer models used to study these processes generally assume fixed values for several fundamental properties of rocks such as heat capacity, that is the ability of rocks to hold heat, thermal diffusivity, that is the ability of rocks to transfer heat, and the amount of heat that is necessary to melt rocks. The values of these properties for many types of rocks, in particular how they vary with temperature, are still poorly known, and one aspect of the research focuses on experimental measurements in the laboratory. The new values will then be applied to modeling the growth of well-characterized magma bodies within the Earth's crust by continued or episodic magma injection, and how growth and crystallization of these plutons drives metamorphism of the surrounding rocks and geothermal systems. The project will provide an opportunity to train students and young scientists in research that will have laboratory, computational and field components. The ability to view complex natural processes from multiple perspectives is key to the training of successful geoscientists.The need for improved data on temperature-dependent properties of rocks that can be incorporated into integrated thermal models is motivated by recent advances in understanding of how granitic plutons are constructed, and because intrusion-induced metamorphic and geothermal systems generally have longer durations than simple conductive and convective thermal models typically predict. There has been a paradigm shift from viewing plutons as large volumes of magmas that are emplaced in a single pulse as diapirs to viewing plutons as bodies that grow over extended periods, from tens of thousands of years to millions of years. Prolonged injection of magma has consequences for crystallization histories of plutons and duration of metamorphic-geothermal systems, all of which are controlled by heat transfer. The aim of the project is to determine temperature-dependent properties of minerals and rocks and to develop integrated numerical models for magmatic-metamorphic-geothermal systems. The modeling will be field-tested by examination of the growth of the Harney Peak Granite pluton in the Black Hills and how its growth influenced its thermal aureole. The laboratory data will be useful to workers who study processes in many other geologic settings.