Collaborative Research: Thermodynamics of Magma Mixing

合作研究：岩浆混合热力学

• 批准号: 1551052
• 负责人: Wendy Bohrson
• 金额: $ 21.1万
• 依托单位: Central Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-15 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1551052&HistoricalAwards=false
• 关键词: Collaborative; Research; Thermodynamics; Magma; Mixing

Molten rock (magma) forms at tens to hundreds of kilometers below Earth's surface. These magmas can ascend, and each year on Earth, about 30 cubic kilometers erupts or stalls, much of it within a few thousand meters of the surface. Transport and storage of magma in the crust (uppermost layer of the solid Earth) is associated with the formation of many strategically- and economically-important mineral resources including gold, platinum, chromium, diamonds and other gemstones and represents a source of untapped green energy called geothermal heat. The research carried out in this study advances infrastructural knowledge of how magmas evolve chemically and thermally through interactions with crust and as they cool, mix, and eventually solidify. Because all magmas initially contain small amounts of dissolved water and carbon dioxide, as magma cools and crystallizes, it often becomes a bubbly mixture containing high-pressure fugitive gas that can produce explosive eruptions, thereby posing risks to humans, property and ecosystems. This research seeks to better understand these phenomena based on the latest results from condensed matter physics, fluid mechanics, and chemical thermodynamics, all in the context of complex system behavior.Magma emplaced in the crust is a classic example of a complex, open system where magmas and crustal host rock exchange material and energy. The thermochemical evolution of magma subject to this exchange is responsible for much of the compositional diversity observed on Earth. This research applies chemical thermodynamics to predict from first-principles the products of magma crystallization and to relate these products to the amount of geothermal energy that flows to the environment. Open system magmatic behavior that emphasizes the consequences of complete blending of two distinct magma batches (a process called magma mixing) is modeled using two mass and energy constrained computational tools: an exploratory model that utilizes simplified mixing thermodynamics and a more complex model, called the Magma Chamber Simulator, that employs state of the art thermodynamics. Simulations using these codes will generate a theoretical magma mixing taxonomy that will classify thermal and chemical characteristics of mixing end-members and products. This taxonomy will be tested by applying it to carefully chosen volcanic and plutonic rock suites that show clear evidence of magma mixing. Analysis of mixed magma products will define mass and thermal consequences of mixing that can be used to refine models of eruption, magma emplacement, and mass and energy exchange from deeper to shallower levels in Earth. Both computer codes will be enhanced to better capture the open-system characteristics identified by these studies, and public distribution of these computer resources to the earth and planetary sciences community will augment computational analysis of magma formation and evolution. The ultimate end product of this research will be enhanced understanding of the transport, storage, and eruption of molten rock, an integral part of the planetary plate tectonic recycling process.

熔融岩石（岩浆）在地面表面以下几十至数百公里处形成。这些岩浆可以上升，每年在地球上，大约30立方公里爆发或摊位，其中大部分在表面几千米以内。岩浆在地壳中的运输和储存（固体地球的最高层）与许多战略性和经济上至关重要的矿物资源的形成有关，包括黄金，铂金，铬，钻石和其他宝石，代表了称为地热热的未开发的绿色能源的来源。在这项研究中进行的研究促进了基础设施知识，了解岩浆如何通过与外壳的相互作用以及冷却，混合并最终凝固的相互作用来化学和热发展。由于所有岩浆最初都包含少量溶解的水和二氧化碳，因为岩浆冷却和结晶，因此它通常变成含有高压逃亡气体的起泡混合物，可产生爆炸性喷发，从而对人类，财产和生态系统构成风险。这项研究旨在根据凝聚态物理学，流体力学和化学热力学的最新结果更好地理解这些现象，这都是在复杂的系统行为的背景下。地壳中放置的粘液是一个复杂，开放的系统的经典示例，其中岩浆和地壳宿主岩石交换材料和能量。岩浆的热化学演化受到这种交换的原因是在地球上观察到的许多组成多样性。这项研究应用化学热力学从第一原理预测岩浆结晶的产物，并将这些产品与流向环境的地热能的量相关联。开放的系统岩浆行为强调了两个不同的岩浆批次完全混合的后果（称为岩浆混合的过程）的后果是使用两个质量和能量约束的计算工具建模的：一种利用简化的混合热力学和一个更复杂模型的探索模型，称为岩浆腔室模拟器，采用了艺术热力学的状态。使用这些代码的仿真将产生理论上的岩浆混合分类法，该分类法将对混合终端成员和产品的热和化学特性进行分类。该分类法将通过将其应用于精心选择的火山和岩石岩套件来测试，以显示岩浆混合的明确证据。混合岩浆产物的分析将定义质量和混合的热后果，可用于完善喷发模型，岩浆增压，质量和能量交换，从地球中较深到较浅的水平。这两种计算机代码都将得到增强，以更好地捕获这些研究确定的开放系统特征，并且这些计算机资源向地球和行星科学社区的公共分布将增强岩浆形成和进化的计算分析。这项研究的最终最终产物将是对Molten Rock的运输，存储和喷发的理解，这是行星板块构造回收过程不可或缺的一部分。