Collaborative Research: Residual Stress Preserved in Crystals from Volcanic Eruptions

火山喷发通过管道将岩浆从地下深处的水库输送到地表。 由于火山过程发生在地下，或者接近非常危险，火山爆发的许多关键方面很难通过直接观察进行研究。在这里，一种名为同步加速器X射线微衍射（microXRD）的新技术将用于记录火山爆发中运输的晶体中保存的变形。microXRD技术测量这些晶体的晶格中的应变量和保留应力。火山应力很重要，因为它们控制着喷发过程，包括岩浆运动和爆炸性。解释残余应力的第一步是确定使火山晶体产生应变的特定过程。为此，将进行火山模拟实验，使晶体变形。MicroXRD将用于分析实验产物，然后将结果与天然晶体进行比较。这组实验和测量将解决火山爆发的“如何”和“为什么”。该项目开发的标准和技术将使microXRD应用于其他学科，包括构造学，陨石学和材料科学。 作用在岩浆上的力控制着火山的过程。因此，来自火山爆发的晶体在岩浆房、管道和侵位过程中受到应变。同步加速器X射线微衍射（microXRD）将被用来量化这些应变的大小，通过分析晶格变形与亚微米空间分辨率的一套石英，磁铁矿，锆石晶体从长谷和黄石火山口。测量应变的大小并使用晶体的微观结构图将揭示应变如何在晶体中产生和保持。接下来，使用矿物的弹性常数和胡克定律将保留的应变转换为因果应力。其目标是量化不同火山环境中的火山应力，并评估这些力作用的力量和时间尺度。MicroXRD作为地质科学中的新兴技术具有非凡的潜力，但解释数据集的物理和理论基础设施有限。为此，将进行高温实验，使用未应变的合成晶体模拟火山环境中的应力，并评估应变天然晶体中的应力保持情况。实验产品将通过microXRD进行分析，并用于识别和/或消除变形源。

Volcanic eruptions transport magma from reservoirs deep underground to the surface through conduits. Because volcanic processes occur underground, or are very dangerous to approach, many key aspects of volcanic eruptions are difficult to study with direct observations. Here, a new technology called synchrotron X-ray micro diffraction (microXRD) will be used to document deformation preserved in crystals that were transported within volcanic eruptions. The microXRD technique measures the amount of strain and preserved stress in the crystal lattice of those crystals. Volcanic stresses are important because they control eruption processes, including magma movement and explosivity. The first step to interpreting residual stress is to identify the specific processes that strain volcanic crystals. To this end, volcanic simulation experiments will be performed to deform crystals. MicroXRD will be used to analyze the experimental products and then compare results with natural crystals. This set of experiments and measurements will address the "How" and "Why" of volcanic eruptions. The standards and techniques developed in this project will enable application of microXRD to other disciplines, including Tectonics, Meteoritics, and Materials Science. The forces that act on magmas control volcanic processes. Consequently, crystals from volcanic eruptions are strained in the magma chamber, conduit, and during emplacement. Synchrotron X-ray micro diffraction (microXRD) will be used to quantify the magnitude of those strains by analyzing crystal lattice deformation with submicron spatial resolution on a suite of quartz, magnetite, and zircon crystals from the Long Valley and Yellowstone calderas. Measuring the magnitude of strains and using microstructure maps across crystals will reveal how strain is produced and preserved in crystals. Next, the preserved strains will be translated to causal stresses using the elastic constants of the mineral and Hooke's law. The goal is to quantify volcanic stresses in different volcanic environments and assess the forces and the time scales over which those forces act. MicroXRD has exceptional potential as an emerging technology in the geological sciences, but there is limited physical and theoretical infrastructure to interpret datasets. For this reason, high-temperature experiments will be performed to simulate stresses in volcanic environments using unstrained synthetic crystals, and assess the preservation of stress in strained natural crystals. Experimental products will be analyzed by microXRD and used to identify and/or eliminate sources of deformation.