Volcanoes Erupt Stressed Quartz Crystals
Volcanoes Erupt Stressed Quartz Crystals
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DOI：
10.1029/2019gl083619
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发表时间：
2019-07
影响因子：
5.2
通讯作者：
K. Befus;M. Manga;C. Stan;N. Tamura
中科院分区：
文献类型：
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作者：
K. Befus;M. Manga;C. Stan;N. Tamura
火山爆发是岩浆力量不平衡导致的能量事件。这些部队的规模仍然没有得到很好的限制，因为它们在无法进入的地区活动，要么是在地下，要么是接近起来很危险。需要新技术来量化驱动喷发的过程，并探测岩浆储存条件。在这里，我们提出了火山应力的X射线微衍射测量，这些应力以晶格畸变的形式传递给来自黄石和长谷火山喷发的岩浆晶体货物。在喷发的石英中保留了100 - 300mpa的高残余应力。多种火山力量可能是造成这种变形的罪魁祸首，因此我们分析了来自火山碎屑坠落、火山碎屑密度流和喷涌熔岩的晶体。应力保存在所有石英中，但不能归因于喷发方式的差异。相反，晶格变形可能保留了在上升过程中粘性含晶玻璃脆性破坏所需的偏应力的原位测量。
Volcanic eruptions are energetic events driven by the imbalance of magmatic forces. The magnitudes of these forces remain poorly constrained because they operate in regions that are inaccessible, either underground or dangerous to approach. New techniques are needed to quantify the processes that drive eruptions and to probe magma storage conditions. Here we present X‐ray microdiffraction measurements of volcanic stress imparted as lattice distortions to the crystal cargo of magma from Yellowstone and Long Valley eruptions. Elevated residual stresses between 100 and 300 MPa are preserved in erupted quartz. Multiple volcanic forces could be culpable for the deformation so we analyzed crystals from pyroclastic falls, pyroclastic density currents, and effusive lavas. Stresses are preserved in all quartz but cannot be attributed to differences in eruption style. Instead, lattice deformation likely preserves an in situ measurement of the deviatoric stresses required for the brittle failure of viscous, crystal‐bearing glass during ascent.