Spatial Distribution, Longevity, and Evolution of Giant Magma Bodies: Tapping the Record in Crystal-rich Supereruptions

巨型岩浆体的空间分布、寿命和演化：挖掘富含晶体的超级喷发记录

• 批准号: 1830122
• 负责人: Guilherme Gualda
• 金额: $ 35.03万
• 依托单位: Vanderbilt University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1830122&HistoricalAwards=false
• 关键词: Spatial; Distribution; Longevity; Evolution; Giant

Supereruptions eject hundreds to thousands of km3 of magma into the air in a matter of days to months. They are the ultimate demonstration that the Earth's crust is capable of storing large quantities of eruptible magma. Not only are they a potential threat to humankind, but they are also fascinating from a scientific standpoint. Some of the largest eruptions on record seem to tap deposits that are crystal-rich, very extensive, and remarkably homogeneous in composition. In this project, the investigator will explore several important questions related to crystal-rich magma bodies that feed supereruptions: How is magma organized in the shallow crust just prior to supereruptions? What are the conditions that promote accumulation of unusually high amounts of eruptible magma in the shallow crust? How do magma systems that feed supereruptions evolve to a state that leads to a supereruption? What are the timescales over which these magma bodies differentiate, stall, and erupt? It is expected that the project will lead to new and improved understanding of the evolution of supereruption-forming magma bodies, including clues to the processes leading to eruption. It will provide support for graduate students at Vanderbilt University, whose graduate program has a strong record of training women in Earth & Environmental Sciences (at least two female PhD students will be funded by the project). The project will also support participation of undergraduates in research through participation in Vanderbilt May-term field courses abroad that the PI has been offering since 2013. The project will support work that will foster new and existing international and national collaborations.This study will combine four main approaches: (1) Study of the spatial distribution of magmas using the geographic distribution of vents and other surface manifestations of magma localization (e.g. collapse areas), in combination with information from geobarometry, which will inform the depth at which magmas are stored; (2) The depths of magma extraction will be a focus of study using geobarometry to assess to what extent storage of eruptible magma takes place contiguously with crystal-rich material from which it is extracted; (3) The crystallization times of eruptible magmas will be investigated using geospeedometry of major and accessory phases; (4) The evolution of magmas will be explored combining the record preserved in rock textures, crystal zoning, and glass compositions with information that can be extracted from thermodynamic modeling using rhyolite-MELTS, including investigations of the processes that control magma eruptibility. Two main localities were selected for the detailed work: (a) Ora Caldera deposits in northern Italy; and (b) Whakamaru Group in the Taupo Volcanic Zone, New Zealand.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

超级火山爆发会在几天到几个月的时间内将数百到数千公里的岩浆喷射到空气中。它们是地壳能够储存大量可喷发岩浆的终极证明。它们不仅是对人类的潜在威胁，而且从科学的角度来看，它们也很迷人。有记录以来的一些最大规模的喷发似乎是利用了富含晶体的沉积物，这些沉积物非常广泛，组成也非常均匀。在这个项目中，研究人员将探索与超级火山爆发的富含晶体的岩浆体有关的几个重要问题：超级火山爆发之前，岩浆是如何在浅层地壳中组织起来的？是什么条件促使浅层地壳中异常大量的可喷发岩浆积聚？为超级火山喷发提供养分的岩浆系统是如何演变成导致超级火山喷发的状态的？这些岩浆体分化、停滞和喷发的时间尺度是什么？预计该项目将导致对超级喷发形成岩浆体演化的新的和改进的理解，包括导致喷发过程的线索。它将为范德比尔特大学（Vanderbilt University）的研究生提供支持，该校的研究生项目在培养地球与环境科学领域的女性方面有着良好的记录（该项目将资助至少两名女性博士生）。该项目还将通过参与范德比尔特大学自2013年以来提供的5学期海外实地课程，支持本科生参与研究。该项目将支持将促进新的和现有的国际和国家合作的工作。本研究将结合以下四种主要方法：(1)利用火山口的地理分布和岩浆定位的其他地表表现（如崩塌区）来研究岩浆的空间分布，并结合地球气压测量的信息来确定岩浆的储存深度；(2)岩浆提取深度将是利用地球气压法研究的重点，以评估可喷发岩浆在多大程度上与提取的富含晶体的物质相邻储存；(3)利用主相和副相速度法研究可喷发岩浆的结晶时间；(4)结合岩石结构、晶体分带和玻璃成分记录，结合流纹岩熔体热力学建模提取的信息，探索岩浆的演化，包括控制岩浆喷发的过程。选定了两个主要地点进行详细工作：(a)意大利北部的Ora Caldera矿床；(b)新西兰陶波火山区的Whakamaru群。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

The Whakamaru magmatic system (Taupō Volcanic Zone, New Zealand), part 1: Evidence from tephra deposits for the eruption of multiple magma types through time

华卡马鲁岩浆系统（新西兰陶普火山带），第 1 部分：来自火山灰沉积物的证据表明多种岩浆类型随着时间的推移喷发

• DOI: 10.1016/j.jvolgeores.2023.107966
• 发表时间: 2024
• 期刊: Journal of Volcanology and Geothermal Research
• 影响因子: 2.9
• 作者: Harmon, Lydia J.;Gualda, Guilherme A.R.;Gravley, Darren M.;Smithies, Sarah L.;Deering, Chad D.
• 通讯作者: Deering, Chad D.

The Whakamaru Magmatic System (Taupō Volcanic Zone, New Zealand), part 2: Evidence from ignimbrite deposits for the pre-eruptive distribution of melt-dominated magma and magma mush

华卡马鲁岩浆系统（新西兰陶普火山带），第 2 部分：来自火凝灰岩沉积物的证据，表明喷发前以熔体为主的岩浆和岩浆糊的分布

• DOI: 10.1016/j.jvolgeores.2024.108013
• 发表时间: 2024
• 期刊: Journal of Volcanology and Geothermal Research
• 影响因子: 2.9
• 作者: Harmon, Lydia J.;Smithies, Sarah L.;Gualda, Guilherme A.R.;Gravley, Darren M.
• 通讯作者: Gravley, Darren M.

Following magma: The pathway of silicic magmas from extraction to storage during an ignimbrite flare-up, Taupō Volcanic Zone, New Zealand

跟随岩浆：在新西兰陶普火山区火成岩爆发期间，硅质岩浆从提取到储存的路径

• DOI: 10.1016/j.epsl.2023.118053
• 发表时间: 2023
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Smithies, Sarah L.;Harmon, Lydia J.;Allen, Sydney M.;Gravley, Darren M.;Gualda, Guilherme A.R.
• 通讯作者: Gualda, Guilherme A.R.