Collaborative research: Assessing changes in the state of a magma storage system over caldera-forming eruption cycles, a case study at Taupo Volcanic Zone, New Zealand

合作研究：评估火山口形成喷发周期中岩浆储存系统状态的变化，新西兰陶波火山区的案例研究

• 批准号: 1654275
• 负责人: Adam Kent
• 金额: $ 20.05万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1654275&HistoricalAwards=false
• 关键词: Collaborative; research; Assessing; changes; state

The largest volcanic eruptions are rare events but can represent a global catastrophe. Smaller eruptions may still have significant (billions of dollars) economic impacts and may affect the lives and livelihoods of large numbers of people, even in places distant from the erupting volcano (e.g., the relatively small eruption in Iceland in 2010). This project focuses on the Taupo Volcanic Zone (TVZ) in New Zealand as a case study of a large and very active volcanic system, and will focus on developing a better understanding of how the temperature and mobility of a magma body below the surface changes before, during, and after a major eruption. This study will contribute to our understanding of the volcanoes that produce such large eruptions (for example, Yellowstone volcanic system in the US), and will provide critical context for interpretation of real-time hazard monitoring at these and other active volcanoes. In addition, the project will include research experience for a K-12 teacher and development of new standard-based physics, chemistry and mathematics curriculum that will be disseminated broadly.This ambitious project will develop a more complete understanding of the processes that govern the behavior of silicic magmatic systems, and, in particular, those that lead to the development of large, caldera-forming eruptions. This will be accomplished by a detailed study coupling age data with compositional data for both crystalline (plagioclase and zircon) and liquid (melt inclusions) parts of the erupted magma at the TVZ. These data will provide the foundation for a novel approach using two primary lines of investigation: 1) Constraints on the thermal history of pre-eruptive magma storage by coupling absolute ages for plagioclase crystal populations derived from U-series measurements with trace element diffusion models to constrain the maximum residence time of crystals at a given temperature; and 2) Quantification of the compositional heterogeneity of crystals and melt components, through in-situ measurements of trace-element and isotopic compositions in primary and accessory minerals and in melt inclusions (δ18O in zircon, εHf in zircon; Pb isotopes in plagioclase and melt inclusions), which will provide a measure of the degree to which the magma system is mixed across time and space within the reservoir as well as variations in the contributions of mantle and crustal sources to this reservoir. The unique strength of this approach is that it will allow simultaneous characterization of the thermal, compositional, and physical evolution of these silicic reservoirs. Therefore, the results of this study will be broadly relevant to other silicic volcanic systems and will represent an important step forward in improving our ability to interpret volcano monitoring data. Large silicic systems represent an end-member for volcanic activity globally, and more general models of the controls on the thermal conditions of magma storage beneath volcanoes will be developed by linking the results of this study with those from other ongoing projects.

最大规模的火山喷发虽然罕见，但却可能带来全球性灾难。较小的火山喷发仍可能产生重大（数十亿美元）的经济影响，并可能影响大量人的生活和生计，即使是在远离喷发火山的地方（例如，2010 年冰岛相对较小的火山喷发）。该项目重点关注新西兰陶波火山区（TVZ），将其作为一个大型且非常活跃的火山系统的案例研究，并将重点放在更好地了解地表以下岩浆体的温度和流动性在火山爆发之前如何变化。 、大喷发期间和之后。这项研究将有助于我们了解产生如此大规模喷发的火山（例如美国的黄石火山系统），并将为解释这些和其他活火山的实时灾害监测提供关键背景。此外，该项目还将包括 K-12 教师的研究经验，以及开发新的基于标准的物理、化学和数学课程，这些课程将被广泛传播。这个雄心勃勃的项目将更全面地了解控制行为的过程硅质岩浆系统，特别是那些导致大型火山喷发的岩浆系统。这将通过对 TVZ 喷发岩浆的结晶（斜长石和锆石）和液体（熔融包裹体）部分的年龄数据与成分数据进行详细研究来完成。这些数据将为使用两个主要研究方向的新方法奠定基础：1）通过将 U 系列测量得出的斜长石晶体群的绝对年龄与微量元素扩散模型结合起来，对喷发前岩浆储存的热历史进行限制限制晶体在给定温度下的最大停留时间； 2) 通过原位测量原生矿物和副矿物以及熔体包裹体中的痕量元素和同位素组成（锆石中的 18O，锆石中的 Hf），对晶体和熔体成分的组成异质性进行量化锆石；斜长石和熔体包裹体中的铅同位素），这将提供岩浆系统在储层内跨时间和空间混合的程度的测量以及地幔和地壳来源对该储层的贡献的变化。这种方法的独特优势在于，它可以同时表征这些硅质储层的热、成分和物理演化。因此，这项研究的结果将与其他硅质火山系统广泛相关，并将代表着在提高我们解释火山监测数据的能力方面向前迈出的重要一步。大型硅质系统代表了全球火山活动的终端成员，通过将本研究的结果与其他正在进行的项目的结果联系起来，将开发出更通用的火山下方岩浆储存热条件控制模型。

项目成果

The ion microprobe as a tool for obtaining strontium isotopes in magmatic plagioclase: A case study at Okataina Volcanic Centre, New Zealand

离子微探针作为获取岩浆斜长石中锶同位素的工具：新西兰奥卡泰纳火山中心的案例研究

• DOI: 10.1016/j.chemgeo.2019.03.016
• 发表时间: 2019
• 期刊: Chemical Geology
• 影响因子: 3.9
• 作者: Sas, May;Kawasaki, Noriyuki;Sakamoto, Naoya;Shane, Phil;Zellmer, Georg F.;Kent, Adam J.R.;Yurimoto, Hisayoshi
• 通讯作者: Yurimoto, Hisayoshi

Mush, Melts and Metasediments: a History of Rhyolites from the Okataina Volcanic Centre, New Zealand, as Captured in Plagioclase

糊状、融化物和变沉积物：斜长石中捕获的新西兰奥卡泰纳火山中心流纹岩的历史

• DOI: 10.1093/petrology/egab038
• 发表时间: 2021
• 期刊: Journal of Petrology
• 影响因子: 3.9
• 作者: Sas, May;Shane, Phil;Kuritani, Takeshi;Zellmer, Georg F;Kent, Adam J;Nakagawa, Mitsuhiro
• 通讯作者: Nakagawa, Mitsuhiro