Collaborative Research: Volcanism on the Edge - Basaltic Volcanism from Source to Surface across the Colorado Plateau/Basin & Range Transition in SW Utah

合作研究：边缘火山活动 - 科罗拉多高原/盆地从源头到地表的玄武岩火山活动

• 批准号: 2152735
• 负责人: Greg Valentine
• 金额: $ 29.86万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2152735&HistoricalAwards=false
• 关键词: Collaborative; Research; Volcanism; Edge; Basaltic

The American Southwest is home to nearly forty basaltic volcanic fields that collectively contain more than 2,000 Quaternary volcanoes, including many that have erupted relatively recently (past 50,000 years). Most of these volcanoes are considered to be “monogenetic” (i.e., they erupt only once), and they generally produce relatively small volume eruptions (1 km3). Nevertheless, it has recently become clear that such eruptions can pose significant hazards due to their wide variety of eruptive styles, including explosive behavior, and the fact that the location of any future eruption is unknown. In the southwest US, neither the cause of this volcanism nor the frequency of recent eruptions is well understood. This project will focus on volcanism in SW Utah, in the transition between the Colorado Plateau and the Basin and Range provinces, an area that is particularly enigmatic with regard to the causes of volcanism, and poorly constrained with regard to the nature and frequency of recent volcanic activity. By integrating detailed field observations and mapping, radiometric dating, physical volcanology, and geochemical analyses, this project will provide key constraints on the sources, processes, and timescales of magma ascent and storage leading to eruption, and the link to eruptive style and hazards. In addition to providing information about hazards to the public, this work includes mentoring and training of two PhD students and several undergraduate researchers in field, analytical and imaging techniques. PIs will also engage in a variety of outreach activities related to the project, including research-based educational activities for K-12 students and teachers, public talks, and a summer course for middle and high school students.The Southwest US contains at least 2229 Quaternary volcanoes, most of which are monogenetic. Significant questions surround the causes and sources of the volcanism, the ages and eruptive recurrence intervals, and the range of – and controls on – eruptive styles. Understanding the processes that govern monogenetic volcanism in the Southwest US, and the time scales over which these processes operate, is critical for hazard and risk assessment. In addition, the mafic nature of many of these monogenetic volcanic fields makes them ideal as probes of the mantle sources that they tap, and spatial-temporal-compositional variations can thus provide a unique record of the complex tectonic history in this area. We propose an integrated physical volcanology and petrology/geochemistry study of Quaternary volcanism in the SW Utah volcanic field, spanning the transition from the Basin and Range to the Colorado Plateau, to elucidate links between tectonics, magma sources, and eruptive styles and hazards. Primary objectives include: 1) establishing age ranges and systematic age progressions, if extant; 2) evaluating the range of eruptive styles and associated hazards; 3) determining potential relationships of eruptive activity to local tectonic features; 4) constraining the nature (lithospheric vs. asthenospheric), location (depth), and spatial heterogeneity of the mantle sources tapped in the eruptions; 5) assessing the relative importance of mantle versus crustal control on magma composition and eruptive style, and the influence of magmatic water content; and 6) constraining timescales and the importance of magma storage systems in ascent from source to surface. Our integrated approach will involve detailed field mapping, 40Ar/39Ar dating, textural analysis of eruptive products, and elemental and isotopic analyses at both the whole-rock and mineral scales.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.

美国西南部拥有近 40 个玄武岩火山田，总共包含 2,000 多座第四纪火山，其中许多火山是最近才喷发的（过去 5 万年），其中大多数火山被认为是“单源火山”（即仅喷发）。一次），而且它们通常会产生相对较小的喷发量（1平方公里），然而，最近已经清楚的是，由于以下原因，此类喷发可能会造成重大危害。它们的喷发方式多种多样，包括爆炸行为，而且在美国西南部，未来喷发的地点尚不清楚，该项目将重点关注这次火山活动的原因和最近喷发的频率。犹他州西南部的火山活动，位于科罗拉多高原与盆地和山脉省份之间的过渡地带，该地区对于火山活动的成因尤其神秘，并且在最近火山活动的性质和频率方面缺乏约束。通过整合详细的实地观测和测绘、放射性测年、物理火山学和地球化学分析，该项目将为导致喷发的岩浆上升和储存的来源、过程和时间尺度以及与喷发类型的联系提供关键约束。除了向公众提供有关危害的信息外，这项工作还包括对两名博士生和几名本科生研究人员进行现场、分析和成像技术方面的指导和培训。项目，包括针对 K-12 学生和教师的基于研究的教育活动、公开演讲以及针对中学生和高中生的暑期课程。美国西南部至少有 2229 座第四纪火山，其中大部分是单生火山。火山活动的原因和来源、年龄和喷发复发间隔以及喷发类型的范围和控制，了解控制美国西南部单生火山活动的过程以及这些过程的时间尺度。此外，许多单成因火山田的镁铁质性质使其成为研究地幔来源的理想探针，因此时空成分变化可以提供独特的记录。我们提出了对犹他州西南部火山田第四纪火山活动进行综合物理火山学和岩石学/地球化学研究，跨越盆地和山脉的过渡。到科罗拉多高原，阐明构造、岩浆来源、喷发类型和危害之间的联系，主要目标包括：1) 确定喷发类型和系统年龄进展（如果存在）；2) 评估喷发类型和相关危害的范围； ) 确定喷发活动与当地构造特征的潜在关系； 4) 限制火山喷发的性质（岩石圈与软流圈）、位置（深度）和空间异质性；喷发中的地幔源；5) 评估地幔与地壳对岩浆成分和喷发方式的控制的相对重要性，以及岩浆含水量的影响；6) 限制时间尺度和岩浆储存系统在从源头上升的过程中的重要性。我们的综合方法将涉及详细的现场测绘、40Ar/39Ar 测年、喷发产物的结构分析以及全岩石和矿物尺度的元素和同位素分析。授予 NSF 的法定使命，并通过评估反映使用基金会的智力优点和更广泛的影响审查标准，被认为值得支持。