Collaborative Research: Links Between Magma Source Characteristics, Shallow Plumbing, and Eruptive Styles in Mafic Intraplate Volcanic Fields (Lunar Crater Volcanic Field, Nevada)

合作研究：岩浆源特征、浅层管道和镁铁质板内火山田喷发类型之间的联系（内华达州月球陨石坑火山田）

• 批准号: 1016042
• 负责人: Elisabeth Widom
• 金额: $ 9.65万
• 依托单位: Miami University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1016042&HistoricalAwards=false
• 关键词: Collaborative; Research; Links; Between; Magma

Intellectual merit. Volcanoes that form in intraplate fields, although small and (mainly) monogenetic, result from eruptive phenomena ranging from quiet effusion of lava to relatively explosive Strombolian activity and, if external water interacts with ascending magma, hydrovolcanic activity. The generation and eruption of magmas in relatively small batches over dispersed areas, often with evidence for direct ascent from the upper mantle to the surface, suggests a driving process that is hybrid between strong hotspot-style mantle upwelling and scattered pockets of incipient melt that are passively mobilized by tectonic deformation (high- and low-magma flux end members of volcanic fields, respectively).Integrated approaches involving physical volcanology, petrology, and geochemistry can provide important insights into these processes and the links between magma dynamics at depth and eruption processes on the surface. The lack of long-lived crustal magma reservoirs) allows investigation of the influences of deep magma source(s) and shallow plumbing systems on eruption styles. It is hypothesized that eruption style is influenced by physical and chemical characteristics of magma sources. To test this hypothesis comprehensive data will be integrated from the well-exposed Lunar Crater Volcanic Field (central Nevada). Direct studies of eruptive facies, of exposed shallow conduits (at older, eroded volcanoes), and of abundant mantle xenoliths will provide insights into the magma sources and ascent processes. Existing data on broad geochemicsl trends and age relationships will be integrated with new EarthScope seismic tomography data to provide a framework for understanding: (1) the interplay between pre-existing structure, topography, and vent location; (2) shallow plumbing geometries; (3) shallow controls on magmatic eruption styles, including relationships between eruption style, clast texture and shape, volatile content, and mineral chemistry; (4) spatial and temporal variations in magma sources and magma differentiation processes at individual volcanoes and across the field as a whole; (5) depth of melting and volatile contents of parent magmas; and (6) correspondence between volcano location, melting depths, and upper mantle seismic structure.Broader impacts. This work will support improvements in volcanic risk assessment, both in terms of the probability (volcano timing and location) of future events and in terms of their consequences (related to eruption processes). The project will also support the training of three Ph.D. students (two of whom are female minorities) and will have a component of international collaboration with the volcanology and geochemistry group at the Universidad Autónoma de México. The proposing team is in communication both with the Shoshone Tribe (Duckwater Reservation) and the Bureau of Land Management so that we can share our results with them and (through BLM) with the public.

智力上的优点。形成于板内区域的火山，虽然很小，而且（主要）是单成因的，但都是由喷发现象引起的，从熔岩的平静流出到相对爆炸性的斯特龙博利活动，如果外部水与上升的岩浆相互作用，则是水火山活动。在分散的地区，相对小批量的岩浆的生成和喷发，通常有从上地幔直接上升到地表的证据，表明一个驱动过程是强烈的热点式地幔上涌和受构造变形被动动员的分散的初始熔体口袋之间的混合（分别为火山场的高和低岩浆通量端部成员）。综合方法涉及物理火山学，岩石学，地球化学可以提供重要的见解，这些过程和之间的联系，岩浆动力学的深度和喷发过程的表面。 缺乏长期的地壳岩浆库）允许调查的影响，深岩浆源（S）和浅管道系统的喷发风格。岩浆源区的物理和化学特征影响着岩浆的喷发方式。为了检验这一假设，将从暴露良好的月球火山口火山区（内华达州中部）综合综合数据。对喷发相、暴露的浅管道（在较老的侵蚀火山）和丰富的地幔捕虏体的直接研究将提供对岩浆来源和上升过程的深入了解。关于广泛的地球化学趋势和年龄关系的现有数据将与新的EarthScope地震层析成像数据相结合，以提供一个框架，用于了解：（1）先前存在的结构、地形和喷口位置之间的相互作用;（2）浅层管道几何形状;（3）岩浆喷发样式的浅部控制因素，包括喷发样式、碎屑结构与形态、挥发分含量和矿物化学;（4）岩浆源的时空变化和岩浆分异过程在个别火山和整个领域作为一个整体;（5）熔融深度和挥发性的母岩浆含量;（6）火山位置，熔融深度，和上地幔地震结构之间的对应关系。这项工作将有助于改进火山风险评估，包括未来事件的概率（火山爆发的时间和地点）及其后果（与喷发过程有关）。该项目还将支持培训三名博士。该项目将包括与梅西科自治大学火山学和地球化学小组的国际合作。提议小组与肖肖尼部落（达克沃特保留地）和土地管理局进行了沟通，以便我们能够与他们并（通过土地管理局）与公众分享我们的结果。