EAPSI: Understanding Crystal Cluster Origins in Magmas Erupted from Toba Caldera, Earth's Youngest Supervolcano

EAPSI：了解地球上最年轻的超级火山多巴火山口喷发的岩浆中晶簇的起源

• 批准号: 1514964
• 负责人: Olivia Barbee
• 金额: $ 0.51万
• 依托单位: Barbee Olivia A
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1514964&HistoricalAwards=false
• 关键词: EAPSI; Understanding; Crystal; Cluster; Origins

Supereruptions, the most violent volcanic eruptions on Earth, are fed by magma reservoirs that contain incredibly large volumes of silica-rich magma. Crystals formed within these magmas and found in their eruptive products contain important information on the processes that lead to such devastating eruptions. This project will investigate the storage conditions and dynamics of the silicic magma reservoir that explosively erupted the voluminous Youngest Toba Tuff (YTT) 74,000 years ago and then quiescently extruded several small rhyolite lava domes at Toba Caldera (Sumatra, Indonesia). These Toba magmas contain unusual quartz crystal clusters that likely record important evidence for the development of their host magma. Quartz clusters have seldom been recognized or studied in silicic volcanic rocks from other caldera-forming magma systems, and thus the Toba quartz clusters will be examined to understand their origin and the implications they have for silicic magma evolution and eruption potential. This research will be conducted at Nanyang Technological University in Singapore under the guidance of Dr. Caroline Bouvet de Maisonneuve, an expert on the use of crystal-scale data to determine magma storage conditions and eruption dynamics.Petrography and cathodoluminescence imaging reveal that quartz clustering is an important process affecting 40-60% of YTT and lava dome crystals. Crystallographic orientations of individual quartz ?units? within clusters will be acquired to identify potential mechanisms for cluster formation, as well as the type of environment from which they originated. Trace element analysis will be used to chemically fingerprint each unit in a given cluster to determine whether the individual units formed under similar magma conditions, and thus potentially at the same time. Results will provide important constraints on the petrological and rheological evolution and dynamics of the Toba magma reservoir and are expected to highlight a transition from pre- to post-caldera magma storage conditions and eruption potential. Toba quartz cluster features will also be compared to those reported from solidified subsurface magma bodies to provide insight on the connection between volcanic rocks and their plutonic counterparts. This NSF EAPSI award is funded in collaboration with the National Research Foundation of Singapore.

超级火山爆发是地球上最猛烈的火山爆发，由含有大量富含二氧化硅的岩浆的岩浆库提供。在这些岩浆中形成并在其喷发产物中发现的晶体包含导致这种毁灭性喷发的过程的重要信息。该项目将调查74，000年前大量最年轻的多巴凝灰岩（YTT）爆炸性喷发，然后在多巴火山口（印度尼西亚苏门答腊）平静地挤出几个小流纹岩熔岩圆顶的岩浆库的储存条件和动力学。这些多巴岩浆含有不寻常的石英晶体簇，可能记录了其寄主岩浆发展的重要证据。石英簇很少被认识到或研究在其他火山口形成的岩浆系统的火山岩，因此多巴石英簇将被检查，以了解它们的起源和它们对火山岩浆演化和喷发潜力的影响。这项研究将在新加坡的南洋理工大学进行，由Caroline Bouvet de Maisonneuve博士指导。Caroline Bouvet de Maisonneuve博士是利用晶体尺度数据确定岩浆储存条件和喷发动力学的专家。岩相学和阴极发光成像显示，石英成簇是影响40-60%的YTT和熔岩圆顶晶体的重要过程。单个石英的晶体取向？单位？将获得集群内部的信息，以确定集群形成的潜在机制以及它们起源的环境类型。微量元素分析将用于对给定集群中的每个单元进行化学指纹分析，以确定各个单元是否在类似的岩浆条件下形成，从而可能在同一时间形成。结果将提供重要的制约多巴岩浆库的岩石学和流变学的演化和动力学，并预计将突出从前到后破火山口岩浆储存条件和喷发潜力的过渡。鸟羽石英群的功能也将被比较，从凝固的地下岩浆体的报告，以提供火山岩和它们的深成对应物之间的连接洞察。这个NSF EAPSI奖是与新加坡国家研究基金会合作资助的。