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

超级喷发是地球上最猛烈的火山喷发，它是由岩浆库提供的，这些岩浆库含有令人难以置信的大量富含二氧化硅的岩浆。在这些岩浆中形成并在其喷发产物中发现的晶体包含了关于导致这种毁灭性喷发的过程的重要信息。这个项目将研究硅质岩浆储集层的储存条件和动力学。7.4万年前，硅质岩浆储集层爆炸地喷发了巨大的最年轻的托巴凝灰岩(YTT)，然后在托巴火山口(印度尼西亚苏门答腊岛)平静地挤出了几个小的流纹岩熔岩穹顶。这些托巴岩浆含有不同寻常的石英晶团，可能记录了其宿主岩浆发展的重要证据。在其他破火山口形成的岩浆系统中的硅质火山岩中，石英团很少被识别或研究，因此将对TOBA石英团进行研究，以了解它们的起源及其对硅质岩浆演化和喷发潜力的影响。这项研究将在新加坡南洋理工大学的Caroline Bouvede Maisonneuve博士的指导下进行，Caroline Bouvede Maisonneuve博士是一位使用晶体尺度数据来确定岩浆储存条件和喷发动力学的专家。岩石学和阴极发光成像显示，石英聚集是影响YTT和熔岩穹顶晶体的40%-60%的重要过程。单个石英？单位的晶体取向？将获得集群内的数据，以确定集群形成的潜在机制，以及集群产生的环境类型。微量元素分析将用于对给定星团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，从而可能同时形成。这些结果将对Toba岩浆储集层的岩石学和流变学演化和动力学提供重要的限制，并有望突出从火山口前岩浆储存条件和喷发潜力向火山口后岩浆储存条件的过渡。TOBA石英团的特征也将与固化的地下岩浆体报告的特征进行比较，以深入了解火山岩与深成岩浆之间的联系。该NSF EAPSI奖是与新加坡国家研究基金会合作资助的。

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.