The Record of Recharge, Assimilation, and Storage in the Popocatepetl Magma System from Sr Isotopes and Glass Inclusions in Phenocrysts and Experimental Petrologic Constraints

波波卡特佩特尔岩浆系统中斑晶中锶同位素和玻璃包裹体的补给、同化和储存记录以及实验岩石学约束

• 批准号: 0711043
• 负责人: James Gardner
• 金额: $ 25.44万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0711043&HistoricalAwards=false
• 关键词: Record; Recharge; Assimilation; Storage; Popocatepetl

Intellectual merit. Explosive silicic volcanism poses a major societal threat, yet the underlying causes for large Plinian eruptions remain unclear. Several contributing factors include [1] the relative contributions of different processes (e.g., fractional crystallization, recharge by new magma, interaction of magma and wall rocks) that control volumes and compositions of magma reservoirs, [2] the role of volatile components (e.g., H2O, CO2, S, Cl, F) in controlling magma properties and exsolution of a separate fluid phase, and [3] temporal variations in the geometry of magma plumbing systems. A detailed study of Popocatepetl volcano, located on the fringe of Mexico City, is proposed to evaluate temporal variations and how these factors correlate with eruptive style over the past 23,000 years of activity (as deciphered from tephrochronology records). During this period, at least seven significant Plinian eruptions of dramatically different volumes have occurred. The eruptive products will be characterized to unravel magma evolution and volatile contents, primarily via detailed study of individual phenocrysts and trapped melt inclusions therein using multiple quantitative analytical methods (electron microprobe, laser ablation ICPMS, FTIR) and experimental simulations.Broader impacts. The project will support two Ph.D. students, one of whom is a Mexican national, and several undergraduate students. The project will also benefit from direct collaboration with Dr. Claus Siebe (UNAM, Mexico city), who has documented the eruptive history of the volcano via detailed tephrochronology work in the region. This collaboration will result in significant technology transfer between the US and Mexico, and will undoubtedly contribute to understanding of volcanic hazards in the area.

智力上的优点。硅质火山喷发构成了重大的社会威胁，但普林尼亚大喷发的根本原因尚不清楚。几个促成因素包括：[1]控制岩浆储集层体积和组成的不同过程(例如，分离结晶、新岩浆补给、岩浆与围岩的相互作用)的相对贡献，[2]挥发性组分(例如，H2O、CO2、S、氯、F)在控制岩浆性质和单独的流体相出溶方面的作用，以及[3]岩浆管道系统几何形状的时间变化。建议对位于墨西哥城边缘的Popocatepetl火山进行详细研究，以评估时间变化以及这些因素与过去23,000年来活动方式(从年代学记录中破译)的相关性。在此期间，至少发生了7次规模截然不同的重大普林尼安火山喷发。喷发产物的特征是揭示岩浆演化和挥发分含量，主要是通过使用多种定量分析方法(电子探针、激光烧蚀ICPMS、FTIR)和实验模拟对单个斑晶和捕获的熔体包裹体进行详细研究。该项目将支持两名博士生，其中一名是墨西哥人，以及几名本科生。该项目还将受益于与Claus Siebe博士(墨西哥城大学)的直接合作，他通过该地区详细的火山年代学工作记录了火山喷发的历史。这一合作将导致美国和墨西哥之间的重大技术转让，并无疑将有助于了解该地区的火山灾害。