Postglacial Tephra Chronology and Eruptive History of Mount Rainier, Washington

华盛顿州雷尼尔山冰期后的火山灰年代学和喷发历史

• 批准号: 9628575
• 负责人: James Vallance
• 金额: $ 6.46万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 2000-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9628575&HistoricalAwards=false
• 关键词: Postglacial; Tephra; Chronology; Eruptive; History

9628575 Vallance This study will focus on the dating and correlation of tephra layers and their association with downstream debris flows and pyroclastic flows with the goal of delineating the postglacial volcanic history of Mount Rainier and the behavior of the volcano during eruptive cycles. It will have as secondary goals the development and refinement of geochemical correlation techniques for andesitic tephras, and the magmatic evolution of the volcano during postglacial time at Mount Rainier volcano. The goals of the project will be met through traditional field methods and through geochemical fingerprinting and correlation techniques. Traditional methods include basic stratigraphy, radiocarbon dating, and component analysis of ferromagnesian minerals. Geochemical fingerprinting will be accomplished by analyzing whole rock and groundmass glass for major and trace elements and by microprobing groundmass glass and ferromagnesian minerals for major and minor elements then applying statistical analysis of similarity and variation coefficients to test possible correlations. The proposed study would greatly improve the hazard assessment at Mount Rainier by synthesizing stratigraphic sequences of past eruptions into genetic packages. Once understood, past eruptions can be used as models for potential behavior at the volcano if it becomes active.

9628575 Vallance这项研究将侧重于火山灰层的测年和相关性及其与下游泥石流和火山碎屑流的关系，目的是描绘雷尼尔山冰后期火山的历史和火山在喷发周期中的行为。 它的次要目标是安山质火山岩的地球化学相关技术的发展和完善，以及雷尼尔山火山在冰后期的火山岩浆演化。 该项目的目标将通过传统的实地方法和地球化学特征和相关技术来实现。 传统的方法包括基础地层学、放射性碳年代测定和铁镁矿物成分分析。 地球化学指纹将通过分析整个岩石和基质玻璃的主要和微量元素，并通过显微探测基质玻璃和铁镁矿物的主要和次要元素，然后应用相似性和变异系数的统计分析来测试可能的相关性。 拟议的研究将把过去爆发的地层序列综合成基因包，从而大大改进雷尼尔山的危险评估。 一旦了解，过去的爆发可以作为模型，在火山的潜在行为，如果它变得活跃。