Geochronological, Isotopic and Petrological Constraints on Magma Dynamics at Mt. Etna

埃特纳火山岩浆动力学的年代学、同位素和岩石学约束

• 批准号: 9614381
• 负责人: Frank Spera
• 金额: $ 8.1万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-03-15 至 2000-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9614381&HistoricalAwards=false
• 关键词: Geochronological; Isotopic; Petrological; Constraints; Magma

9614381 Spera This project will focus on constraining aspects of the magma geneses processes at one of the most active volcanoes in the world, Mt. Etna. Specifically, the study will concentrate on investigating correlations between alkali enrichments and dramatic changes in Sr and Pb isotopic composition. To assess whether these isotopic changes are more reasonably interpreted as the result of crustal contamination or mantle heterogeneity, samples from six historical flows will be studied with a combination of crystal size distribution analysis (CSD) and microsampling of phenocrysts and microphenocrysts. This technique will allow the documentation of how the isotopic composition of the materials change with crystal size. Common isotopic signatures are expected for phenocrysts and matrix if the variations in the chemistry of the magmas is the result of heterogeneity in the source. Alternatively, changes in isotopic composition associated with different crystal size distribution of phenocrysts would imply the importance of crustal contamination as a petrogenetic process.

9614381 Spera该项目将重点关注世界上最活跃的火山之一Mt.埃特纳。具体而言，这项研究将集中在调查碱富集和Sr和Pb同位素组成的急剧变化之间的相关性。为了评估这些同位素的变化是否更合理地解释为地壳污染或地幔异质性的结果，从六个历史流的样品将结合晶体粒度分布分析（CSD）和斑晶和microphenocrysts的微量取样进行研究。 这项技术将允许记录材料的同位素组成如何随晶体大小变化。 共同的同位素签名预计斑晶和矩阵，如果在岩浆的化学变化是在源的异质性的结果。另外，与斑晶的不同晶体尺寸分布相关的同位素组成的变化将暗示地壳混染作为成岩过程的重要性。