The Lithosphere and Volcanic Processes: Isotopic Investigations

岩石圈和火山过程：同位素研究

• 批准号: 9218313
• 负责人: J. Douglas Macdougall
• 金额: $ 16.4万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-02-15 至 1997-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9218313&HistoricalAwards=false
• 关键词: Lithosphere; Volcanic; Processes; Isotopic; Investigations

Three separate tasks are planned. The first is an isotopic investigation of separated mineral phases from "ultradeep" ultramafic xenoliths from kimberlites. The second task is a geochemical and isotopic study of ultramafic xenoliths from several oceanic islands. The third task will be the major focus of our work. It entails development of laboratory capabilities for measuring 238U and 232Th isotopes by mass spectrometry, and will concentrate on the measurement of 226Ra in both whole-rock and separated phenocryst phases. The goal of his work is to gain a better understanding of the timescales and nature of magmatic fractionation processes, magma transport, and the origin of the ubiquitous 226Ra excesses in volcanic rocks from a variety of tectonic settings.

计划了三个独立的任务。首先是对来自金伯利岩的“超深”超基性捕虏体的分离矿物相进行同位素研究。第二项任务是对几个海洋岛屿的超镁铁质捕虏体进行地球化学和同位素研究。第三个任务将是我们工作的重点。它需要发展通过质谱法测量238U和232Th同位素的实验室能力，并将集中于测量整个岩石和分离斑晶相中的226Ra。他的工作目标是更好地了解岩浆分选过程的时间尺度和性质，岩浆运输，以及各种构造环境下火山岩中普遍存在的226Ra过量的起源。