Geochemistry and Petrologic Evolution of Felsic Volcanoes in Western Marie Byrd Land, Antarctica

南极洲西玛丽伯德地长英质火山的地球化学和岩石学演化

• 批准号: 0536526
• 负责人: Wesley Le Masurier
• 金额: $ 3.53万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0536526&HistoricalAwards=false
• 关键词: Geochemistry; Petrologic; Evolution; Felsic; Volcanoes

This project uses geochemical studies to determine the origin of volcanic rocks from Marie Byrd Land (MBL), Antarctica. Surprisingly, adjacent volcanoes in the MBL have dramatically different compositions, ranging from phonolite to trachyte to rhyolite. This diversity offers an opportunity to constrain the processes responsible for generating silica oversaturated and undersaturated magmas in a single geologic setting. Previous work suggests that the most obvious and simplest explanation--crustal contamination--is not a significant factor, and that polybaric fractional crystallization is the major cause. This study evaluates these factors through analyses and interpretation of trace and rare earth element abundances, as well as Sr and Nd isotopic ratios. The broader impacts include outreach programs to the Girl Scouts of America, and dissemination of results through publications and meetings.

该项目利用地球化学研究来确定南极洲玛丽伯德地（MBL）火山岩的起源。令人惊讶的是，MBL中相邻的火山具有显著不同的成分，从响岩到粗面岩再到流纹岩。这种多样性提供了一个机会，以限制负责在一个单一的地质环境中产生二氧化硅过饱和和不饱和岩浆的过程。以前的工作表明，最明显和最简单的解释-地壳污染-不是一个重要因素，而多压分离结晶是主要原因。本研究通过分析和解释微量元素和稀土元素丰度以及Sr和Nd同位素比值来评估这些因素。更广泛的影响包括对美国女童子军的外联方案，以及通过出版物和会议传播成果。