Collaborative Research: High Field Strength Elements and Hf-Nd Isotope Systematics in Aleutian Lavas: Implications for Conservative Element Behavior in Subduction Zones

合作研究：阿留申熔岩中的高场强元素和 Hf-Nd 同位素系统学：对俯冲带保守元素行为的影响

• 批准号: 0230145
• 负责人: Gene Yogodzinski
• 金额: $ 13.9万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0230145&HistoricalAwards=false
• 关键词: Collaborative; Research; Field; Strength; Elements

Yogodzinski EAR-0230145This is a study of high field strength element (HFSE; Ti, Ta, Nb, Zr, Hf) and Lu-Hf isotopic systematics in volcanic rocks of the Aleutian island arc. The main objective of the study is to constrain the details of HFSE and related rare-earth element behavior in subduction zones. Specifically, the study will evaluate the conditions under-which HFSE behave conservatively versus non-conservatively during subduction magma genesis. High field strength element abundances and Hf-Nd isotopes will be measured in lavas collected from along the full length of the oceanic Aleutian arc. The analytical approach will involve (1) dissolution of samples in steel-jacketed Teflon vessels; (2) spiking of samples with a mixed 94Zr, 176Lu, 180Hf, 180Ta spike; (3) separation of elements of interest with ion-exchange chemistry; and (4) analysis of samples by isotope dilution on a multi-collector ICP mass spectrometer. This study will document along-arc and cross-arc changes in Aleutian HFSE and Hf isotope geochemistry. Well-documented changes in physical conditions along the arc, in particular the inferred relative temperature of the subducting plate and mantle wedge in the eastern versus western Aleutians, and the presence or absence of subducted sediment in the mantle source beneath different parts of the arc, will provide the geologic context for interpreting the observed HFSE and Hf isotopic variation.

Yogodzinski EAR-0230145这是一项对阿留申岛弧火山岩中高场强元素（HFSE；Ti、Ta、Nb、Zr、Hf）和 Lu-Hf 同位素系统学的研究。该研究的主要目的是限制俯冲带中 HFSE 和相关稀土元素行为的细节。具体来说，该研究将评估俯冲岩浆生成过程中 HFSE 表现保守与非保守的条件。将从阿留申大洋弧全长收集的熔岩中测量高场强元素丰度和 Hf-Nd 同位素。分析方法将涉及 (1) 在钢套聚四氟乙烯容器中溶解样品； (2)用混合的94Zr、176Lu、180Hf、180Ta加标样品； (3) 通过离子交换化学分离感兴趣的元素； (4) 在多接收器 ICP 质谱仪上通过同位素稀释对样品进行分析。这项研究将记录阿留申群岛 HFSE 和 Hf 同位素地球化学的沿弧和跨弧变化。沿弧的物理条件的变化有详细记录，特别是推断的东阿留申群岛和西阿留申群岛的俯冲板块和地幔楔的相对温度，以及弧不同部分下方的地幔源中是否存在俯冲沉积物，将为解释观测到的 HFSE 和 Hf 同位素变化提供地质背景。