Collaborative Research: Os, Nd and Hf isotopes in abyssal peridotites from Arctic Lena Trough: Continental lithospheric or asthenospheric mantle origin?

合作研究：北极勒拿海槽深海橄榄岩中的 Os、Nd 和 Hf 同位素：大陆岩石圈或软流圈地幔起源？

• 批准号: 0648409
• 负责人: John Lassiter
• 金额: --
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0648409&HistoricalAwards=false
• 关键词: Collaborative; Research; Os; Nd; Hf

(0648567/0648409 Snow/Lassiter)Intellectual Merit: This research seeks to use geochemical signatures in ultramafic ocean-basement rocks to understand the cause of continental breakups. Rocks collected on recent cruises to the Lena Trough, a young rift zone in the North Atlantic/Arctic separating the continental margins of European and North America will be analyzed and interpreted. Mineral separates from peridotitic mantle rocks from this amagmatic rift will be analyzed for the radiogenic isotopes Os, Re, Nd, and Hf to test whether there is an asthenospheric or continental lithospheric origin for the Lena Trough basement. If the rocks have a subcontinental source, the isotopes should show very low Os isotope ratios and scattered Nd and Hf values. Young asthenospheric origins will be reflected in uniformly young Nd and Hf model ages and Os isotopic compositions that match the average worldwide abyssal peridotite value.Broader Impacts: The project enhances the infrastructure for science by supporting new laboratories and equipment at two institutions. It also develops a new technique to measure Os isotopes via direct injection which improves on previous sparging methods. The work will expose undergraduates to research and train a graduate student. Efforts will be made to recruit try and recruit the graduate student from a group under-represented in the sciences.

(0648567/0648409 Snow/Lassiter)智力价值：这项研究旨在利用超镁铁质海洋基底岩石中的地球化学特征来了解大陆分裂的原因。 将分析和解释最近前往勒拿海槽的航行中收集的岩石，勒拿海槽是北大西洋/北极的一个年轻的裂谷带，分隔欧洲和北美的大陆边缘。我们将对来自该非岩浆裂谷的橄榄岩地幔岩石的矿物分离物进行放射性同位素 Os、Re、Nd 和 Hf 分析，以测试勒拿海槽基底是否存在软流圈或大陆岩石圈起源。 如果岩石有次大陆来源，同位素应显示非常低的 Os 同位素比和分散的 Nd 和 Hf 值。 年轻的软流圈起源将反映在一致的年轻 Nd 和 Hf 模型年龄以及与全球平均深海橄榄岩值相匹配的 Os 同位素组成中。 更广泛的影响：该项目通过支持两个机构的新实验室和设备来增强科学基础设施。它还开发了一种通过直接注射测量 Os 同位素的新技术，该技术改进了以前的喷射方法。 这项工作将使本科生参与研究并培养研究生。 我们将努力从科学领域代表性不足的群体中尝试招募研究生。