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

（0648567/0648409 Snow/Lassiter）学术成就：这项研究试图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。 将对最近到勒纳海槽（Lena Trough）的航行中收集的岩石进行分析和解释，勒纳海槽是北大西洋/北极分离欧洲和北美大陆边缘的年轻裂谷带。矿物分离从橄榄岩地幔岩从这个amagmatic裂谷将进行分析放射性同位素的Os，Re，Nd和Hf测试是否有一个软流圈或大陆岩石圈起源的勒纳海槽基底。 如果岩石有一个次大陆源，同位素应显示非常低的Os同位素比值和分散的Nd和Hf值。 年轻的软流圈起源将反映在均匀年轻的Nd和Hf模型年龄和Os同位素组成，匹配全球平均深海橄榄岩value.Broader影响：该项目通过支持两个机构的新实验室和设备，加强了科学基础设施。它还开发了一种新的技术，通过直接注射，改进了以前的鼓泡方法测量Os同位素。 这项工作将使本科生能够进行研究，并培养一名研究生。 将努力从理科人数不足的群体中招收研究生。

(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.