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.
