Dynamic and geochemical evolution of the lithospheric mantle beneath the Western Ross Sea Area, Antarctica

Columbia University, New York NY

Investigators

Abstract

Intellectual Merit: The subcontinental lithospheric mantle preserves the geochemical imprint left by its tectonic history, including continental crust extraction, replacement by ?juvenile? asthenosphere during orogeny or rifting, metasomatic re-enrichment by subduction- related melts and fluids or mantle plume activity. Modern analytical techniques make it possible to unravel this geochemical evolution through whole rock, mineral, or in-situ trace element and Sr-Nd-Hf-Os-He isotope analyses. The western Ross Sea area is particularly suited for such a study, as it is characterized by a multi-stage tectonic history. Today the Western Ross Sea area is part of the West Antarctic Rift System (WARS), which represents one of Earth?s largest rift systems. The PIs propose to constrain the dynamic and geochemical evolution of the subcontinental lithospheric mantle using modern analytical techniques using samples from multiple locations between the Mt. Erebus Province and Victoria Land available through collaborations with investigators from previous expeditions and the US Polar Rock Repository. The available mantle xenoliths are fresh and range from spinel lherzolites to metasomatized wehrlites and rare websterites, and many carry hydrous phases. Broader impacts: The proposed work will have broad scientific impacts and will initiate national and international collaborations. The project will form the basis of a Ph.D. thesis for a graduate student and a postdoc will collaborate on the study. Results of the study will be presented at international meetings and published in international peer-reviewed journals and will be highlighted at the LDEO annual Open House.