Integrated Evaluation of Mantle Xenoliths from the Fosdick Mountains, Antarctica

These recently entrained mantle xenoliths offer a unique opportunity to characterize the West Antarctic lithospheric mantle that has been subject to active modification from Cretaceous to Present by plate-boundary processes, such as orthogonal to oblique plate convergence, intracontinental rifting, continental breakup, and Neogene volcanism.

These volcanic centers derive from heterogeneous mantle sources and host a compositionally diverse suite of mantle xenoliths that have varied mineral assemblages and microstructures. The proposed research has two complementary goals: to assess structural and compositional heterogeneity within the upper mantle and the variability of intrinsic and extrinsic variables at a variety of lithospheric levels; and to use textural and compositional characterization of the xenolith suite to elucidate possible causes of heterogeneous seismic anisotropy within the Marie Byrd Land mantle lithosphere and inform competing hypotheses explaining the active volcanism, thermal anomaly, and slow seismic velocities beneath West Antarctica.