Title:
Imaging Mantle Temperature beneath western North America

Abstract:
Western North America sits at an elevation ~2 km higher than the
Great Plains to the east. The region is characterised by a very thin
tectonic plate, anomalies in the gravity field and in seismic velocities,
as well as abundant volcanism in the last ~30 million years (including
Yellowstone volcano). The chemical compositions of the most recent volcanic
rocks correlate with seismic velocities in the upper mantle. I use forward
and inverse modelling of volcanic compositions to determine depth and
degree of melting, and thus mantle temperature. Independently, I also
derive temperature from seismic velocities. Mantle temperatures calculated
with both methods agree closely and support a model of mantle upwelling
beneath a thin plate to generate both uplift and volcanism in the area.