Research
SESAME
SouthEastern Suture
Of the Appalachian Margin Experiment
The broad goal of the SESAME proposal is to improve understanding of lithospheric accretion processes and models of passive margin development. The Paleozoic Appalachian orogen in the southeastern United States - specifically the suture between Laurentia (proto-North America) and Gondwana (proto-Africa/South America) in southern Georgia provides an ideal location for imaging crust and mantle structures related to accretion.
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PULSE
PerU Lithosphere and Slab Experiment
The goal of the PULSE project is to investigate the causes and consequences of Peruvian flat slab subduction using broadband seismic data analyses. Flat slab subduction refers to the near-horizontal subduction of an oceanic plate at some depth below the overriding lithosphere.
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CAUGHT
Central Andean Uplift
and the Geodynamics of High Topography
CAUGHT is a multidisciplinary effort to test these end-member geodynamic models for the surface uplift, deformation history, and lithospheric evolution of the central Andes of southern Bolivia and Peru.
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Appalachian Seismic Transect
What is the lithospheric structure of the southern Blue Ridge Mountains in North Carolina/Tennessee? How was continental accretion accommodated in the mantle in the southern Appalachians? Can we identify active seismic zones that could pose hazards to the local population? Very little is known about the lithospheric structure of the southern Appalachian Mountains at depth.
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High Lava Plains
I'm interested in understanding the unusual age-progressive silicic volcanism associated with the High Lava Plains (HLP) of south-eastern Oregon. This volcanic sequence began ~15 Ma near the Owyhee Plateau in the south-easternmost corner of the state and then progressed to the WNW ending up today at the active Newberry caldera along the eastern margin of the Cascade arc.
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Seismic Tomography
One of my more theoretical interests relates to how we create 3-D images of the earth's interior. Since we cannot drill more than a few kilometers into the earth, and we don't have rock samples from much below 100 km below the surface, we must rely on information gleaned from seismic waves to learn more about the earth's interior.
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Central Chile/Argentina Flat-Slab
In central Chile and Argentina, near Santiago, Chile, and San Juan, Argentina, the downgoing Nazca plate does not descend normally, but rather descends to a depth of ~100 km and then bends upwards to travel horizontally for several hundred kilometers before resuming its descent into the mantle. The horizontal portion of the plate closely parallels the projected location of the subducting aseismic Juan Fernandez Ridge, whose overthickened, buoyant oceanic crust may be in part responsible for the slabs unusual 3-D geometry.
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