Spring Colloquium 2017

March 30, 2017 -
4:00pm to 5:00pm

Dr. Lara Wagner

Staff Scientist 

Department of Terrestrial Magnetism 

Carnegie Institution of Washington

Thaw 11

Not so stable after all: Lithospheric structures beneath the southeastern Appalachians and implications for modern tectonism

The southeastern United States has long been considered to be part of the "stable" North American continent, separated from the nearest plate boundary by almost 3000 km and 180 Million years. However, recent work has highlighted ongoing "tectonic" activity including distinctive patterns of seismicity, uplift of the Appalachian escarpment and the Cape Fear Arch, and Eocene age volcanism. New seismic data from the EarthScope Transportable Array, combined with data collected from a number of more regional, high density deployments, shed light on the highly variable nature of the mantle lithosphere and crust across the southeastern United States. These results suggest that modern tectonism in this area is controlled both by inherited structure and by ongoing evolution of "stable" continental lithosphere, even far removed from plate boundary settings.