Evaluating Models for Lithospheric Loss and Intraplate Volcanism Beneath the Central Appalachian Mountains

The eastern margin of North America has been shaped by a series tectonic events including the Paleozoic Appalachian Orogeny and breakup Pangea during Mesozoic. For past ∼200 Ma, passive continental margin; however, there is evidence in Central Mountains for post-rifting modification lithospheric structure. This includes two co-located pulses magmatism that post-date rifting event (at 152 47 Ma) along with low seismic velocities, high attenuation, electrical conductivity upper mantle. Here, we synthesize evaluate constraints on evolution Mountains. These include tomographic imaging Mid-Atlantic Geophysical Integrative Collaboration array, gravity heat flow measurements, geochemical petrological examination Jurassic Eocene magmatic rocks, estimates erosion rates from geomorphological data. We discuss set possible mechanisms loss intraplate volcanism beneath region. Taken together, recent observations provide compelling Appalachians; while they cannot uniquely identify processes associated this loss, narrow range plausible models, important implications our understanding lithosphere. Our preferred models invoke combination (perhaps episodic) via Rayleigh-Taylor instabilities subsequent small-scale mantle shear-driven upwelling maintains region thin lithosphere causes partial melting asthenosphere.