GSA Today
Volume 21, Number 2 (February 2011)

About the cover:
Elevation and relief map of New Mexico, USA, showing the Rio Grande, which flows southward along the axis of the slowly extending Rio Grande rift. Regional heat flow data and foreshortened seismic velocity profiles suggest that upward mantle advection is focused along the western boundary of thick lithosphere under the Great Plains province near the eastern margin of the Rio Grande rift. Digital cartography by Lewis Gillard, New Mexico Bureau of Geology and Mineral Resources, New Mexico Tech. See "Alternative perspectives of crustal and upper mantle phenomena along the Rio Grande rift," by M. Reiter and R.M. Chamberlin, p. 4–9.

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