Seismic Study of Continental Orogenic Zones: The Rocky Mountains and the Midcontinental Rift

PIs: Stephen Gao and Kelly Liu
07/2001 - 06/2004 by National Science Foundation; EAR#: 0107055

The formation and evolution of continental orogenic zones is one of the most fundamental yet poorly understood problems in geoscience. Among the various types of continental orogenic zones, the two that are most pervasive are those in the vicinity of a plate boundary such as the western North American orogenic zone, and those associated with continental rifting such as the 1.1 billion-year old Midcontinent rift (MCR) in the central United States. The proposed study is aimed at improving our understanding about the formation and evolution of continental orogenic zones by using a unique broadband seismic data set that we recently recorded along an E-W profile across Kansas. We propose to locate and characterize the mantle transition between the Rocky Mountains and the Great Plains, and to explore the deep structure and possible fossil anisotropy beneath the MCR by apply various of seismological techniques to the broadband data set. We will also perform geodynamic modeling aiming at looking for a model that best explains the uplift history of the Rocky Mountains since the Laramide orogeny by using the seismic results as constraints.