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Characteristics Of Mantle Fabrics Beneath The South-Central United States: Constraints From Shear-Wave Splitting Measurements, Stephen S. Gao, Kelly H. Liu, Robert J. Stern, G. R. Keller, John Patrick Hogan, J. Pulliam, E. Y. Anthony

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

New shear-wave splitting measurements at permanent broadband seismic stations in the south-central United States reveal the orientation and degree of polarization of mantle fabrics, and provide constraints on models for the formation of these fabrics. For stations on the stable North American craton, correspondence between observed polarization direction of the fast wave and the trend of Proterozoic and Paleozoic structures associated with rifts and orogenic belts implies a lithospheric origin for the observed anisotropy. The largest splitting times (up to 1.6 s) are observed at stations located in the ocean-continent transition zone, in which the fast directions are parallel to …