Seismic evidence for an ancient rift beneath the Cumberland Plateau, Tennessee: A detailed analysis of broadband teleseismic P waveforms

摘要: Broadband receiver functions developed from teleseismic P waveforms recorded on the midperiod passband of Regional Seismic Test Network station RSCP are inverted for vertical velocity structure beneath Cumberland Plateau, Tennessee. The detailed broadband obtained by stacking source-equalizd horizontal components waveforms. resulting most sensitive to shear near station. A time domain inversion routine utilizes radial function determine this assuming a crustal model parameterized many thin, flat-lying, homogeneous layers. Lateral changes in identified examining azimuthal variations structure. results reveal significant rapid lateral midcrustal that interpreted relation origin East Continent Gravity High located northeast RSCP. events arriving show high-velocity layer not present southeast azimuth. This can be shown support idea feature is part Keweenawan rift system. Another interesting derived models indication crust-mantle boundary Plateau thick, probably laminated transition zonemore » between depths 40 and 55 km, result consistent with interpretations early refraction work area.« less