We used multicomponent seismic reflection/refraction data to determine seismic velocities, Poisson's ratios and geometries of shallow subsurface structures across the Cheyenne Belt, an Archean-Proterozoic boundary in southeastern Wyoming. The travel-times of P-wave first arrivals were inverted to obtain a model of both P-wave velocity and subsurface geometry. Since S-wave data quality was inferior to that of the P-wave data and S-wave ray coverage of the subsurface was discontinuous, we proposed a method to estimate Poisson's ratio using SiO2 concentration and the average atomic weight (AAW) of a formation with known mineral and oxide compositions. Subsequently, the final P-wave velocity model was converted into an initial S-wave model using Poisson's ratios estimated by this method. The S-wave data were inverted for velocities only, keeping the subsurface geometry derived from P-wave inversion constant. The inversion of P- and S-wave travel times resulted in a shallow subsurface model of rock properties, which was interpreted based on surface geology and Poisson's ratio variations to provide a near-surface geological structure model.
|Original language||English (US)|
|State||Published - Jan 1 2003|
|Event||2003 Society of Exploration Geophysicists Annual Meeting, SEG 2003 - Dallas, United States|
Duration: Oct 26 2003 → Oct 31 2003
|Other||2003 Society of Exploration Geophysicists Annual Meeting, SEG 2003|
|Period||10/26/03 → 10/31/03|
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