Processing and Interpretation of Seismic Reflection Data Near the Bane Dome in Bland County, Virginia.

摘要

The purpose of the study was to process and interpret a seismic reflection line from Bland County, Virginia, and to compare it to an earlier line in this location. A longer Vibroseis sweep with greater bandwidth was used for the new line, which provided a considerable improvement in signal to noise ratio and resulted in better residual statics. Additional processing steps, including crooked line CDP sort and predictive deconvolution, also led to improved resolution, particularly in the shallow section. The geologic section interpreted from the seismic profile represents a series of fault slices between the St. Clair Narrows thrust plates above autochthonous Lower Cambrian shelf strata. A previously interpreted Eocambrian rift basin is clearly defined on this line; the basin is bounded by a large normal fault at its north end. Seismicity in Bland and Giles counties may originate in reactivated Eocambrian faults which presumably formed during opening of the Proto-Atlantic Ocean.