Seismic Evidence of Faulting at Three Different Geologic Scales in the Arbuckle‐Simpson Aquifer, Oklahoma

Seismic reflections from boundaries within the Ordovician Arbuckle-Simpson aquifer correlate with boundaries seen in well logs and cores. Seismic surveys at different geologic scales within this karst aquifer display the same fault character regardless of the survey’s target depth. Faults observed at intermediate depths in the Arbuckle-Simpson aquifer extend upward to the location of mapped fault traces, and such faults are seen clearly on ground penetrating radar and electrical resistivity imaging surveys. Some of these faults also extend downward cutting the basement, and, in one instance, form a graben at the aquifer/basement boundary. This suggests that mapped fault locations, confirmed by near-surface geophysics, may be a fingerprint of steeply dipping faults extending through the carbonate section into the basement.