ABSTRACT
Valley filling sandstone of the Red Fork and lower Skinner sequences in parts of Noble, Pawnee, and Osage Counties, Oklahoma, exhibits linear distribution patterns that differ from regional sediment dispersal systems and result in the stacking of reservoirs. Middle Pennsylvanian (Desmoinesian) Cherokee Group sandstones are dominantly channel filling and have produced large volumes of oil and gas since their discovery in the early twentieth century. The sandstone-bearing channels at the focus of this study are highly elongated and narrow (≥10 mi long and ≤1 mi wide [≥16 km long and ≤1.6 km wide]), contain thick accumulations of sandstone (50–200 ft [15–60 m] thick), and are unexpectedly stacked. These observations prompted the hypothesis that accommodation was generated along the same trend across two fourth-order high-frequency cycles for a cumulative time span ranging from 0.4 to 1.0 m.y. The distribution of these narrow, channel-filling, “shoestring” sandstones can be difficult to map using wire-line log control. Furthermore, if the orientation of these channels was influenced by faulting, these faults are not recognized in structure and thickness maps constructed from wire-line log data. A three-dimensional seismic volume covering part of the study area provided data necessary to delineate faults that influenced paleotopography and drainage patterns during Cherokee deposition. It is proposed that erosion favored the fault-influenced topographic lows, generating valleys that subsequently filled during transgression. By detecting the causative fault at the contact between the Mississippian carbonate section and overlying Pennsylvanian siliciclastics, seismic data provide an additional exploration tool to locate lucrative but elusive Pennsylvanian shoestring sandstone reservoirs.