INFLUENCE OF MISSISSIPPIAN PALEOTOPOGRAPHY AND PALEOSTRUCTURE ON DISTRIBUTION OF THE PENNSYLVANIAN LOWER SKINNER AND RED FORK SANDSTONES IN PARTS OF NOBLE, PAWNEE AND OSAGE COUNTIES

Deposition on the Cherokee Platform during the Pennsylvanian was complex due to high frequency depositional cyclicity and structural overprint. On the Cherokee Platform, the Lower Skinner and Red Fork intervals of the Cherokee Group, Desmoinesian Series, are dominated by low energy channel-filling sandstones of fluvial-estuarine origin. This study examines the hypothesis that pre-Pennsylvanian paleotopography and paleostructure influenced distribution and the depth of incision of valleys in the Lower Skinner and Red Fork sandstone intervals, which contain these sandstones and have produced large volumes of oil and gas since their discovery in the early 20th century. However, some of these channels are highly elongate and narrow, making it difficult to map their distribution using wireline logs. If the orientation of these channels was influenced by deeper structure, in particular faulting in the Mississppian interval, seismic could provide an additional exploration tool to locate these lucrative, but elusive reservoirs. The Upper Morrow sandstone in western Kansas provides an analogue for the study as the distribution patterns for sandstone in the Morrowan interval appears to be strongly influenced by the Mississippian paleotopography (Mannhard and Busch, 1974). In addition to using an integrated seismic and wireline log dataset to characterize fault locations, Mississippian paleotopography and sandstone distribution, seismic mapping is used to examine interval thicknesses and make inferences concerning depocenter configuration and accommodation during Desmoinesian deposition.