This effort focuses on an area of known inter-basin transfer of ground water. In this area, water from the agricultural, north-draining, Crooked Creek watershed flows southward in the subsurface and issues into the Buffalo River watershed at springs where it is enriched in nutrients and sediments. Information gained during the new geologic mapping will be coupled with results from dye-trace studies to permit the National Park Service personnel to better manage current and future pollutants that may impact the water quality of the Buffalo River, and to better understand the hydrologic processes active within the watershed's vast karst landscapes. The geologic information will also add insight into the formation of Fitton Cave, the longest in Arkansas, which is protected in the park's enabling legislation.
Several findings are already evident from the new mapping.
Boone Formation in this area may be particularly susceptible to dissolution because it has a lower content of insoluble chert than is typical elsewhere in northern Arkansas. Springs in the Buffalo River watershed are concentrated at the unconformable contact between the basal Mississippian St. Joe Member of the Boone Formation and underlying Ordovician Everton Formation rocks. These features suggest that the Boone Formation is the principal karstic aquifer that controls ground-water flow into the watershed. Several newly recognized faults and related folds offset the rock units. The two largest springs, characterized in a previous study as having elevated nutrient concentrations, lie near a projected intersection of two faults, suggesting that these structures have an important influence on ground-water flow.