Orientation study of northern Arkansas. National Uranium Resource Evaluation program. Hydrogeochemical and stream-sediment reconnaissance

Samples of ground water, stream water, and sediment were collected at 335 sites for an orientation study of northern Arkansas. Each stream site consisted of both sediment and stream water (if available), and each sediment sample was sieved to produce four size fractions for analysis. The orientation area included all or parts of Benton, Carroll, Madison, and Washington Counties. Several black shales, including the Chattanooga Shale, crop out in this area, and the Sylamore Sandstone Member has local radiation anomalies. The following analyses were performed for all water samples (both ground water and stream water): pH, conductivity, total alkalinity, temperature, nitrate, ammonia, phosphate and sulfate. Additional water was collected, filtered, and reacted with a resin that was then analyzed by neutron activation analysis for U, Br, Cl, F, Mn, Na, Al, and Dy. In addition, ground water samples were analyzed for He. The stream sediments were analyzed by neutron activation for U, Th, Hf, Ce, Fe, Mn, Sc, Ti, V, Al, Dy, Eu, La, Sm, Yb, and Lu