Utilizing the geochemical data from the National Uranium Resource Evaluation (NURE) Program: a case study of the Billings quadrangle, Montana/Wyoming

Some 1665 water samples and 1426 sediment samples were collected from 1999 locations in the Billings quadrangle, Montana/Wyoming, in the summer and fall of 1978 by a private contractor for the Los Alamos Scientific Laboratory (LASL). The LASL analyzed the water samples for uranium plus 12 additional elements and the sediment samples for uranium plus 42 additional elements. The data were then released to the Montana College of Mineral Science and Technology (MCMS and T), who was responsible for the evaluation of the data to determine if there were areas appearing favorable for further investigations by the private sector. The data have subsequently been released by the LASL in an open-file report (Broxton, 1979). Statistical evaluations of the data were undertaken for uranium, copper, nickel, and chromium. Lognormal probability curves showing cumulative frequency percent versus concentration and histograms were plotted for both the water and sediment data for all four elements. The probability curves and histograms indicated different data populations between the Beartooth Mountains and the rest of the quadrangle; thus the two areas were treated separately during evaluation of the data. Several areas, one along the Clarks Fork of the Yellowstone River from the town of Bridger to Laurel, another just south of Billings, and another on the northeastern side of the Pryor Mountains, are suggested as favorable for further investigations for uranium. Two areas, one south of Big Timber in the Deer Creek drainage and another along Work Creek, had a number of grouped contours, sample clusters, and individual samples with high concentrations of copper, nickel, and chromium and may deserve further study. Several tributaries of Rosebud Creek, especially Fiddler Creek, had anomalous concentrations of chromium