Uranium hydrogeochemical and stream sediment reconnaissance of the Cheyenne NTMS Quadrangle, Wyoming

Between June 1976 and October 1977, 1138 water and 600 sediment samples were systematically collected from 1498 locations in the Cheyenne NTMS quadrangle of southeast Wyoming. The samples were analyzed for total uranium at the Los Alamos Scientific Laboratory. The uranium concentration in waters ranged from 0.01 to 296.30 parts per billion (ppB), with a median of 3.19 ppB and a mean of 8.34 ppB. The uranium in sediments ranged from 0.8 to 83.0 parts per million (ppM) with a median of 3.4 ppM and a mean of 4.5 ppM. Arbitrary anomaly thresholds were selected to isolate those water and sediment samples containing uranium concentrations above those of 98% of the population sampled. Using this procedure, 23 water samples above 54.50 ppB and 12 sediment samples above 14.0 ppM were considered anomalous. Several areas appear favorable for further investigation for possible uranium mineralization. High uranium concentrations were detected in waters from the northeast corner of the Cheyenne quadrangle. High uranium concentrations were detected in sediments from locations in the southern and central Laramie Mountains and along the southeast and east-central edges of the study area.