Linear-traverse surveys of helium and radon in soil gas as a guide for uranium exploration, central Weld County, Colorado

Linear-traverse surveys of helium and radon in soil gas were performed and evaluated as a guide for uranium exploration in central Weld County, Colo. Repeated sampling over a 5-month period eventually delineated a helium anomaly along the main 11.2 km traverse, and that anomaly may be related to a uranium occurrence. A single traverse is difficult to interpret. A grid sampling pattern, no more time consuming than a repeated linear traverse, is preferred. Radon anomalies along the traverses are from radon-220, the thorium decay series member, and do not show a positive correlation with the helium analyses.