Radon and radium are specific indicators of uranium. Radon in particular is easily analyzed in the field or in a portable lab. For this reason and because of its mobility as a soluble noble gas, radon has received considerable attention in exploration. The mobility of radon is complicated by its short half-life (3.8 days) and by movements of earlier members of the decay series.

Claims of the successful application of radon geochemistry to detect uranium deposits beneath several tens of meters of cover (including shale and coal beds) seem extravagant but may warrant further study. In areas of shallow overburden, radon in soil gas can extend evaluation to depths beyond reach of the scintillometer. Radon to thoron ratios are useful in this work as well as radon content itself. Day-to-day variations of radon content in soil gas are confusing, but seldom obscure trends and anomalies.

Lake-water radon anomalies are associated with two recent major uranium discoveries in the Canadian Shield. In both discoveries, the radon anomalies were detected in the earliest stages of exploration in the area.

Radium, the parent of radon, also can be readily determined in a portable laboratory. In an example from southeast Texas, a dramatic reduction in radium values has been measured in groundwater within a few hundred feet of an orebody. Anomalous radium measurements other than those associated with uranium mineralization or geothermal waters are extremely rare.

End_of_Article - Last_Page 754------------