Radon in the helium-bearing natural gas of the Texas panhandle

The known quantity of helium in the Texas Panhandle gas reservoir
is greater than could be explained by assuming normal geologic conditions. Radon content of the gas varies between about 10 and 250 micromicrocuries
per liter (S. T. P.), and the more highly radioactive wells
are clustered in several groups. Mathematical analysis indicates that
the larger concentrations of radon could not be derived from rocks of
normal radioactivity.