The Determination of Radon Activities in Ground Water from Wisconsin Tills in Southwestern Ohio and Southeastern Indiana

Abstract

Two hypotheses have been suggested by previous workers to explain the relatively elevated radon activities of ground water in certain areas of southwestern Ohio and southeastern Indiana. First, radon may be produced close to or at the Ordovician-Silurian unconformity by the concentration of uranium and radium on iron and manganese oxides and hydroxides and on clay minerals at this zone of weathering. Second, radon may be formed from the radioactive decay of radium which is concentrated on iron-oxides in zones of higher hydraulic conductivity in the lower carbonate section of the Silurian System. In both cases, it has been proposed that the elevated radon activities result from either the application of radium-bearing phosphate fertilizers or from the inclusion of radium-bearing fragments of Devonian black shale in the till.