Very intense gamma-ray emissions produced by nuclides in the 238U-decay series were measured in active and relict spring deposits along the Dead Sea coast. Precipitates of Ra near sites of modern springs provide a local source of Rn to coexisting waters. Relict spring deposits, representing prior Dead Sea levels, contain high concentrations of Ra. The Ra in both cases has been derived from the Dead Sea waters (or from the Dead Sea in combination with a Ra component from the primary spring water) and coprecipitated with hydrous oxides of Mn and Fe. The metal oxides precipitated in response to the mixing of the fresher spring waters with the Dead Sea brine.