Abstract

The 87Sr/86Sr ratio has been extensively used in groundwater studies for several reasons. While classified geochemically as a trace element, Sr is found in easily measurable quantities in a wide variety of rocks. It is soluble in aqueous solution as the +2 ion and is geochemically very similar to Ca, the latter a major alkaline-earth constituent of rocks. The half-life of 87Rb, which decays to 87Sr, is such that considerable variations exist in …