Analysis of the Sr isotope composition

The 87Sr/86Sr ratio allows us to obtain information about the origin and processes that affected all kind of materials. This type of study is based on the fact that the amount of 87Sr has been increasing since the origin of the Earth due to the contributions from the decay of 87Rb and the geochemical behavior of Rb and Sr. Materials with an origin in Earth"s mantle present low Rb/Sr and hence low 87Sr/86Sr. On the contrary, materials from the upper crust have higher Rb/Sr and hence higher 87Sr/86Sr. Unexpected values ​​can be explained in different ways, such as assimilation and/or crustal contamination.

Sr isotopic analysis can be performed for studies in geochronology, petrology, marine-carbonate dating, diagenesis, hydrogeology, and archaeology.