Sr Isotopes in Seawater - Stratigraphy, Paleo-Tectonics, Paleoclimate, and Paleoceanography

Studies of Sr isotopic composition of thousands of samples of marine sediments and fossils have yielded a curve of 87Sr/86Sr versus age for seawater Sr that extends back to 1 billion years. Because the ratio is always uniform in the oceans globally at any one time, it is useful as a stratigraphic correlation and age-dating tool.