Ion Beam Analysis of Zircon with Applications to Earth Science

Diffusion is vital for interpreting geochronometric data, however, there are still gaps in our knowledge about this process for key minerals such as zircon. Zircon crystals are some of the oldest mineral grains on Earth and have strong chemical retention properties. Thus, zircons act as a window into the environment of the early Earth. Using nuclear analysis techniques on zircon crystals to measure the diffusion properties of tracer elements and those relevant to radioactive decay can improve estimations of mineral ages and provenance, thus aiding in a greater understanding of Earth and the early Solar System. Rutherford backscattering analysis (RBS) can be used to measure the diffusion of helpful geochemical indicators such as lead, tantalum, phosphorus, and xenon in synthesized zircon (ZrSiO4). RBS analysis supplies crucial data from which concentration profiles can be extracted. These profiles yield element concentration at various crystal depths on the nanometer scale. From these concentration profiles, a diffusion constant and closure temperature of an isotopic environment can be determined. The Ion Beam Lab at the University at Albany has been used to perform RBS analysis. Preliminary data has been collected for the diffusion of tantalum in zircon and will be presented.