The Geological Survey of Western Australia (GSWA) calculates the age of rocks by measuring isotopes of uranium, thorium, and lead in minerals such as zircon, baddeleyite, and monazite. We use advanced tools to measure these isotopes, including the sensitive high-resolution ion microprobe (SHRIMP) at Curtin University and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) at Curtin and The University of Western Australia. We also work with experts at Curtin University to use a method called Ar/Ar (argon/argon) geochronology, which helps to date processes like cooling, deformation, and crystallisation in rocks with potassium-rich minerals.
By combining this age data with other isotopic systems, like Lu–Hf (Lutetium–hafnium), Sm–Nd (Samarium–neodymium), Rb-Sr (rubidium–strontium) and oxygen isotopes from a range of different minerals or whole-rock samples, we can better understand how the Earth’s crust formed and changed over time. This work is especially useful in poorly studied areas, as it helps us target new and valuable mineral deposits in Western Australia.
We share this information through GeoVIEW.WA. You can view geochronology and isotope data alongside other important datasets, like geological maps, geophysics, and mineral exploration data. The information is updated regularly.
Geochronology and isotope geology information can also be obtained through:
Data and Software Centre (DASC) — download ESRI Shape files, Google Earth KML files, or MapInfo TAB files.
DEMIRS eBookshop — Geochronology records, use Advanced Search to filter by author, year, sample number, map name, and other terms.
