Radiogenic isotope geochronology is used to determine the absolute timing of geological events, and is an essential component of geoscience programs at the Geological Survey of Western Australia (GSWA).
Access Geochronology (GeoVIEW.WA)
The sensitive high-resolution ion microprobes (SHRIMPs) at Curtin University’s John de Laeter Centre are used extensively by GSWA to date rock samples by measuring uranium, thorium and lead isotopes in zircon, baddeleyite, monazite and other minerals. GSWA also collaborates with Ar–Ar geochronology specialists at the John de Laeter Centre to determine the ages of cooling, deformation and crystallisation of rocks containing potassium-bearing minerals.
Understanding crustal evolution, including the formation of mineral deposits, is enhanced greatly by combining geochronological information with radiogenic isotope data, such as Lu–Hf and oxygen analyses of zircon crystals and Sm–Nd analyses of whole-rock samples. Using these techniques to elucidate both the temporal and spatial evolution of crust and mantle, particularly in underexplored areas, is an important tool for identifying new mineral provinces and improving exploration strategies in Western Australia.
Geochronology and isotope geology information can be accessed using GeoVIEW.WA. This online interactive mapping system allows data to be viewed and searched together with other datasets, including Geoscience Australia geochronology data, geological maps and mineral exploration datasets.
The information provided in GeoVIEW.WA is updated regularly.
GSWA geochronology and isotope geology information can also be obtained through the following links:
- Compilation of geochronology information 2016 — the latest is complete to June 2016
- Geochronology Records where you can search by author, rock type, map name, and other attributes
- a downloadable ESRI Shape file, Google Earth KML file or MapInfo TAB file, from the Data and Software Centre.
U–Pb measurements are conducted using the SHRIMP II instruments at the John de Laeter Centre of Mass Spectrometry. Lu-Hf isotope measurements are conducted by the Australian Research Council’s (ARC) National Key Centre for Geochemical Evolution and Metallogeny of Continents (GEMOC) via the ARC Centre of Excellence for Core to Crust Fluid Systems (CCFS) at Macquarie University in Sydney.
For more information contact: