The Geoscience Australia Geochronology Laboratory provides high quality age information to support research objectives in both internal and collaborative regional and specific interest projects. Collaborative projects are operated with the State and Northern Territory Geological Surveys, universities and the CSIRO.
Geoscience Australia installed a Sensitive High Resolution Ion MicroProbe (SHRIMP) in late 2007 with commissioning and testing through the first quarter of 2008. This facility provides in-house analysis of mineral phases such as zircon and monazite and enables scientists to have detailed management of the 'outcrop-to-publication' analytical cycle, which will ensure that the highest quality data are provided to research projects. The in-house facility also will aid the development of new analytical methods, expanding Geoscience Australia's capability to address increasingly complex geoscience issues.
The Minister for Resources, Energy and Tourism, the Hon. Martin Ferguson AM MP, launched the SHRIMP at Geoscience Australia on 1 April 2008.
The laboratory also has a strong network of relationships with geochronology laboratories around the world which enables additional access to a range of analytical methods such as argon-argon dating (40Ar/39Ar) and thermal ionisation mass spectrometry uranium-lead dating (TIMS U-Pb).
Many of Australia's world class mineral deposits formed between 2700 to 2500 million years ago (Archean age) and 1700 to 1500 million years ago (Paleoproterozoic to early Mesoproterozoic age). These include the Archean gold deposits near Kalgoorlie in Western Australia, and the Paleoproterozoic to Mesoproterozoic zinc-lead-silver (Zn-Pb-Ag), copper (Cu) and copper-gold (Cu-Au) deposits in the Mount Isa-Cloncurry region, and at Broken Hill and Olympic Dam. Because shelly fossils are absent in rocks older than approximately 500 million years, it is not possible to use paleontology to determine the ages of rocks which host most of Australia's mineral wealth.
Datasets collected in the laboratory are used to constrain:
- the depositional ages of the sedimentary rocks which host Australia's mineral deposits
- the intrusion or extrusion ages of igneous rocks found in these areas
- the timing of metamorphic events which alter these rocks
- the timing of fluid migration events which led to the formation of economic deposits.
The laboratory aims to provide improved efficiencies in mineral exploration through a better understanding of the ages of the rocks which host Australia's mineral wealth and the fluid flow events which led to their formation.
Current and concluded projects
The laboratory provides high quality age information to support research objectives in both internal and collaborative regional and specific interest projects. Collaborative projects are undertaken with the State and Northern Territory Geological Surveys, universities and the CSIRO.
The laboratory is working in the following Geoscience Australia projects associated with the Onshore Energy Security Program:
- Uranium Systems Project
- Regional Geodynamics Project (incorporating Mt Isa-Georgetown, Gawler-Curnamona, Northern Territory, and Northern Western Australia projects)
The laboratory also provides support to State and Northern Territory mapping projects under the auspices of the National Geoscience Agreement.
Projects which geochronologists have worked on include:
- North Australia Project (NAP) Mineral Promotion
- Gawler Mineral Promotion
- TASMAP: Understanding Major Geological Elements and Mineral Potential
- Edmund and Collier Basins field mapping and Gascoyne Complex field mapping project with the Geological Survey of Western Australia