Northern Territory Geological Survey (NTGS) has an ongoing geochronology and isotope geochemistry program, supporting NTGS regional geoscientific investigations and mapping projects across the Territory.
NTGS, with collaborators, undertake a range of analyses, including:
- Sensitive High Resolution Ion Microprobe (SHRIMP) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS)
- U-Pb zircon and monazite geochronology
- LA-ICPMS in situ garnet rare earth element (REE) analysis and Hf zircon isotopic analysis
- SHRIMP and Secondary Ion Mass Spectrometry (SIMS) O zircon isotopic analysis
- Sm-Nd whole-rock and mineral isotopic analysis using Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS).
Undertaking these types of studies allows NTGS geologists to understand the timing and nature of geological processes important to the geological evolution of the Northern Territory.
- U-Pb zircon and monazite studies are undertaken to constrain the absolute timing of geological events, including magmatism, metamorphism and deformation, and the source regions for detrital zircon
- In situ garnet and zircon REE and Ti analyses are used to link metamorphic zircon growth to pressure-temperature conditions.
- Sm-Nd wholerock and Lu-Hf zircon studies are undertaken on dated samples to provide further information on crust formation. These tools are useful to “see back” through overprinting tectonothermal events to understand the geological process happening at the time of formation.
- δ18O analysis of dated zircons provides information about crust formation and crust recycling events and post-emplacement hydrothermal events. Coupled with zircon Hf data can be used to identify zircon that has grown in mantle-derived melt and the timing of its extraction from the mantle.
SHRIMP U-Pb geochronology under the National Collaborative Framework.
University of Tasmania:CODES (ARC Centre of Excellence in Ore Deposits)
LA-ICPMS U-Pb or Pb-Pb zircon and monazite isotopic analysis and LA-ICPMS in-situ garnet REE analysis
University of Melbourne: School of Earth Sciences, Isotope Geochemistry Group
Lu-Hf MC-LA-ICPMS zircon and Sm-Nd, Rb-Sr and Pb-Pb wholerock/ mineral isotopic analysis
The University of Western Australia: Centre for Microscopy, Characterisation and Analysis
Zircon oxygen isotopic analysis using SIMS.
- Kositcin N, Whelan JA, Hallett L and Beyer EE, 2014. Summary of results. Joint NTGS–GA geochronology project: Amadeus Basin, Arunta Region and Murphy Province, July 2012–June 2013. Northern Territory Geological Survey, Record 2014-005.
- Kositcin N, Beyer EE and Whelan JA, 2014. Summary of results. Joint NTGS–GA geochronology project: Arunta Region July 2013–June 2014. Northern Territory Geological Survey, Record 2014-008.
- Kositcin N, Normington VJ and Edgoose CJ, 2015. Summary of results. Joint NTGS–GA geochronology project: Amadeus Basin July 2013–June 2014. Northern Territory Geological Survey, Record 2015-001.
Products released from the Geochronology project prior to 2014 can be found in the Product Catalogue