Extending our understanding of the age of the state's rocks and the timing of mineral systems
Radiogenic and stable isotope geochronology and geochemistry are used to determine the age and origins of minerals. The data provides valuable information about rock relationships and the timing of geological events. The GSSA has been using radiogenic isotopes since the 1960s, and is at the forefront in the use of isotope age determination techniques and isotope geochemistry to enhance the understanding of South Australia’s geological history.
Currently, Isotope Geochronology and Geochemistry is undertaken by staff of the Radiogenic Isotope Group within the GSSA on samples collected as part of GSSA mapping programs and also from the state’s extensive collection of drill core reference material housed in the Core Library. In addition, the Radiogenic Isotope Group also undertakes collaborative geochronology projects with mineral exploration companies across South Australia under the PACE geochronology program.
Zircons from sample 1924226 from the Jacinth Mine, Eucla Basin.
In addition to SHRIMP facilities, GSSA also routinely makes use of laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS), via instrumentation housed at Adelaide Microscopy, The University of Adelaide. Details of the LA-ICPMS instrumentation.
We also have access via collaborations with various institutions to a range of other geochronology techniques, including 40Ar/39Ar thermochronology, Re-Os geochronology, Sm-Nd geochronology.
Radiogenic and stable isotope geochemistry
Sm-Nd whole rock isotopic data is also collected routinely as part of the GSSA’s regional mapping projects. This is acquired via a collaborative agreement with the University of Adelaide, which includes co-funding of a new Thermal Ionisation Mass Spectrometer. Recently the GSSA has begun to collect Lu-Hf isotopic data from zircon grains via laser ablation-multicollector-inductively coupled plasma mass spectrometry (LA-MC-ICPMS) as part of a collaborative program with researchers from the University of Adelaide. Radiogenic and stable isotope data for elements such as O, Pb and S are collected as required to support specialist studies.
Jagodzinski, E.A.; Reid, A.J. PACE Geochronology: Results of collaborative geochronology projects, 2013–2015. Report Book 2015/00003
Jagodzinski, E.A.; Reid, A.J. U-Pb geochronological data from drill holes Nundroo 3 DDH and Nundroo 2 DDH, Fowler Domain, western Gawler Craton. Report Book 2016/00010
Jagodzinski, E.A.; Reid, A.J.; Dutch, R.A. 2013, Zircon and monazite geochronology via SHRIMP and LA-ICPMS for the northern Gawler Craton, from 2009 GOMA Drilling. Report Book 2013/00013
Dutch, R.A.; Payne, J.L.; Woodhouse, A.J.; Mason, D.R. 2013, Sm-Nd and Hf isotopic data of the Tieyon (5645) 1:100 000 mapsheet. Report Book 2013/00010
Jagodzinski, E.A.; Dutch, R.A. 2013, SHRIMP U-Pb geochronology of the Tieyon (5645) 1:100 000 mapsheet. Report Book 2012/00006
Reid, A. J. & Jagodzinski, E. A. 2012, PACE Geochronology: Results of collaborative geochronology projects 2011-12. Report Book 2012/00012
Reid, A. J. & Jagodzinski, E. 2011, PACE Geochronology: results from collaborative geochronology projects 2009-2010. Report Book 2011/00003
Reid, A.J., Jagodzinski, E.A., Wade, C.E., Payne, J.L., Jourdan, F., 2017. Recognition of c. 1780 Ma magmatism and metamorphism in the buried northeastern Gawler Craton: correlations with events of the Aileron Province. Precambrian Research.
Reid, A.J., Payne, J.L., 2017. Magmatic zircon Lu-Hf isotopic record of juvenile addition and crustal reworking in the Gawler Craton, Australia. Lithos.
A. J. Reid, F. Jourdan & E. A. Jagodzinski. 2017, Mesoproterozoic fluid events affecting Archean crust in the northern Olympic Cu–Au Province, Gawler Craton: insights from 40Ar/39Ar thermochronology. Australian Journal of Earth Sciences: An International Geoscience Journal of the Geological Society of Australia, 64:1, pp 103-119.
K. Lane, E. A. Jagodzinski, R. Dutch, A. J. Reid & M. 2014, Age constraints on the timing of iron ore mineralisation in the southeastern Gawler Craton Australian Journal of Earth Sciences: An International Geoscience Journal of the Geological Society of Australia, 62:1, pp 55-75
Reid, A. J., Keeling, J., Boyd, D., Belousova, E. A. & Hou, B. 2013a. Source of zircon in world-class heavy mineral placer deposits of the Cenozoic Eucla Basin, southern Australia from LA-ICPMS U–Pb geochronology. Sedimentary Geology 286–287, pp 1-19.
Reid, A. J., Smith, R. N., Baker, T., Jagodzinski, E. A., Selby, D., Gregory, C. J. & Skirrow, R. G. 2013b. Re-Os dating of molybdenite within hematite-breccias from the Vulcan Cu-Au prospect, Olympic Cu-Au Province, South Australia. Economic Geology 108, pp 883-894.
Reid, A. J., Jagodzinski, E. A., Armit, R. J., Dutch, R. A., Kirkland, C. L., Betts, P. G. & Schaefer, B. F. 2014a. U-Pb and Hf isotopic evidence for Neoarchean and Paleoproterozoic basement in the buried northern Gawler Craton, South Australia. Precambrian Research 250, pp 127-142.
Reid, A. J., Jagodzinski, E. A., Fraser, G. L. & Pawley, M. J. 2014b. SHRIMP U-Pb zircon age constraints on the tectonics of the Neoarchean to early Paleoproterozoic transition within the Mulgathing Complex, Gawler Craton, South Australia. Precambrian Research 250, pp 27-49.
Smits, R. G., Collins, W. J., Hand, M., Dutch, R. & Payne, J. 2014. A Proterozoic Wilson cycle identified by Hf isotopes in central Australia: Implications for the assembly of Proterozoic Australia and Rodinia. Geology 42, pp 231-234.
Wade, C. E., Reid, A. J., Wingate, M. T. D., Jagodzinski, E. A. & Barovich, K. 2012. Geochemistry and geochronology of the c. 1585 Ma Benagerie Volcanic Suite, southern Australia: Relationship to the Gawler Range Volcanics and implications for the petrogenesis of a Mesoproterozoic silicic large igneous province. Precambrian Research 206–207, pp 17-35.
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