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.
Geochronology
The principal instrumentation for zircon U-Pb geochronology utilised by GSSA is Sensitive High Resolution Ion Microprobe (SHRIMP) via a National Geoscience Agreement with Geoscience Australia. Details of the SHRIMP instrument at Geoscience Australia
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.
Publications
Jagodzinski EA and Reid AJ 2015. PACE Geochronology: Results of collaborative geochronology projects, 2013–2015.
Jagodzinski EA and Reid AJ 2016. U-Pb geochronological data from drill holes Nundroo 3 DDH and Nundroo 2 DDH, Fowler Domain, western Gawler Craton.
Jagodzinski EA, Reid AJ and Dutch RA 2013. Zircon and monazite geochronology via SHRIMP and LA-ICPMS for the northern Gawler Craton, from 2009 GOMA Drilling.
Dutch RA, Payne JL, Woodhouse AJ and Mason DR 2013. Sm-Nd and Hf isotopic data of the Tieyon (5645) 1:100 000 mapsheet.
Jagodzinski EA and Dutch RA 2013. SHRIMP U-Pb geochronology of the Tieyon (5645) 1:100 000 mapsheet.
Reid AJ and Jagodzinski EA 2012. PACE Geochronology: Results of collaborative geochronology projects 2011-12.
Reid AJ and Jagodzinski EA 2011. PACE Geochronology: results from collaborative geochronology projects 2009-2010.
Aeolian influences in National Geochemical Survey of Australia results from northeastern SA. MESA Journal 74, pp 23-30
The Beda Basalt: new geochemistry, isotopic data and its definition. MESA Journal 73, pp 24-41
PACE Geochronology: extending our understanding of the age and context of mineral systems. MESA Journal 69, pp 58-65
Hf isotopic investigation into the provenance of zircons in heavy mineral sand deposits of the Eucla Basin. MESA Journal 68, pp 17-24
Nature and timing of Cu-Au-Zn-Pb mineralisation at Punt Hill, eastern Gawler Craton. MESA Journal 60, pp 7-17
Extent of low-grade Archaean metavolcanics in the northeastern Gawler Craton: new evidence and definition of the Devils Playground Volcanics. MESA Journal 64, pp 9-19
The Mulgathing and Sleaford complexes of the Gawler Craton: a historical perspective of the geology and mineral potential. MESA Journal 52, pp 4-12
Crustal architecture during the early Mesoproterozoic Hiltaba-related mineralisation event: are the Gawler Range Volcanics a foreland basin fill? MESA Journal 51, pp 19-24
Nature of the Kimban Orogeny across northern Eyre Peninsula. MESA Journal 51, pp 25-34
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.
