Integrated Petrophysics: Cloncurry Iron Oxide Cu-Au and related deposits
A major contrast between geophysics in the minerals industry vs oil and gas sectors is the lack of constraint by physical measurements (i.e., petrophysics). Even where petrophysics is undertaken, one or two techniques are typically used and complimentary datasets, which facilitate recognition of underlying processes, are rarely acquired. Our work on the Cloncurry district over the last decade has focused on the development of “Integrated Petrophysics”, a unique, world-leading approach to geoscience, which sets out to relate all geoscience parameters via a scale normalized relational database. It allows us to utilise the huge pool of geoscience knowledge, relate it to physical parameters, and then use those physical parameters to constrain geophysical targeting.
The work was primarily undertaken to explore the complex interrelationships between redox reactions, the formation of magnetic minerals and the magnetic properties and zonation within IOCG and BHT mineral deposits. The methodology has now led to the world’s first, fully integrated, petrophysical-mineralogical-geochemical-structural-metasomatic characterisation dataset, across over twenty deposits from the most geologically complex mineral systems on Earth. This is “complex” data, not “big” data, but used to its full potential it enables the translation of geochemical, structural and geological processes into the physical parameters and required to make big data tangible in the mining space. It allows us to convert geological processes into ones and zeros.
By translating geochemistry to geophysics, we’re addressing major problem in mineral system science, because our largely geochemical approach to mineral exploration is not up-scalable unless converted into physical parameters, or vectors to mineralisation. The work addresses a major oversight in the current Big Data trend in geosciences because it allows us to transform qualitative knowledge into quantitative data, highlighting potential flaws in qualitative knowledge through rigorous science. This work has built up through pilot studies with Ivanhoe Mines (2011), Glencore-Xstrata (2015, and Minotaur Exploration (2014), then the GSQ funded Uncover Cloncurry (2015-2016) an expanded follow-up project Cloncurry METAL (2018-2021) and a spin off Data Analytics project (2020-2022).
Publications
Presentations
Reports
- Austin, J. R., Patterson, B., Birchall, R., Björk, A., Walshe, J., Schlegel T., Stromberg, J., McFarlane, H., Shelton, T.D. and. Pearce, M. (2021) Metasomatic controls on petrophysical zonation in IOCG mineral systems: An example from Ernest Henry, Cloncurry District: Part III: Cloncurry METAL Final Report 2018/21: CSIRO, Australia.
- Austin, J.R., McFarlane, H.B., Schlegel, T. U., Patterson, B., Birchall, R., Walshe, J., Bjork, A., and Shelton, T. D. (2021). Tectono-metasomatic history and structural controls of the Ernest Henry deposit: Insights from integrated mineralogy and magnetic fabric studies: Part IV: Cloncurry METAL final report 2018/2021. CSIRO, Australia.
- Additional Cloncurry METAL reports click HERE, and Uncover Cloncurry Reports click HERE
Toolboxes
- Austin. J., 2021. Petrophysically constrained targeting of Iron Oxide Copper-Gold, Iron Sulphide Copper-Gold and Skarn and Broken Hill Type systems. CSIRO, Australia
- Austin, J.R, 2021. Mapping IOCG Fluid Pathways with Radiometrics: Case Studies, Tools and Exploration Strategy. CSIRO, Australia
- McFarlane, H.B. and Austin, J.R., 2021. Anisotropy of Magnetic Susceptibility (AMS): A powerful tool for quantifying IOCG structural controls and predicting ore body geometries. CSIRO, Australia
Journal Articles
Extended Abstracts
- Austin, J.R., Schlegel, T., Walshe, J., Bjork, A. and Foss, C., 2021. Geophysical proxies for redox gradients in IOCG systems: Cloncurry District, Qld, Australia. AEGC Extended Abstracts, 2021. pp 7.
- Bjork, A., Austin, J.R. and McFarlane, H., 2021. Magnetic characterisation of the Osborne IOCG: magnetic fabrics, self-demagnetisation, and remanence: Cloncurry District, QLD. AEGC Extended Abstracts, 2021. pp 4.
- Austin, J.R., Andreas Björk, A. and Patterson, B.O., 2019. Structural controls of the Ernest Henry IOCG deposit: Insights from integrated structural, geophysical and mineralogical analyses. AEGC Extended Abstracts, 2019:1, pp 5.
- Austin, J.R., 2017. Case Study: Cloncurry District: geophysical properties of IOCG and SEDEX/BHT deposits. Exploration ’17 Workshop: “Improving Exploration with Petrophysics: The Application of Magnetic Remanence and Other Rock Physical Properties to Geophysical Targeting, Toronto, Canada.
- Austin J. R., Schmidt, P. W. and Lilly, R., 2013. Anisotropy of Magnetic Susceptibility (AMS) and Paleomagnetism applied to the differentiation of structural and metallogenic controls on Iron Oxide Copper-Gold (IOCG) mineralization: a case study from Monakoff, NW Queensland. Extended Abstracts, 23rd Annual Australian Society of Exploration Geophysicists Conference and Exhibition, Melbourne.