<p>Iron oxide-copper-gold (IOCG) mineral systems are a desirable undercover exploration target due to their large alteration footprint and potentially high metal content. To assist in understanding the potential for IOCG mineral systems beneath cover in the Tennant Creek to Mount Isa region as part of Exploring for the Future, a predictive mineral potential assessment has been undertaken using a knowledge-based, mineral systems approach.<p>This mineral potential assessment uses a 2D, GIS-based workflow to qualitatively map four key mineral system components: (1) Sources of metals, fluids and ligands, (2) Energy to drive fluid flow, (3) Fluid flow pathways and architecture, and (4) Deposition mechanisms, such as redox or chemical gradients. For each of these key mineral system components theoretical criteria, representing important ore-forming processes, were identified and translated into mappable proxies using a wide range of input datasets. Each of these criteria are weighted and combined using an established workflow to produce the final map of IOCG potential, all of which is well documented in the accompanying IOCG Assessment Criteria Table.<p>Two assessments have been undertaken. The first is a comprehensive assessment containing all available geospatial information and is highly reliant on the level of geological knowledge. As such, it preferentially highlights mineral potential in well-understood areas, such as outcropping regions and performs less well in covered areas, where there is a greater likelihood of data gaps. The second assessment utilises only datasets which can be mapped consistently across the assessment area. As such, these are predominately based on geophysical data and are more consistent in assessing exposed and covered areas. However, far fewer criteria are included in this assessment.<p>Both assessment highlight new areas of interest in underexplored regions, of particular interest a SW-NE corridor to the East of Tennant Creek of moderate/high potential in the Barkly region. This corridor extends to an area of moderate potential in the Murphy Inlier region near the Gulf of Carpentaria on the NT/QLD border.

The Mineral Potential Mapper (MPM) project represents a significant step forward in identifying new mineral provinces in Australia. The project demonstrated that the apparent under-representation of giant Ni Cu-PGE sulfide resources in Australia was a consequence of concealment of mineral deposits by sediments, basins and regolith (cover) which has hindered exploration success, rather than a lack of geological endowment. The project focused on the identification of prospective regions considered worthy of more detailed work (by exploration companies). The availability of new digital datasets at continental scale enabled the work which predicted a high potential for Ni-Cu-PGE sulfide deposits in a wide range of geological regions across Australia. The project delivered the following outputs: – a technical report providing the first continental-scale assessment of Ni-Cu-PGE mineral potential of Australia applying knowledge-driven geographic information system (GIS)-based prospectivity analysis methods – a series of Geodatabase digital maps (included in the report) – primary digital data and programming script used in the GIS analysis – a workshop delivered in Perth to industry on the 12 June 2016 – a world first National mineral potential map for Ni Cu-PGE sulfide deposits. The MPM materials have generated considerable industry interest. Chalice Mining Limited (Chalice) (formerly Chalice Gold Mines Limited) notes the MPM “… provided valuable input into Chalice’s regional targeting, particularly when applied to frontier areas” (and that) “… recent success at Julimar validates the work by Geoscience Australia (GA) and shows the impact that pre-competitive data can have when applied to greenfields exploration.” Chalice’s Julimar discovery is the world’s largest deposit of its type discovered in 20 years and one of four Tier one deposits discovered in the world in the last five years. It has spurred a significant uptake in tenements by explorers across a green field region and further significant finds are likely. The project has also generated considerable international government interest, sparking the Critical Minerals Mapping Initiative. The United States of America and Canada are both applying similar innovative mineral systems-based assessment methodologies to undertake precompetitive prospectivity mapping at a national scale. Given the impact of the MPM project will only be fully appreciated with the realisation of new mines, ACIL Allen has considered two hypothetical mine development scenarios: development of the Gonneville deposit based on Chalice’s (Australian Securities Exchange) ASX report of 8 July 2022, and a second case with an expansion of the Gonneville deposit (to 500Mt), coupled with a more spectacular discovery (double the size of the Gonneville deposit). Both success case scenarios were modelled using a conservative set of assumptions drawn from Chalice’s ASX reporting, prevailing market figures and industry norms. Based on those assumptions, ACIL Allen estimates that the development scenarios could generate an overall benefit to the Australian economy of between $3.48 billion and $4.57 billion and between $1.21 billion and $1.56 billion in net benefits to the Commonwealth in terms of taxation. GA’s investment in the project ($3.0 million) enabled the creation of these benefits. Indeed, every dollar invested in this project by the Commonwealth through GA could generate between $1,176 and $1,546 in additional benefits to the economy. The estimated benefit-cost ratio (BCR) for the Commonwealth Government is between 409 and 526 for the ‘success cases’. This is a substantial step up from the initial assessment conduct 12 months ago prior to the availability of resource figures for the Gonneville deposit (with a small and a large mine delivering an overall benefit of between $441 million and $869 million, with a BCR between 65 and 127).

Australian iron ore is predominantly exported and used for steelmaking internationally. However, steelmaking is an energy- and carbon-intensive heavy industry, and its electrification in the coming decades will likely disrupt the existing iron ore–steel value chains. Green steel—produced using hydrogen and electricity from renewable energy sources—presents both opportunities and challenges for Australia. Indeed, with abundant renewable energy potential and iron-ore resources, Australia could lead this global transformation. Here, we examine the interrelationships between the Australian iron-ore industry, the production of green-hydrogen from renewable energy sources, and an emergent green steelmaking process. In particular, we undertake detailed case studies to estimate current green steel production costs within two regions; the Pilbara Craton in Western Australia and the Eyre Peninsula in South Australia. While existing technology is not well suited to Australian hematite ores, our analysis highlights the site-specific competitiveness of small-scale, magnetite-fed, off-grid operations. The results underscore the advantages of a well-optimised system in decreasing hydrogen and energy storage requirements, and decreasing production costs. While our results also suggest that grid-connected projects could reduce costs through flexible operation, more work is required to understand the limitations of these conclusions. The results underscore the need to develop technologies to utilise hematite ores in green steelmaking, but also highlight the opportunity for this emerging industry to commercialise Australia’s magnetite resources. <b>Citation: </b>Wang C., Walsh S. D. C., Haynes M. W., Weng Z., Feitz A., Summerfield D., & Lutalo I., 2022. From Australian iron ore to green steel: the opportunity for technology-driven decarbonisation. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://dx.doi.org/10.26186/147005

Green steel, produced using renewable energy and hydrogen, presents a promising avenue to decarbonize steel manufacturing and expand the hydrogen industry. Australia, endowed with abundant renewable resources and iron ore deposits, is ideally placed to support this global effort. This paper's two-step analytical approach offers the first comprehensive assessment of Australia's potential to develop green steel as a value-added export commodity. The Economic Fairways modelling reveals a strong alignment between prospective hydrogen hubs and current and future iron ore operations, enabling shared infrastructure development and first-mover advantages. By employing a site-based system optimization that integrates both wind and solar power sources, the cost of producing green steel could decrease significantly to around AU$900 per tonne by 2030 and AU$750 per tonne by 2050. Moreover, replacing 1% of global steel production would require 35 GW of well-optimized wind and solar photovoltaics, 16 GW of hydrogen electrolysers, and 1000 square kilometres of land. Sensitivity analysis further indicates that iron ore prices would exert a long-term influence on green steel prices. Overall, this study highlights the opportunities and challenges facing the Australian iron ore industry in contributing to the decarbonization of the global steel sector, underscoring the crucial role of government support in driving the growth and development of the green steel industry. <b>Citation:</b> Wang C et al., Green steel: Synergies between the Australian iron ore industry and the production of green hydrogen, <i>International Journal of Hydrogen Energy,</i> Volume 48, Issue 81, 1 October 2023, Pages 32277-32293, ISSN 0360-3199. https://doi.org/10.1016/j.ijhydene.2023.05.041

Following the successful outcomes of the Tennant Creek-Mt Isa (TISA) mineral potential assessment (Murr et al., 2019; Skirrow et al., 2019), the methodology has been expanded to encompass the entire North Australian Craton (NAC). Like its predecessor, this assessment uses a knowledge-based, data-rich mineral systems approach to predict the potential for iron oxide-copper-gold (IOCG) mineralisation. With their high metal yield and large alteration footprint, IOCG mineral systems remain an attractive target in directing exploration efforts towards undercover regions. This mineral potential assessment uses a 2D GIS-based workflow to map four key mineral system components: (1) Sources of metals, fluids and ligands, (2) Energy to drive fluid flow, (3) Fluid flow pathways and architecture, and (4) Deposition mechanisms, such as redox or chemical gradients. For each of these key mineral system components, theoretical criteria representing important ore-forming processes were identified and translated into mappable proxies using a wide range of input datasets. Each of these criterion are weighted and combined using an established workflow to produce a models of IOCG potential. Metadata and selection rational are documented in the accompanying NAC IOCG Assessment Criteria Table. Two scenarios were modelled for this assessment. The first is a comprehensive assessment, targeting pre-Neoproterozoic mineral systems (>1500 Ma), using a combination of interpreted, geological and geophysical datasets. As geological interpretations are subjective to the geological knowledge of the interpreter, well-documented areas, such as shallow pre-Neoproterozoic basement, have a greater density of data. This increase in data density can create an inherent bias in the modelled result towards previously explored shallow terrains. The second assessment utilises only datasets which can be mapped consistently across the assessment area. As such, these are predominately based on geophysical data and are more consistent in assessing exposed and covered areas. However, far fewer criteria are included in this assessment, and observations are reflective of only the modern geological environment. Both assessments highlight existing mineral fields in WA, NT and QLD, and suggest that these regions extend under cover. Furthermore, regions not previously known for IOCG mineralisation display a high modelled potential, offering exploration prospects in previously unknown or discounted areas.