What Led to the Julimar Discovery?
The Julimar discovery, located just 70 kilometers northeast of Perth, stands as one of Australia's most significant mineral finds in recent decades. This world-class deposit remained hidden in plain sight until 2020, when Chalice Mining's systematic exploration efforts finally revealed what had been overlooked by generations of geologists.
The discovery story combines strategic corporate decisions, methodical exploration techniques, and the geological insight to challenge conventional wisdom about Western Australia's mineral exploration importance. But what exactly created the conditions for this remarkable find?
The Corporate Foundation That Enabled Discovery
Chalice Mining's ability to make the Julimar discovery stemmed from several key corporate factors that distinguished the company from its peers in the junior exploration sector.
Strong financial position played a crucial role in enabling the discovery. By 2017, Chalice had accumulated approximately $45 million in cash through strategic gold project transactions, providing a substantial treasury that allowed the team to pursue generative exploration without immediate fundraising pressure.
As Alex Dorsch explained, "We pivoted to generative exploration in 2017–18 after frustration with acquisition opportunities… We preferred larger land holdings to open up districts, not chase small-scale finds."
This shift to generative exploration represented a strategic pivot. Rather than competing for known deposits in an increasingly crowded market, management chose to develop their own exploration targets from first principles.
The company maintained a risk appetite with discipline that balanced high tolerance for geological uncertainty with commercial focus. This approach enabled quick decision-making when opportunities arose, as demonstrated when they secured the Julimar tenement within 24 hours of identifying the target.
Morgan Fussell noted that "Tim Goord's support was instant. We pegged the ground in 24 hours because of management's risk appetite," highlighting the advantage of having leadership that understood and supported rapid action on promising concepts.
A flat organizational structure proved invaluable, as decision-making occurred without bureaucratic layers. Geologists had direct access to management and the board, allowing technical concepts to be rapidly evaluated and resourced when warranted.
The company's values-driven culture emphasized urgency, ownership mentality, and technical excellence. As Dorsch observed, "Culture eats strategy for breakfast… Our flat structure let geologists challenge ideas directly," creating an environment where exploration professionals could pursue frontier concepts with adequate funding and support.
How Was the Julimar Target Identified?
The identification of Julimar as a prospective target represents a masterclass in conceptual thinking and data integration. The exploration team combined fundamental geological principles with creative data analysis to see potential where others had seen nothing of interest.
The Craton Margin Concept
The conceptual targeting that led to Julimar began with a fundamental geological principle: craton margins often host significant mineral systems. This thinking was influenced by previous major discoveries in Western Australia.
The team drew inspiration from the Tropicana gold deposit and Nova-Bollinger nickel discovery, both located on craton margins in Western Australia. These precedents suggested that the boundaries between ancient crustal blocks could be highly prospective for mineral deposits.
What made their approach innovative was focusing on an underexplored terrain – the western margin of the Yilgarn Craton had received minimal exploration for magmatic nickel-copper systems despite its geological similarity to other productive craton boundaries.
The catalyst moment came in January 2018 with an ASX announcement about Cassini Resources acquiring the Yarawindah Brook project with PGE mineralization. As Morgan Fussell described it, "The ASX release triggered a eureka moment… We realized PGE-fertile intrusions might exist along the western Yilgarn margin."
This announcement prompted the team to reconsider the entire western margin of the Yilgarn Craton as prospective for mafic-ultramafic intrusions with potential for nickel-copper-PGE mineralization.
Data Analysis and Target Generation
The initial targeting process utilized multiple datasets to identify the Julimar prospect, with the team looking beyond conventional interpretations.
When examining magnetic data, they identified a warm magnetic feature suggesting a potential mafic intrusion. This feature had been previously overlooked or dismissed because the official geological mapping classified the area as granite.
The gravity data revealed a discrete gravity anomaly coincident with the magnetic feature, further supporting the hypothesis of a dense mafic-ultramafic body hidden beneath the surface.
The target's structural context was compelling – it sat near the intersection of the Yilgarn Craton margin and a major northwest structure, creating the kind of structural complexity that often controls mineralization.
In a clever use of existing data, the team noted elevated geochemical indicators including high chromium values in laterite samples from previous CRC LEME programs, suggesting the presence of ultramafic rocks beneath the weathering profile.
Most innovatively, they utilized earthquake data to map deep structures in an area with limited geological mapping. As Fussell explained, "We used earthquake depth data to map structures where GSWA mapping was poor," demonstrating their willingness to incorporate unconventional datasets.
These datasets contradicted the official geological mapping, which had classified the area as granite. The team hypothesized the presence of a large layered mafic-ultramafic intrusion with potential for nickel-copper-PGE mineralization at its base – a bold interpretation that challenged established views.
The Systematic Exploration Approach
Once the target was identified, Chalice Mining implemented a methodical, stage-gated exploration approach that balanced urgency with thoroughness. This systematic process was crucial to the ultimate discovery.
Tenement Acquisition and Initial Research
The team moved with remarkable speed to secure the ground, with Morgan Fussell noting that the "tenement application was submitted within 24 hours of identifying the target." This rapid action ensured they controlled a potentially significant mineral discovery before competitors could recognize its value.
After securing the tenement, they conducted thorough historical review, analyzing previous exploration data that revealed weakly mineralized gabbro with a 2:1 nickel-to-copper ratio and sulfidic sediments. These subtle indicators suggested a potentially fertile system with appropriate sulfur saturation – a critical factor for nickel sulfide deposits.
Their geological reinterpretation directly challenged the prevailing view that the area contained only granite, demonstrating intellectual courage to question established interpretations.
Field Reconnaissance and Orientation Survey
After securing the tenements in late 2018, the team conducted initial fieldwork to validate their conceptual targeting.
They implemented a sophisticated sampling strategy, testing different fractions and analytical methods to determine the most effective approach for detecting mineralization through the weathered profile. The 80-mesh soil fraction proved particularly effective at highlighting anomalous metals.
For target validation, they compared results between the interpreted primitive feeder zone and more fractionated portions of the intrusion, confirming their geological model through field data.
The geochemical confirmation was encouraging, with samples showing 3-10 times background levels of nickel and copper in the target area. One particularly strong anomaly returned 18,800 ppm copper and 700 ppm nickel – values that strongly suggested mineralized bedrock.
Field teams also found physical evidence in the form of outcrops of diorite and gabbro-diorite, confirming the presence of mafic rocks where granite had been mapped, lending further credibility to their reinterpretation.
Geophysical Surveying
The exploration progressed to geophysical methods designed to detect massive sulfide bodies at depth.
A moving loop EM survey was conducted over a one-week period with 200m line spacing and 350m stations. This relatively fast and cost-effective technique was ideal for detecting conductive sulfide bodies at depth.
The survey successfully identified eight EM plates, with two high-priority targets standing out for their conductance and geometry. The primary target was particularly promising – a 12,000 siemens short-strike conductor with characteristics ideal for massive sulfides, alongside a secondary 5,000 siemens conductor.
The entire pre-drilling program cost less than 50% of the initial budget, demonstrating the team's efficient use of resources while still gathering high-quality data.
Surface Geochemistry Over Conductors
To further derisk the project before committing to expensive drilling, the team conducted targeted geochemical sampling over the conductors.
They implemented a hybrid sampling approach using auger drilling in paddocks and soil sampling in native vegetation to overcome the challenges of varied terrain and land use.
PXRF analysis allowed rapid field analysis of samples to guide decision-making in real-time, accelerating the exploration process by eliminating laboratory delays for preliminary results.
The work delivered strong anomaly confirmation with coincident nickel-copper anomalies detected directly over the EM conductors, providing multiple, independent lines of evidence supporting the drill targets.
The team conducted careful contamination assessment to ensure anomalies were genuine and not related to cultural features, fences, or other man-made sources.
The Discovery Moment
In early 2020, after methodical target development and validation, the team was ready to drill test the targets. What followed was the kind of success that most explorers only dream about.
The first-hole success represented an extraordinary validation of the targeting methodology. The initial RC drill hole intersected massive sulfide mineralization exactly where predicted by the geophysical model.
The discovery hole returned exceptional grades: 19 meters at 2.6% nickel, 1% copper, and 8.4 g/t palladium – numbers that would be considered exceptional in any mineral exploration program.
As Morgan Fussell colorfully described, there was immediate visual confirmation when "Henry Steer saw black smoke from the rig… it was massive sulfides" with black sulfide-rich material visible in the cyclone and sample bags. This dramatic moment left no doubt about the significance of the intersection.
The team proceeded with systematic validation, testing the other conductors which confirmed the fertility of the system across multiple locations, rapidly expanding the known mineralized footprint.
In a remarkable coincidence, the discovery occurred just as COVID-19 was beginning to impact global markets, with the first drilling results insights released as the pandemic was taking hold in Australia. Alex Dorsch noted with amusement that the team had to "Google palladium post-discovery—it wasn't on our radar!" as they came to grips with the PGE-rich nature of the mineralization.
What Makes the Julimar Discovery Significant?
The Julimar discovery stands out not only for its size but also for its unique characteristics and broader implications for mineral exploration in Western Australia.
Scale and Grade of the Resource
The Julimar discovery has grown into a world-class mineral resource by any standard.
The substantial resource currently stands at 660 million tonnes containing 17 million ounces of palladium-platinum-gold, 960,000 tonnes of nickel, and 540,000 tonnes of copper – representing one of the largest PGE-nickel-copper resources discovered globally in decades.
A key advantage is the presence of near-surface mineralization, with high-grade fresh sulfide from approximately 40 meters below surface, creating potential for cost-effective open-pit mining.
The deposit has a large footprint measuring 1.9 km by 1 km at surface, extending to 1.1 km depth, with the intrusion maintaining a thickness of approximately 600 meters at depth.
The resource remains open at depth, with the host Gonneville intrusion maintaining significant thickness and showing no signs of pinching out, suggesting potential for resource growth with further drilling.
Geological Uniqueness
The deposit represents a rare style of mineralization with several distinguishing characteristics.
It's a PGE-rich system that is more palladium-dominant than typical Western Australian nickel sulfide deposits. As Alex Dorsch noted, "It's a PGE-rich system, not typical for WA," making it distinct from the more common komatiite-hosted nickel deposits of the eastern goldfields.
The deposit's open-pittable scale is unusual for this style of mineralization, which typically occurs at greater depths. Dorsch emphasized that "open-pittable scale is rare for this style" of magmatic sulfide deposit.
The intrusion has proven to be a remarkably fertile intrusion with multiple zones of mineralization within a large mafic-ultramafic complex, indicating a complex, multi-phase magmatic history conducive to sulfide formation.
Exploration Implications
The discovery has broader implications for mineral exploration in Western Australia that extend far beyond the deposit itself.
Julimar has opened up a new mineral province along the western margin of the Yilgarn Craton as prospective for magmatic sulfide systems. This previously overlooked region now attracts significant exploration investment from multiple companies.
The find prompted a significant geological reinterpretation, with the Geological Survey of Western Australia revising mapping of the southwestern terrain in response to the discovery. What was once mapped as granite is now recognized as a complex of mafic-ultramafic intrusions.
The success validates an exploration methodology that combines conceptual targeting, systematic stage-gated exploration, and the willingness to challenge established geological interpretations – providing a template for future exploration programs.
Key Lessons from the Julimar Discovery
The Julimar discovery offers valuable lessons for mineral explorers that extend beyond the specific geological setting to broader principles of successful exploration.
Challenge Conventional Wisdom
The discovery highlights the importance of questioning established geological interpretations, especially in areas considered "mature" or well-explored.
The proximity paradox is perhaps the most striking aspect – the deposit was found just 70 km from Perth in an area with a high concentration of geologists. That such a significant deposit could remain undiscovered so close to a major mining center underscores the value of fresh thinking.
The team's success came from reinterpreting data, looking beyond official geological maps that classified the area as granite. By integrating multiple datasets and applying first-principles reasoning, they saw potential where others had not.
This fresh perspective allowed them to see opportunity where previous explorers had concluded "there was unlikely to be a significant deposit" – a textbook example of how challenging conventional wisdom can lead to discovery.
Follow Systematic Processes
The exploration success stemmed from a methodical approach that built confidence through staged risk reduction.
The team applied stage-gated exploration, following a logical progression from concept to drilling. As Morgan Fussell emphasized, "Think first, drill after… Systematically derisk or walk away," highlighting their disciplined approach.
They selected fit-for-purpose techniques at each stage, using appropriate methods to answer specific questions rather than applying a one-size-fits-all approach to exploration.
Their strength in data integration combined multiple datasets to build confidence in targets before drilling, creating a compelling case for mineralization that stood up to rigorous internal scrutiny.
Build Strong Relationships
The human element played a crucial role in the discovery, demonstrating that exploration success depends on more than just technical factors.
The team benefited from a collaborative environment that drew on expertise from different team members, combining geological, geophysical, and geochemical insights.
A trust-based culture created space for challenging ideas and open discussion, allowing team members to propose unconventional interpretations without fear of dismissal.
Supportive leadership that understood exploration and provided necessary resources was also critical. As Fussell noted regarding the immediate approval to secure the tenement, management's geological understanding and risk tolerance enabled rapid action.
Balance Speed with Thoroughness
The exploration team maintained momentum while being methodical, neither rushing into drilling nor becoming bogged down in analysis paralysis.
Their rapid initial response secured ground quickly when opportunity was identified, with the tenement application submitted within 24 hours of target identification.
This urgency was balanced with thoughtful progression, taking time to validate targets before committing to drilling. The team spent approximately 10 months on pre-drill validation work, ensuring they had multiple lines of evidence supporting the target.
Once the discovery was made, efficient execution took over, with 1,200 drill holes completed in 3.5 years to rapidly define the resource and its economic potential.
The Future of Julimar and Chalice Mining
The Julimar discovery continues to evolve, with ongoing work to define its full potential and advance toward potential development.
Project Development Path
The Julimar project is advancing through the typical stages of resource development toward a potential mining operation.
A prefeasibility study is nearing completion with expected release in late 2025, which will provide initial economic parameters and development scenarios for the project.
The company is evaluating various processing options through extensive metallurgical testing to determine the optimal flowsheet for extracting the diverse suite of metals present in the ore.
Environmental considerations are at the forefront, with careful management of exploration in areas with dieback disease and other sensitivities. The team has implemented strict protocols for vehicle and gear decontamination to prevent spreading dieback disease in forested areas.
Regional Exploration Potential
Beyond the initial discovery, Chalice has positioned itself to capitalize on the broader potential of the newly recognized mineral province.
The company has expanded its land position, securing a large holding along the western Yilgarn margin to control additional prospective ground with similar geological characteristics.
They're pursuing multiple target styles by exploring for both magmatic nickel-copper-PGE systems similar to Julimar and orogenic gold-copper deposits that might also occur in this geological setting.
Their work contributes to improved geological understanding of the southwestern terrain's mineral potential, benefiting the broader exploration community and advancing scientific knowledge of this previously overlooked region.
What Makes a Successful Explorer?
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