Stories/Discovery replay
Gonneville, hole by hole
In March 2020 a small explorer drilled its first hole into farmland 70 km north-east of Perth and hit nickel, copper and palladium. Replay the years that followed the way the geologists lived them: one release at a time, seeing only what they could see before each next hole.
994 holes and about 305 km of drilling from Chalice Mining's published releases, 2020 to 2025. Palladium intervals light up on the day their assays were published. Straight-line holes from collar angles (no downhole surveys); widths are downhole.
This is a replay of a real discovery from published data, not a game. Each step shows only the holes and assays Chalice Mining (ASX: CHN) had released by that date, so you see what the team could see before choosing the next hole. The lesson running through it is why exploration is hard: many targets fail, the best tools miss things, a single hole can mislead, and turning a hit into a deposit takes hundreds of holes and years.
01 · Late 2019 to March 2020
Before the first hole
What they knew
Chalice held the whole Julimar complex, a body of layered ultramafic and mafic rock about 26 km long and 7 km wide, almost all of it hidden under farmland, soil and forest and never explored for nickel. Magnetics showed a lens-shaped anomaly about 2 km by 0.5 km at its southern end, soil samples were anomalous in nickel and copper, and a moving-loop EM survey in late 2019 found several strong conductors along the lens's margins.
What the drill found
Nothing yet. A four-hole reverse circulation (RC) program was planned to test the conductors labelled A to E. The rings on the map mark roughly where two of them were aimed.
Why it is hard
Geophysics narrows the search but cannot say what a target is made of. A conductor can be nickel sulphide, or pyrite-rich mud, or graphite. The only way to know is to drill it, and every hole costs money a junior explorer may not have.
Source: High-Grade Ni-Cu-Pd Sulphide Intersected at Julimar, Chalice Mining, 23 Mar 2020. · Replay this step
02 · 23 March 2020
The first hole hits
What they knew
One conductor (E) on the south-west margin of the magnetic lens, modelled as a steep plate about 140 m long. Its depth extent could not be modelled because the conductor was too strong.
What the drill found
JRC001 went into fresh rock at about 29 m and at 48 m hit massive sulphide: 19 m at 2.59% nickel, 1.04% copper, 8.37 g/t palladium and 1.11 g/t platinum. Even the weathered rock near surface carried palladium.
Why it is hard
A first-hole hit is rare, and it tells you almost nothing about size. One hole is one pencil line through a body you cannot see: the true width was unknown and the zone was open in every direction. Everything after this is about finding out whether it is a pod or a deposit.
Source: High-Grade Ni-Cu-Pd Sulphide Intersected at Julimar, Chalice Mining, 23 Mar 2020. · Replay this step
03 · 24 March 2020
The strongest target is not ore
What they knew
Conductor A, 900 m north-east of the discovery, looked like the best target of all: a plate about 680 m by 135 m at 214 m depth with a very high conductance of about 5,300 siemens.
What the drill found
JRC002 drilled through gabbro and serpentinite with a few percent disseminated sulphide, then from 241 m into sulphidic sediments full of pyrite and pyrrhotite. That mud, not nickel ore, explained the conductor.
Why it is hard
The biggest, brightest anomaly turned out to be the wrong kind of rock. EM detects conductors, not metal. A day after the discovery, the second hole shows how easily a good-looking target fails.
Source: Preliminary Results from Second Target at Julimar Project, Chalice Mining, 24 Mar 2020. · Replay this step
04 · 15 April 2020
Every hole carries palladium
What they knew
One high-grade hole, one sediment-hosted conductor, and a magnetic lens about 1.6 km long.
What the drill found
All six RC holes assayed so far returned long runs of low-grade palladium, such as 142 m at 0.60 g/t Pd in JRC003 and 119 m at 0.58 g/t Pd in JRC002. JRC006, 60 m east of the discovery, hit a new zone of 41 m at 2.58 g/t Pd. The host was named the Gonneville Intrusive. JRC008 had to be abandoned when the hole bent off course.
Why it is hard
Is a huge low-grade system good news or a distraction? Both. Broad mineralisation hints at scale, but whether it ever pays depends on grade, metallurgy and metal prices years away. Notice too that holes go wrong: drill strings deviate and holes are lost.
Source: Significant Nickel-Palladium Discovery Confirmed at Julimar, Chalice Mining, 15 Apr 2020. · Replay this step
05 · 5 to 11 May 2020
How deep does it go?
What they knew
A magnetic model suggested the base of the intrusion sat about 450 to 530 m down the hole. The ground EM could only see shallow conductors.
What the drill found
JD003 drilled right through the body and logged sulphide almost the whole way, with disseminated sulphide from 270 m to 460 m and the lower contact at about 450 m, close to the magnetic model. New RC holes kept returning broad low grades, such as 137 m at 0.57 g/t Pd in JRC010. A deeper-looking SQUID EM survey was started.
Why it is hard
Each tool sees a slice. Soils see the surface, moving-loop EM a few hundred metres, magnetics the shape of the body. A model that predicts the base of an intrusion and is then confirmed by the drill is a rare, quiet win.
Source: Large-Scale PGE System Further Expanded at Julimar, Chalice Mining, 11 May 2020. · Replay this step
06 · 20 April to 25 May 2020
Two diamond holes, two different stories
What they knew
The discovery zone was thought to dip steeply west. Diamond core was needed to see the rock itself, its textures and its angle.
What the drill found
JD001, drilled to cut the zone 40 m down dip of JRC001, cut only narrow mineralised zones split by barren dykes. JD002 was drilled back the other way as a 'scissor' hole and returned 75.1 m at 6.2 g/t Pd and 1.7% Ni, but it ran almost parallel to the zone, so most of that length is the zone's thickness seen at a low angle.
Why it is hard
Two holes 40 m apart told opposite stories. Late dykes can cut ore out entirely, and a hole drilled along a zone makes it look far wider than it is. That is why releases say 'downhole width, true width unknown', and why one spectacular number is never the whole picture.
Source: High-grade Ni-Cu-PGEs confirmed in discovery zone at Julimar, Chalice Mining, 25 May 2020. · Replay this step
07 · 15 June 2020
Joining the dots
What they knew
Scattered high-grade hits near the discovery, mostly in single holes.
What the drill found
JD003 assays came back with 17.6 m at 5.3 g/t Pd and 1.3% Ni from 191 m. Matrix sulphide had now been seen in six holes, and the team interpreted a continuous zone, named G2, over about 200 m of strike and 100 m of dip.
Why it is hard
A 'zone' is an interpretation drawn between holes, not something anyone has seen. Geologists join intercepts with the geology they log, and the next holes test whether the join was right. Watch how many holes it takes before a shape is trusted.
Source: Extension of Wide High-Grade PGE-Ni-Cu Matrix Zone – Julimar, Chalice Mining, 15 Jun 2020. · Replay this step
08 · 9 July 2020
Something they weren't looking for
What they knew
The working model was nickel-rich massive and matrix sulphide near the discovery, extended to about 200 m of strike.
What the drill found
JD005 ended in a new style of mineralisation at depth: copper-rich palladium-platinum-gold, 23.9 m at 1.7 g/t Pd, 0.7% Cu and 0.5 g/t Au from 315 m, still mineralised when the hole stopped. The G1 to G2 zones grew to about 400 m of strike and 280 m of dip.
Why it is hard
The deposit did not match the model, and the model had to change. Some of the best results at Gonneville came from styles nobody predicted in March. Exploration rewards teams that keep looking at the core rather than only at the target.
Source: Chalice Discovers New High-grade PGE-Cu-Au Zone at Julimar, Chalice Mining, 9 Jul 2020. · Replay this step
09 · 17 August 2020
Following the contact
What they knew
Several stacked zones dipping west, and a new copper-gold style at depth.
What the drill found
The G1 discovery zone was traced over about 400 m of strike and up to 340 m down dip. The copper-rich style, now called G4, appeared in holes 300 m apart along the base (footwall) of the intrusion, including 25.7 m at 3.9 g/t Pd and 2.3 g/t Pt in JD006, with 6.7 m at 10.6 g/t Pd inside it.
Why it is hard
Ore likes contacts. Once a team understands which geological surface hosts the metal, drilling stops being a scatter of guesses and starts tracing that surface. That is the moment a discovery becomes a programme.
Source: Significant Extension of High-Grade Zones at Julimar, Chalice Mining, 17 Aug 2020. · Replay this step
10 · 22 September 2020
When the tool goes quiet
What they knew
Moving-loop EM had found the discovery conductor. Fifty holes were waiting for assays.
What the drill found
An airborne EM survey showed a 6.5 km anomaly (Hartog) running north from Gonneville into the Julimar State Forest. But the company also said plainly that some high-grade zones at Gonneville had no strong EM response at all.
Why it is hard
The method that made the discovery cannot see all of it. Disseminated palladium-rich sulphide conducts poorly, so a target map built only on EM would miss ore. Most of the drilling from here was guided by geology rather than geophysics.
Source: Major New 6.5km-long EM Anomaly Identified at Julimar, Chalice Mining, 22 Sep 2020. · Replay this step
11 · 6 October to 18 November 2020
800 metres out, cut by a dyke
What they knew
Zones G1 to G5 along about 550 m of strike, a footwall zone open to the north, and an EM conductor (X) 800 m to the north-west.
What the drill found
The G4 footwall zone stretched to over 800 m of strike, two new internal zones (G6 and G7) appeared, and an oxide palladium blanket now covered about 1.7 km by 750 m. The 800 m step-out JD018 found the intrusion, but just where the footwall zone should have been, a 20 m dyke had cut it out.
Why it is hard
A step-out hole is a big bet. JD018 was in the right place, at the right contact, and still came back with only 3 m of the target style because younger rock had replaced it. A 'miss' is not always a no.
Source: Significant High-Grade PGE-Cu-Au Extensions at Julimar, Chalice Mining, 18 Nov 2020. · Replay this step
12 · 27 January 2021
The 118 g/t metre
What they knew
Seven high-grade zones in an intrusion now about 1.6 km by 0.8 km, with four rigs drilling.
What the drill found
Step-out and infill holes defined four more zones (G8 to G11). JRC121 returned 11 m at 13.0 g/t Pd, including a single metre at 118 g/t Pd, and G4 passed 1,000 m of strike.
Why it is hard
A one-metre spike makes a headline and moves almost nothing in a resource of hundreds of millions of tonnes. Read the whole interval, the cut-off it was reported at, and how often grades like it repeat.
Source: Julimar Continues to Grow with Four New High-grade Zones, Chalice Mining, 27 Jan 2021. · Replay this step
13 · April to September 2021
The expensive part: the drill-out
What they knew
The shape of a large system, with zones open along strike and down dip.
What the drill found
Up to seven rigs drilled a program of about 160,000 m to infill the zones on a tighter grid. About 125,000 m had been drilled by June 2021, and Chalice bought about 17 km² of private farmland over all the known mineralisation. Zones kept extending, to below 600 m.
Why it is hard
Discovery is a few holes. Proving a resource takes hundreds, drilled close enough together that a competent person can say the zones really connect. This is where most of the money and time goes, and where many discoveries quietly shrink.
Source: Gonneville High-Grade Zones Extended at Depth, Chalice Mining, 28 Sep 2021. · Replay this step
14 · 9 November 2021
A maiden resource
What they knew
Hundreds of published holes, and more drilled than published.
What the drill found
The maiden Mineral Resource: 330 Mt at 0.94 g/t 3E (palladium, platinum and gold), 0.16% Ni, 0.10% Cu and 0.016% Co, about 45% of it Indicated. Chalice described it as the largest nickel sulphide discovery in over 20 years and the largest PGE discovery in Australian history.
Why it is hard
Compare 0.94 g/t with the 8.37 g/t Pd of the first hole. The deposit that may one day be mined is mostly the broad, low-grade rock that looked like a sideshow in April 2020, and the spectacular first intercept is a tiny part of it.
Source: Tier-1 Scale Maiden Mineral Resource at Julimar, Chalice Mining, 9 Nov 2021. · Replay this step
15 · 2 December 2021
A discovery with no signal
What they knew
A resource at Gonneville, and a long airborne EM anomaly to the north.
What the drill found
Drilling found a separate mineralised intrusion just west of Gonneville, such as 3 m at 2.0 g/t Pd and 0.6% Ni in JRC392. It had no EM response at all.
Why it is hard
Even 18 months and hundreds of holes in, the ground still held things no survey had flagged. Blind discoveries are the reason explorers keep drilling between targets.
Source: New Mineralised Intrusion Discovered at Julimar, Chalice Mining, 2 Dec 2021. · Replay this step
16 · 2022 to April 2024
Down plunge, a kilometre deep
What they knew
A resource that had grown with each update, open at depth to the north.
What the drill found
A seismic survey imaged the intrusion continuing north and down plunge, offset by a fault. In July 2023 the step-out JD369W3 hit 54.2 m at 3.6 g/t 3E from 1,133 m down the hole, about 900 m beyond the resource. In April 2024 the resource was remodelled to support selective mining, including a high-grade sulphide part of 59 Mt at 2.0 g/t 3E.
Why it is hard
Deposits rarely end where the first resource stops. But ore a kilometre down is a different, costlier proposition than ore at 50 m, which is why the high-grade part near surface matters more to a mine plan than the deepest hole.
Source: Gonneville Resource Remodeled to Support Selective Mining, Chalice Mining, 23 Apr 2024. · Replay this step
17 · December 2025 to today
Still not a mine
What they knew
Over 700 holes published, a large resource and a plan.
What the drill found
A Pre-Feasibility Study and a maiden Ore Reserve followed in December 2025. As of October 2026 a Feasibility Study is under way and nothing has been mined.
Why it is hard
From first hole to a mining decision takes years, and many good discoveries never get there. Exploration is hard not because ore is rare to touch once, but because proving that it is big enough, rich enough and recoverable enough takes hundreds of holes, years of work and a lot of patience.
Source: Gonneville Palladium-Nickel-Copper Project PFS, Chalice Mining, 8 Dec 2025. · Replay this step
Read the drilling yourself
Every hole here is in the open Gonneville 3D drill model (no sign-in), where you can slide the grade cut-off, open any release and read the intervals. To learn how, start with what exploration drilling is, how to read drill results, drill core and resources and reserves. For the project itself, see the Gonneville project page; for every hole drilled in the state since the 1960s, see Under Western Australia; and for why the road from a discovery to a mine is so long, the history lesson from discovery to production.
Data: Chalice Mining (ASX: CHN) ASX releases, March 2020 to May 2025, as tabulated in our Gonneville drill data (collars, and palladium intervals at the cut-offs printed in each table, including the early 2020 tables checked by hand). A hole appears on the date of the first release that names it, which can be before its assays. Holes without a published interval show grey: most were below the reporting cut-off, and a few were drilled after the company stopped publishing full tables. Holes are drawn straight from their collar dip and azimuth, without downhole surveys, and intervals are downhole widths, not true widths. Resource figures are quoted as the company published them. This page describes published results for learning; it is not investment advice. Satellite imagery is streamed live from Esri World Imagery when shown.
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