DTR: $
DTREF: $Introduction
The company acquired the Colosseum Project from Barrick Gold Corporation in 2021, recognising significant gold potential.
The project suspended production in 1993 after producing 344,000 ounces of gold. When mining operations ended in 1992, the mine transitioned to stockpile processing for the last six months of operation. At the time, the gold price stood at US$340 per ounce, roughly 10% of the current spot price
Dateline undertook a comprehensive digitisation and validation of historical data, which had remained dormant for nearly 30 years, before initiating an extensive mineral resource drilling campaign. Diamond drilling confirmed substantial widths of high-grade mineralisation at depth, including 100.6m @ 4.16g/t Au in CM22-05 and 63.2m @ 10.28g/t Au in CM23-08.
In June 2024, the Company announced a JORC-2012 Mineral Resource Estimate of 27.1Mt at 1.26g/t Au (0.0447oz per short ton), equating to 1.1 million ounces of contained gold.
Table 1: June 2024 Mineral Resource Estimate (at 0.5g/t Au cut-off)
|
Category |
Cut-off (g/t Au) |
Metric Tonnes |
Grade (g/t Au) |
Contained Gold |
Percentage |
|
Measured |
0.5 |
9,600,000 |
1.47 |
455,000 |
41% |
|
Indicated |
0.5 |
7,200,000 |
1.21 |
281,400 |
26% |
|
Inferred |
0.5 |
10,300,000 |
1.10 |
364,000 |
33% |
|
TOTAL |
27,100,000 |
1.26 |
1,100,400 |
100 |
Notes:
Project Economics
A Scoping Study released in May 2025 outlined a robust gold mining operation, projecting production of 635,000 ounces over an initial eight years, with net revenues of US$827 million, a NPV6.5 of US$550 million, and an IRR of 61%. The technical aspects of the study were based on a gold price of US$2,200 per ounce, with the economics estimated using a gold price of US$2,900 per ounce.
Table 2: Updated Scoping Study – Estimates of Inputs and Outcomes
|
Parameter |
Unit |
May 2025 Updated Scoping Study |
|
Gold Price |
US$/oz |
2,900 |
|
Discount Rate |
% |
6.5 |
|
PRODUCTION TARGET | ||
|
Life of Mine |
Years |
9 |
|
Total Ore Mined |
M Tonnes |
16.6 |
|
Total Waste Mined |
M Tonnes |
56.8 |
|
Total Material Movement |
M Tonnes |
73.3 |
|
Strip Ratio |
US$/oz milled |
3.4:1 |
|
Total Tonnes Milled |
x:x |
16.6 |
|
Average Plant Throughput |
Mtpa |
1.8 |
|
Average Head Grade |
g/t Au |
1.3 |
|
Average Recovery |
% |
92 |
|
Total Net Gold Produced |
koz |
635 |
|
Ave Annual Gold Production |
Koz pa |
71 |
|
FINANCIALS | ||
|
Total Operating Costs |
US$M |
751 |
|
Total Capital Costs |
US$M |
195 |
|
Total pre-production capital expenditure |
US$M |
138 |
|
Total Net Revenue |
US$M |
153 |
|
Total Sales Revenue (includes royalties) |
US$M |
827 |
|
Discounted Cashflow (@6.5%) – NPV |
US$M |
1,773 |
|
Internal Rate of Return |
% |
550 |
|
UNIT COSTS | ||
|
Unit Operating Costs (C1) |
US$/oz milled |
1,182 |
|
All In Sustaining Costs |
US$/oz |
1,490 |
Bankable Feasibility Study (BFS)
A Bankable Feasibility Study is currently underway for the Colosseum Gold Mine, with development planned within the existing vested Mining Rights and an approved Plan of Operation, with Dateline having the approvals required to recommence mining at Colosseum.
Dateline is aiming to complete the Bankable Feasibility Study in early 2026.
Dependent on the results of the BFS, the Company will seek funding for the construction of the Colosseum Gold Mine with the aim to commence construction in Q2 2026.
Geology and geological interpretation
The Colosseum gold deposit is located at the southern end of the Walker Trend. The project lies within in the Clark Mountain Mining District in the northeast portion of the Clark Mountain Range. The district includes the Mountain Pass rare earth mine six miles south of the Colosseum Mine, numerous abandoned copper mines, and scattered fluorite, antimony, and tungsten prospects.
Most gold and silver deposits in the district are within the northeast quadrant of the district north of Clark Mountain and are associated with emplacement of a felsic breccia complex into Precambrian basement rocks.
The Colosseum deposit itself is associated with the emplacement of a breccia complex into Precambrian gneissic basement rocks. The complex is comprised of two known felsite breccia pipes that form a northeast-southwest elongate zone, which contains mineralised zones of disseminated auriferous pyrite.
Gold at the Colosseum deposit is generally sub-microscopic and associated with sulphide mineralisation, chiefly pyrite. It occurs as free gold, with minor alloyed silver. Gold is primarily in contact with pyrite, in fractures in the pyrite or along pyrite grain edges. It also occurs as isolated particles in quartz and other gangue minerals but spatially always close to pyrite but rarely as particles encased in euhedral pyrite.
The Colosseum deposit style is a hydrothermal breccia pipe with a combination of epithermal mineralisation at original higher levels and mesothermal mineralisation at the lower levels.
3D Interactive Model
Dateline has developed a 3D online interactive model of the Colosseum Gold Mine. Click on the following link to access the model:
Exploration Potential
Nearly all of the historic exploration at Colosseum was focused on the two known breccia pipes, with 1.4Moz of gold (344koz mined and 1.1Moz resources) defined in the upper 250 metres.
In the figure above, lower density (dark blue) and low resistivity (purple) areas are interpreted to identify alluvial fill, alteration, and brecciation of host lithologies. Higher density (red) and high resistivity (blue-white) areas are interpreted to be Early Proterozoic granites possibly including fenitisation and/or carbonatite.
The black triangles denote the new target areas based on this data. The location designated is at the centre of a more extensive geophysical response suggesting considerable extent to the targets. The data also suggests the known mineralisation may extend to the northeast. Black outlines are the pit boundaries and black lines are section locations.
Depth slice at 200m below topography through the 3D density model (left) and resistivity model (right). The new priority targets are labelled 1 to 6 and the positions of the cross sections are also shown.
3D view of the resistivity anomalies draped over the topography of the area, with the relative sizes of the new targets compared to the existing known South Pipe mineralisation
3D resistivity model shown below a draped topography model. The outline of the current South pit is shown along with cross section C-C’ (refer plan above). The resistivity anomalies for some of the new targets demonstrate a higher response than that over the known mineral resources.