Onyx Gold Returns 194 m of 1.8 g/t Au at Argus North, Including 28 m of 3.0 g/t Au and 24.1 m of 3.7 g/t Au Down-dip Follow-up Demonstrates Excellent Continuity and Consistency Between Drill Holes MC25-232 and MC25-233
December 16th, 2025 NR# 045-2025
NEWS RELEASE
Onyx Gold Returns 194 m of 1.8 g/t Au at Argus North,
Including 28 m of 3.0 g/t Au and 24.1 m of 3.7 g/t Au
Down-dip Follow-up Demonstrates Excellent Continuity and Consistency
Between Drill Holes MC25-232 and MC25-233
Vancouver, BC – December 16th, 2025 – Onyx Gold Corp. (“Onyx” or the "Company") (TSX-
V: ONYX, OTCQX: ON XGF) is pleased to additional drill results from Company’s ongoing drill
program (the “ Program”) at its 100% -owned Munro-Croesus Project (“ Munro-Croesus” or the
“Project”), located 75 km east of Timmins, Ontario. Results reported today include those from two
(2) drill holes completed at the Argus North Zone (“ Argus North ”) and seven (7) drill holes
targeting the Argus Main Zone (“Argus Main”), located 100 meters (“m”) south and up to 300 m
east of Argus North.
Key results include those from drill hole MC25-233, which was drilled 30 m below and on-section
with previously reported drill hole MC25-232 which returned 208 m grading 2.3 grams per tonne
gold (“g/t gold”) (see Company news release dated November 17, 2025). Holes MC25-232 and
MC25-233 are part of a series of planned northwest oriented holes designed to drill perpendicular
to a recently defined northeast-trending structural corridor beneath the key Argus North outcrop
exposed by mechanical stripping earlier this year. This developing concept of a strong northeast-
southwest structural control on higher -grade gold distribution within Argus North is based on
detailed geological mapping, surface channel sampling and 3D modeling by the Company’s
technical team.
The assay results from hole MC25-233 returned 194.0 m grading 1.8 g/t Au, followed by a
second lower interval that returned 60.7 m grading 1.3 g/t Au. These results reinforce the
concept of the northeast-southwest structural controls on higher-grade gold mineralization at
Argus North and have successfully extended the gold mineralization intersected in hole MC24-
233 to depth.
Highlights
• Drilling at Argus North returned 194.0 m grading 1.8 g/t Au, in d rill hole MC25- 233,
including
o 28.0 m grading 3.0 g/t Au, including
2.0 m grading 9.1 g/t Au, and
o 24.1 m grading 3.7 g/t Au, including
2.0 m grading 9.0 g/t Au
• Followed by a second lower interval that returned 60.7 m grading 1.3 g/t Au, in drill hole
MC25-233, including
o 18.2 m grading 2.7 g/t Au, including
7.1 m grading 3.7 g/t Au
• Drilling at Argus Main returned broad near-surface mineralization over 200 m strike ,
with high-grade sub-intervals up to 10.5 g/t Au
• Ongoing step-out drilling at the Argus North, Main and West discoveries has now defined
broad zones of gold mineralization over a total strike length of 900 m and from surface
to ~400 m vertically
• All of the Argus Zones (North, Main and East) remain open along strike, down-dip, and
down-plunge
• The Company has completed 100 drill holes to date, totalling > 36,000 m as part of its
75,000 m Phase I/II/III drill program. Assays have been announced for 53 holes
• With ~$30 M in the treasury, the Company remains fully funded to advance its 2026
exploration programs
“These impressive results reinforce the strength of mineralization at Argus North and continue to
validate our evolving geological model ,” said Brock Colterjohn, President & CEO of Onyx Gold.
“With mineralization now traced from surface to over 400 m depth and remaining open in several
directions, Argus North continues to grow in scale and significance with each phase of drilling.”
“At Argus Main, the latest drilling continues to demonstrate the broad footprint and near -surface
continuity of gold mineralization along the Pipestone Fault corridor . These results confirm the
presence of consistent gold grades over meaningful widths and highlight the potential for higher-
grade structural controls within a shallow, large, bulk-tonnage system.”
Discussion of 2025 Argus North Drill Results
The Argus North Zone is located on the western half of the Munro-Croesus Project, approximately
150 metres north of the regional Pipestone Fault, a major structural corridor that hosts several
significant gold deposits in the Timmins camp. The discovery hole at Argus North, MC24-163, was
reported earlier this year, and returned 69.6 m grading 3.4 g/t Au, including 34.5 m grading 5.4
g/t Au and 9.5 m grading 13.9 g/t Au (see Company news release dated April 10, 2025).
Gold mineralization at Argus North is distinguished by both broad zones (50 m to over 100 m) of
+1 g/t Au mineralization containing multiple continuous higher -grade sub-intervals. The higher-
grade sub-intervals are closely associated with zones of strong albitization and silicification, pyritic
stringers, and localized porphyritic intrusions within variolitic basalt and volcanic breccias cut by
dominant steeply dipping, northeast-trending faults and associated fractures. This combination of
alteration and structural preparation is interpreted to be a key control on gold deposition.
Results reported today include hole MC25-233, which was drilled 30 meters below and on-section
with drill hole MC25- 232, which intersected 208 m grading 2.3 g/t Au. Hole MC25-233 has
returned another very strong intersection with 194.0 m grading 1.8 g/t Au , including two
subintervals 28.0 m grading 3.0 g/t Au and 24.1 m grading 3.7 g/t Au, and a separate lower
zone of 60.7 m grading 1.3 g/t Au, including 7.1m grading 3.7 g/t Au.
Holes MC25-232 and MC25-233 are part of a series of planned northwesterly-oriented drill holes
designed to drill perpendicular to a recently defined northeast-trending structural corridor beneath
the Argus North outcrop . This drilling strategy developed from the compilation of months of
detailed geological mapping, surface channel sampling results, and 3D geological modeling that
suggests a strong northeast-southwest structural control on higher-grade gold distribution. A third
drill hole on the same cross -section, MC25-231, drilled 30 m above hole MC25- 232, still has
assays pending.
Drilling to date demonstrates excellent vertical continuity of gold mineralization, now traced over
a strike length of 900 meters and from surface to over 400 meters depth, with the system
remaining open along strike, down-dip, and down-plunge.
The Argus North Zone remains open along strike, down-dip, and down-plunge and the opportunity
to expand the zone through ongoing drilling is considered excellent.
Details for drill hole assays reported in this news release are shown in Figures 1 through 5 and
Tables 1 and 2.
Table 1 – Significant Assay Results from 2025 Drilling Completed at the Argus North Zone
Target From To Length Au
Drill Hole (m) (m) (m) (g/t)
Argus North
MC25-233 67.0 261.0 194.0 1.8
Including 72.5 202.5 130.0 2.4
Including 72.5 100.5 28.0 3.0
Including 75.5 76.3 0.8 9.7
And Including 87.5 100.5 13.0 4.0
Including 87.5 88.0 0.5 12.7
And Including 93.5 95.5 2.0 9.1
And Including 140.0 164.1 24.1 3.7
Including 144.0 146.0 2.0 9.0
And Including 159.0 160.0 1.0 10.7
And 347.9 408.6 60.7 1.3
Including 347.9 366.1 18.2 2.7
Including 359.0 366.1 7.1 3.7
And Including 404.0 408.0 4.0 1.9
MC25-203 69.8 101.7 32.0 0.3
Including 80.0 85.0 5.0 0.9
*Intersections are reported as drilled width; true width is estimated to be 70-90% of drilled width.
Figure 1 – Plan Map Highlighting Argus North Zone Drill Holes Reported in this Release
Figure 2 – Long Section Highlighting Argus North Zone Drill Holes Reported in this
Release – Looking East
Figure 3 – Long Section Highlighting Argus North Zone Drill Holes Reported in this
Release – Looking East
Figure 4 – Cross-Section 600E Highlighting Argus North Zone Drill Holes Reported in this
Release – Looking East