Onyx Gold Drills 1.1 g/t gold over 194.4m Cumulative Thickness in Step-Out Hole at Argus North Zone, Munro-Croesus Project Drilling Confirms Vertical and Lateral Extensions of Argus North, Highlighting System Scale and Continuity
September 3rd, 2025 NR# 032-2025
NEWS RELEASE
Onyx Gold Drills 1.1 g/t gold over 194.4m Cumulative Thickness in
Step-Out Hole at Argus North Zone, Munro-Croesus Project
Drilling Confirms Vertical and Lateral Extensions of Argus North, Highlighting
System Scale and Continuity
Vancouver, BC – September 3rd, 2025 – Onyx Gold Corp. (“Onyx” or the "Company") (TSX-V:
ONYX, OTCQX: ON XGF) is pleased to announce additional drill results from the Company’s
ongoing 25,000 metre drill program (the “Program’) at its 100% owned Munro-Croesus Project
(“Munro-Croesus” or the “Project”), located 75 km east of Timmins, Ontario.
Results are reported today for eight (8) step-out holes drilled on a cross-section located 50 metres
west of the Argus North discovery section. This new drilling builds on results reported in June
2025, where four (4) holes included standout intercepts such as 91.0 m grading 1.8 g/t Au,
including 32.0 m of 4.0 g/t Au in hole MC25-168 and 59.7 m grading 2.5 g/t Au including 18.7
m grading 5.2 g/t Au in drill hole MC25-171 (see Company news release dated June 26, 2025).
Highlights
• 91.0 m grading 1.1 g/t Au including 4.0 m grading 4.6 g/t Au, and a second deeper
intersection of 103.4 m grading 1.1 g/t Au including 38.4 m grading 2.4 g/t Au, in drill
hole MC25-177 for a total cumulative width of 194.4 meters of mineralization.
• 139.1 m grading 0.8 g/t Au including 6.9 m grading 4.3 g/t Au, in drill hole MC25-181, a
50 m down-dip step-out from drill hole MC25-177.
• 9.8 m grading 2.9 g/t Au including 2.2 m grading 11.8 g/t Au, in drill hole MC25-174,
within the Argus Main Zone.
• 35.0 m grading 1.1 g/t Au including 7.0 m grading 3.4 g/t Au, in drill hole MC25-187A,
• Step-out drilling at Argus North continues to demonstrate wide intervals of promising
gold mineralization over >100 meters of strike length (CS 50 W to CS 50 E) and from
surface to >350 meters vertically.
• The Company has completed 48 drill holes (assays announced for 15 holes to date)
completing approximately 15,000 m (60%) of the expanded 25,000 m Program.
• With approximately $10 M in cash, the Company remains fully funded for all its 2025
exploration programs.
• The Argus North Zone is open along strike, down-dip and down-plunge. Ongoing plans
include step-out drilling along strike on 50-m to 100-m spaced cross-sections designed to
extend the limits of the known gold mineralization.
“Our latest drilling at Argus North continues to demonstrate broad zones of gold mineralization
with multiple higher-grade subintervals,” said Brock Colterjohn, President & CEO of Onyx Gold.
“Intersecting nearly 200 metres of cumulative mineralization in a single hole underscores the scale
of the system, while the presence of higher-grade sub-intervals within these broader envelopes
highlights the strength of the gold system. Importantly, mineralization has now been traced from
surface to over 300 metres depth and remains open along strike and down-plunge.”
“The Munro-Croesus project benefits from excellent infrastructure, with all reported gold results
located beneath or adjacent to existing logging roads, less than 2 km away from Highway 101
and accessible year-round. With roughly half of our expanded 25,000-metre program still to come,
we believe Argus North is only beginning to demonstrate its potential as the Timmins Camp’s
newest gold discovery.”
Discussion of 2025 Argus North 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. Discovery hole M C24-163, reported earlier this
year, 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). Argus North lies roughly 100
metres north of the east-west trending Argus Main Zone, which represents a separate 750 m x
200 m near-surface bulk-tonnage gold target (e.g., 1.0 g/t Au over 63.3 m and 0.5 g/t Au over 136
m).
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. Notable recent
high-grade intercepts include 17.0 m grading 5.3 g/t Au in hole MC25-168, 18.7 m grading 5.2
g/t Au in MC25-171, 5.2 m grading 5.1 g/t Au and 6.6 m grading 4.2 g/t Au in MC25-178, 4.0
m grading 6.6 g/t Au in MC25-179, 4.0 m grading 5.9 g/t Au in MC25-180, and 4.0 m grading
4.6 g/t Au in MC25-177. For context, interc epts of this grade and thickness , in addition to the
broad zones of +1 g/t Au mineralization, compare favorably with those reported from other major
gold deposits in the Timmins camp, underscoring the potential significance of Argus North as a
material new gold discovery in the district.
Geologically, the high-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. This combination of alteration and structural preparation is interpreted to be a
key control on gold deposition. Drilling to date demonstrates excellent vertical continuity of
mineralization, now traced from surface to over 3 50 meters depth, with the system remaining
open along strike, down-dip and down-plunge.
The eight (8) drill holes reported in this news release are all located within 25 m of the same north-
south cross-section, situated 50 m west of previously reported drill holes MC24-163/168/171 (see
Figure 1, Figure 2 and Figure 3 ) with approximate 50 m step-outs up-dip and down-dip. The
drilling to date has continued to return encouraging results with drill holes MC25-177 and MC25-
181 both intersecting plus 100-meter widths of consistent gold mineralization as reported below
and in Table 1. The Argus North Zone remains open along strike, down-dip and down-plunge and
ongoing plans will continue to see step-out drilling along strike on 50-m to 100-m spaced cross -
sections to extend the limits of the known gold mineralization.
Argus North Zone
• 91.0 m grading 1.1 g/t Au, in hole MC25-177 (50 m west of drill hole MC25-163), including
o 27.0 m grading 2.0 g/t Au, including
4.0 m grading 4.6 g/t Au, AND
• 103.4 m grading 1.1 g/t Au, also in hole MC25-177, including
o 38.4 m grading 2.4 g/t Au, including
7.0 m grading 3.4 g/t Au
• 53.5 m grading 0.8 g/t Au, in hole MC25-181(50 m down-dip from MC25-177), including
o 18.7 m grading 1.2 g/t Au, including
4.8 m grading 2.2 g/t Au
• 139.1 m grading 0.8 g/t Au, also in hole MC25-181, including
o 8.5 m grading 2.2 g/t Au, including
4.9 m grading 3.1 g/t Au, AND
o 23.5 m grading 1.7 g/t Au, including
6.9 m grading 4.3 g/t Au
• 16.0 m grading 1.0 g/t Au, in hole MC25-176A (50 m up-dip from MC25-177), including
o 4.5 m grading 2.5 g/t Au
• 35.0 m grading 1.1 g/t Au, in hole MC26-187A (25 m east and behind the cross-section),
including
o 7.0 m grading 3.4 g/t Au, in drill hole MC25-187A
Argus Main Zone
• 9.8 m grading 2.9 g/t Au, in hole MC25-174, including
o 2.2 m grading 11.8 g/t Au
Note - Drill holes MC25-169 and MC25-170 returned no significant values at Argus North.
The Company has completed 48 drill holes (assays announced for 15 holes to date) completing
approximately 15,000 m (60%) of the expanded and fully funded $10 M, 25,000 m Program.
Figure 1 – Cross-Section Highlighting Drill Holes Reported in this Release – Looking East
Figure 2 – Longitudinal-Section Highlighting Drill Holes Reported in this Release –
Looking North
Figure 3 – Plan Map Highlighting Argus North Zone Drill Holes Reported in this Release
Figure 4 – Location of the Munro-Croesus Gold Project, Ontario
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
MC25-169 No Significant Values
MC25-170 No Significant Values
MC25-172 110.3 112.5 2.2 1.1
And 247.1 252.0 4.9 0.6
Including 247.1 248.0 0.9 2.4
And 287.0 298.0 11.0 0.5
Including 287.0 288.0 1.0 2.7
And Including 297.0 298.0 1.0 1.6
MC25-174 74.5 75.5 1.0 2.0
And 229.3 239.0 9.8 2.9
Including 236.8 239.0 2.2 11.8
Including 238.1 239.0 0.9 23.3
And 304.0 321.0 17.0 0.6
Including 305.0 313.6 8.6 1.2
Including 305.0 306.0 1.0 4.2
MC25-176A 37.4 72.0 34.6 0.4
Including 44.4 58.5 14.1 0.7
Including 46.2 54.5 8.3 1.1
And 104.0 105.0 1.0 8.0
And 214.0 230.0 16.0 1.0
Including 218.0 222.5 4.5 2.5
Including 221.0 222.5 1.5 4.9
And 255.0 264.0 9.0 1.1
Including 255.0 257.0 2.0 2.4
And 353.5 355.0 1.5 1.3
MC25-177 53.0 103.0 50.0 0.3
Including 79.0 90.0 11.0 0.9