Onyx Gold drills 0.7 g/t Au over 46.7 m at Flipper, confirms zone 3 km south

First-pass drilling opens a new exploration domain along an emerging multi-kilometer Argus Fault corridor at Munro-Croesus

Vancouver, British Columbia--(Newsfile Corp. - October 5, 2026) - Onyx Gold Corp. (TSXV: ONYX) (OTCQX: ONXGF) (" Onyx " or the " Company ") is pleased to report results from the Company's first systematic drill program at the Flipper Zone (" Flipper "), located approximately 3 kilometers south of the Argus Gold System (" Argus ") at its 100%-owned Munro-Croesus Project (" Munro-Croesus " or the " Project "), located 75 kilometers east of Timmins, Ontario.

The six-hole (6), 2,172-meter first-pass program confirms broad and locally higher-grade gold mineralization within sedimentary rocks south of Argus, demonstrating that this extensive and historically underexplored geological package can host broad widths of gold mineralization. Drill hole MC26-277 returned 0.7 g/t Au over 46.7 m , including 4.0 g/t Au over 5.0 m , including 13.5 g/t Au over 1.0 m , with a second interval of 0.2 g/t Au over 44.0 m .

The broader significance is regional. Onyx interprets Flipper to lie along an emerging northeast-trending Argus Fault corridor extending for several kilometers from the Tamarack deposit on adjacent McEwen Inc. property, through Flipper and the historic Stewart-Abate Mine area, across recently acquired Onyx ground and toward Argus (see Figures 1 and 2 ). Large portions remain sparsely explored, providing a substantial new search area outside the known Argus system. Priority areas occur where the corridor intersects quartz-feldspar porphyry (" QFP ") and related intrusive rocks within the sedimentary rocks of the Porcupine assemblage. This opportunity also fits a broader exploration shift in the Abitibi, where recent success has renewed attention on sedimentary packages that historically received less exploration than the camp's vo