Sunday Creek fires first underground decline: design and geotech notes for mine teams
Reviewed by Tom Sullivan

First reported on Australian Mining
30 Second Briefing
Southern Cross Gold Consolidated has started development of an exploration decline at its Sunday Creek gold–antimony project in Victoria, with PYBAR Mining Services firing the first cut on the new portal about 60km north of Melbourne. The decline is the first new underground access in the historic field for roughly 20 years, signalling a shift from surface drilling to underground drilling platforms and bulk sampling. Geotechs and mine planners should expect detailed ground characterisation, ventilation design and water management to follow as the decline advances beneath previously worked structures.
Technical Brief
- Portal establishment with PYBAR implies trackless decline development using modern jumbo and ground support fleets.
- Re-entry into a historic field will require detailed mapping of legacy voids and old workings.
- Antimony association suggests potential for complex metallurgical testwork and deleterious element management in bulk samples.
- Decline geometry will likely be constrained by narrow historic vein trends and existing surface tenement boundaries.
- Ground control strategy must account for old stopes, stress redistribution and possible remnant timbered areas.
- Hydrogeology is likely influenced by historic shafts and adits, increasing uncertainty in inflow pathways and volumes.
- Similar Victorian brownfield declines often trigger early ventilation raises and escapeways to satisfy modern regulations.
Our Take
PYBAR’s work at Sunday Creek in Victoria and Hillgrove in New South Wales (Larvotto Resources, 2025-12-25) shows the contractor is becoming a go‑to specialist for underground gold–antimony access in Australia, which can reduce execution risk for Southern Cross Gold Consolidated as the decline advances.
The strong Apollo intercepts at Sunday Creek reported on 2026-03-16, combined with this first underground access, suggest the project is transitioning from high‑impact drilling towards a more advanced evaluation phase where bulk sampling and closer‑spaced underground drilling can start to define mineable gold–antimony zones.
Within our 1200 Mining stories and 419 keyword‑matched pieces on gold and antimony, Sunday Creek stands out as one of the few Victorian assets explicitly linked to critical‑minerals narratives (antimony for the solar sector), which may help Southern Cross Gold position the project for future government or strategic support beyond conventional gold economics.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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