Terra Southwest sulphide to surface: open-pit and strip ratio notes for mine planners
Reviewed by Joe Ashwell

First reported on Australian Mining
30 Second Briefing
Terra Metals has intersected 157m of PGM sulphide mineralisation from 5m downhole at the Southwest discovery in the Dante project, West Musgrave, confirming the Southwest Main Zone system extends almost to surface. The intercept, the widest yet from Southwest, averages 0.73g/t platinum plus associated PGMs, indicating a laterally extensive, near-surface sulphide body with potential for bulk-tonnage, open-pit extraction. For geologists and mine planners, the shallow 5m collar depth and continuous 157m mineralised interval materially improve strip ratio assumptions and early-stage project economics.
Technical Brief
- Drillhole at Southwest Main Zone is within the Dante PGM project in WA’s West Musgrave.
- Mineralisation is described as PGM sulphide, implying potential for bulk-tonnage disseminated rather than narrow-vein mining.
- Near-surface sulphides reduce pre-strip requirements, improving early cashflow potential for any future open pit.
- Shallow intercept geometry would favour conventional truck–shovel mining over high-cost underground methods.
- West Musgrave setting suggests remote logistics, so low strip ratios materially affect haulage and fuel economics.
- PGM sulphide style is typically amenable to standard flotation, simplifying potential concentrator design and OPEX assumptions.
Our Take
The Dante project has already shown copper–nickel–cobalt sulphides in earlier drilling in Western Australia’s West Musgrave region, so adding near-surface platinum-group mineralisation at the Southwest discovery strengthens the case for a polymetallic system that could support multiple revenue streams from a single mining footprint.
Starting mineralisation from about 5 m downhole at the Southwest Main Zone suggests any future development could consider shallow open-pit options, which in our database typically lowers upfront unit mining costs compared with deeper PGM operations that rely on underground access.
Within our Mining projects coverage, platinum and broader platinum-group metal stories are relatively sparse compared with iron ore or gold, so Terra Metals’ WA exposure to PGMs at Dante gives it a differentiated commodity profile among Australian juniors focused on battery and base metals.
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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