Great Western spots possible VHMS edge at Seymour
Great Western Exploration has identified zinc-silver-lead mineralisation at its Seymour target in Western Australia, which it interprets as the outer edge of a potentially fertile volcanic-hosted massive sulphide system. The company says a nearby copper-gold core remains untested and is accelerating permitting, geophysics and follow-up drilling.
- 12m at 0.33% zinc, 7.1g/t silver and 0.09% lead from 77m
- Higher-grade sub-intervals include 1m at 1.02% zinc and 2m at 20.2g/t silver
- Seymour is interpreted as the cooler margin of a VHMS mound system
- Follow-up drilling, airborne magnetics and potential down-hole EM planned
- Other Juggernaut targets returned no economic intercepts in the maiden programme
Seymour drilling points towards an untested copper-gold centre
The most important result from Great Western Exploration’s (ASX:GTE) maiden drilling at the Juggernaut Copper-Gold Project is not a copper hit. It is the geological signature the company believes may sit around one: a zinc-silver-lead zone interpreted as the cooler outer margin of a volcanic-hosted massive sulphide system, with a hotter copper-gold core yet to be found.
The standout intersection was 12 metres at 0.33% zinc, 7.1 grams per tonne silver and 0.09% lead from 77 metres in hole 26GJGRC006. That interval included one metre at 1.02% zinc and two metres at 20.2 grams per tonne silver. Hole 26GJGRC002 returned five metres at 0.22% zinc, 2.1 grams per tonne silver and 0.15% lead from 97 metres. The reported lengths are downhole measurements, and true widths are not yet known.
Geology drives the VHMS interpretation
Great Western says the mineralised zones contain 1% to 5% sulphide minerals and sit at a shale-mafic volcanic contact, a setting it considers favourable for mound-style VHMS development. The zinc-silver-lead-sulphur signature, together with alteration in the host rocks, is being interpreted as evidence of a cooler, outboard position within a potentially fertile system.
The two holes are interpreted to have intersected the same folded stratigraphy, leaving the contact between them and areas to their north and south as priority targets. Juggernaut lies within the Yerrida Basin, about 70 kilometres south-east of Sandfire Resources’ (ASX:SFR) DeGrussa and Monty copper-gold VHMS deposits in the adjacent Bryah Basin. Great Western points to the comparable age and geological setting of the two basins, while acknowledging that VHMS exploration in the Yerrida has been limited.
Permitting and geophysics set the next test
The company is progressing permits for follow-up drilling and plans to combine the campaign with airborne infill magnetics and potentially down-hole electromagnetic surveys. Those programs are intended to refine the mineralisation model and sharpen drill targeting around the interpreted copper-core zones. The next phase therefore carries a more direct test of the thesis than the maiden holes: whether the peripheral zinc-silver mineralisation is connected to stronger copper and gold mineralisation nearby.
Results elsewhere in the programme were less compelling. Great Western said no economic intercepts were returned from the other Juggernaut targets, although it expects the planned geophysical work and geological modelling at Seymour may help reassess them. At the separate Baroo target, two shallow holes intersected the mapped quartz vein, returning one metre at 0.2% copper from 24 metres and one metre at 514 parts per million copper from 25 metres. Further drilling is planned there, with the company interpreting the vein as structurally controlled and suggesting its width and copper tenor may increase at depth.
Bottom Line?
Seymour has produced an encouraging geological vector, but the investment case now depends on whether follow-up drilling finds the copper-gold core the company has inferred rather than intersected.
Questions in the middle?
- Will follow-up drilling confirm copper and gold mineralisation between and around holes 26GJGRC002 and 006?
- What will the airborne magnetic and potential down-hole EM surveys add to the current VHMS model?
- Can Baroo’s narrow copper intersections develop into a wider or higher-grade zone at depth?
