Cosmo Metals has secured approval for up to 2,200 metres of maiden drilling at the Mona copper-gold-silver prospect in New South Wales. The campaign will test whether striking grades from historic mine dumps reflect concealed sulphide mineralisation below the old workings.
- Approval for up to eight drill holes and approximately 2,200 metres at Mona
- Historic mine dump samples returned up to 4.93% copper, 11.65g/t gold and 204g/t silver
- Drilling will target copper-rich VMS sulphides and a possible gold-silver feeder zone
- Mona sits within the 5km Everest-Mona-Victory trend and broader 20km Bingara VMS belt
- Downhole electromagnetic surveying is planned after the initial drilling campaign
Approval turns Mona’s surface clues into a drill test
Cosmo Metals Ltd (ASX:CMO) can now put its most compelling Bingara target to the test. The NSW Resources Regulator has approved up to eight drill holes totalling approximately 2,200 metres at Mona, the first drilling beneath the historic early-1900s workings.
The target is built around unusually strong but selective evidence. Fresh, sulphide-rich material collected from Mona’s mine dumps returned assays of up to 4.93% copper, 11.65 grams per tonne gold and 204 grams per tonne silver. Cosmo says geological mapping indicates the material may have come from the base of the old workings, where it could not be effectively processed by the original operators.
Drilling will test two overlapping mineralisation models
The initial holes are designed to cut the copper and zinc-bearing massive sulphide lode beneath and along strike of the historic mine. They will also extend into a potential feeder zone associated with the richer gold and silver results.
Cosmo interprets elevated molybdenum, bismuth and tellurium, together with cobalt depletion in the gold-rich samples, as evidence of a later intrusion-related overprint on the Mona volcanic-hosted massive sulphide system. That interpretation remains a geological model rather than a demonstrated deposit: no drilling has yet established the thickness, continuity or in-situ grade of the mineralisation.
The distinction matters. The reported grades come from grab samples of mine dump material selected to characterise mineralisation and alteration. Cosmo’s JORC disclosures state that the samples may not represent bulk grades at depth, and that no claim is made for continuity between samples. The drilling is therefore less a confirmation exercise than a test of whether the surface clues survive underground.
A first test in a much larger historic belt
Mona forms part of the 5km Everest-Mona-Victory trend at the southern end of the broader 20km Bingara VMS belt. The belt contains at least six recorded historic copper VMS mines, while Cosmo’s recent mapping, soil work, LiDAR and airborne magnetic surveys have identified the potential for concealed or stacked mineralised horizons.
Preparation is now moving through final documentation, local landholder engagement and drilling contractor discussions. Cosmo expects downhole electromagnetic surveying to follow the initial holes, with the aim of identifying lateral extensions of any massive sulphide bodies. That will give the campaign a second function: not just testing Mona, but potentially guiding the next round of drilling if conductors are identified.
The immediate catalyst is consequently straightforward but high-risk: mobilisation, followed by assays from the first holes. Until those results arrive, Mona’s headline numbers describe the quality of selected historical material, not a mineral resource. The central question is whether the old miners left behind an underground system large and continuous enough to justify Cosmo’s wider deposit-cluster theory.
Bottom Line?
Mona has moved from a compelling surface target to a defined drill program, but only drilling can show whether the spectacular dump grades have depth and continuity.
Questions in the middle?
- When will drilling contractors mobilise and when should the first assays be available?
- Will drilling intersect continuous copper-rich massive sulphides beneath the historic workings?
- Can downhole EM identify lateral extensions or additional concealed VMS bodies along the trend?