Great Northern Minerals (ASX:GNM) flies drone magnetics as the Q3 drill clock starts

The survey now feeds straight into target selection for a maiden program chasing Carlin-style upside beneath 480,000oz.

Great Northern Minerals (ASX:GNM) has wrapped up a high-resolution drone magnetic survey over its Iron Butte gold-silver project in Lander County, Nevada. The survey covers the central resource area plus the newly staked Caetano Rim ground to the north, and it now feeds directly into target selection for the maiden drilling program planned for Q3 CY2026.

On the surface this looks like a routine technical update. We think it is more than that. Iron Butte only landed its maiden 480,000oz gold and 11.5Moz silver resource on 12 June, and the company is already moving to the next step in the sequence rather than sitting on the headline number.

The survey flew at 25 metres above ground level, which is low enough to pick out subsurface faults, lithological contacts and structural corridors that a conventional airborne survey would smear over. In orogenic and Carlin-style systems, those structures are exactly where the gold tends to sit. The data now goes into a geophysical reinterpretation that pulls in the historical datasets as well.

For investors, the question is whether all this target generation actually converts into drill hits in a few months time. That is the bar GNM has set itself.

Why a drone magnetic survey is doing real work, not just optics

Magnetic surveys map bedrock geology beneath cover by reading the magnetic differences between rock types. In plain English, the drone gives the geologists an X-ray of what is under the dirt without needing to drill it first.

At Iron Butte the mineralisation sits in a setting where faults, shear zones and lithological contacts control where gold concentrates. Finding those features cheaply is what makes the difference between a scattergun drill program and a focused one.

The 25-metre flight height matters here. Tight line spacing and low altitude give a resolution that historical regional surveys simply did not have, which is why this dataset can actually move drill collars rather than just confirm what was already known.

The Caetano Rim addition quietly doubles the footprint in play

The survey did not just cover the original 24 claims around the central resource. It also covered the 35 additional claims at Caetano Rim that GNM staked in May 2026, taking the project footprint to 59 claims.

That matters because the maiden resource only sits across the original central zone. The Iron Butte North and East soil anomalies that GNM walked in April, which returned rock chips up to 8.3 g/t gold at surface, sit in the broader footprint that is now being imaged for the first time at this resolution.

If the magnetics light up structural corridors linking the central resource to those untested anomalies, the bulk-tonnage story we have written about previously stops being a single-deposit story.

The Carlin-style target underneath is the real prize

The maiden resource is an oxide heap-leach story sitting in the same grade window as Marigold, Florida Canyon and Phoenix. That alone gives GNM a peer set and a plausible exit conversation.

The bigger prize is the deeper system. One historical hole returned 1.5m at 13.5 g/t gold from 405m, well below the current resource shell, and only two holes have ever tested that depth. The magnetics are being explicitly tasked with helping define drill targets beneath the existing MRE.

Carlin-style ounces in Nevada are typically higher grade and more valuable per ounce than oxide ounces. Our concern is that depth drilling burns cash fast, and the company had A$3.9 million on hand at the time of the maiden resource. The next funding update is the one to watch.

The Investors Takeaway for Great Northern Minerals

GNM has now done the resource, the soil sampling, the new claim staking and the drone magnetics in roughly two months. Drill planning and permitting are running in parallel, and surface sampling results from Caetano Rim are due in late July. The pace is genuine, and it is being directed at a single decisive event in the September quarter.

Our view is that the maiden drilling program is the real value inflection point, not this survey on its own. Investors should be watching three things over the next three to four months. The surface sampling results in late July, the permitting timeline holding into Q3, and any update on funding the depth-focused holes that test the Carlin thesis.

Readers can see our prior coverage of the maiden resource and the broader Iron Butte thesis at stocksdownunder.