Great Northern Minerals has uncovered four undrilled chargeability anomalies at its Iron Butte Gold-Silver Project in Nevada, setting the stage for a maiden drilling campaign aimed at expanding the existing resource.
- Four undrilled DDIP chargeability anomalies identified
- Targets lie beneath and around existing inferred resource
- Potential for epithermal and Carlin-style mineralisation
- Drilling campaign planned for Q3 2026
- Permitting and contractor engagement underway
Four New Drill Targets Emerge from Reprocessed Geophysics
Great Northern Minerals Limited (ASX:GNM) has completed a detailed reprocessing of historical dipole-dipole induced polarisation (DDIP) geophysical data at its Iron Butte Gold-Silver Project in Nevada, revealing four compelling new undrilled chargeability anomalies. These targets span a 3-kilometre area and lie beneath or adjacent to the existing inferred resource, offering fresh opportunities to expand the deposit’s footprint.
The standout anomaly, dubbed Iron Butte Central, sits directly beneath the inferred silver resource and remains untested despite nearby drilling intersecting high-grade gold and silver mineralisation. Other anomalies; Iron Butte North, Iron Butte South, and Caetano; coincide with elevated gold and silver in surface soils, rock samples, or previous drill holes that ended in mineralisation, underscoring their potential.
Geophysical Insights Point to Sulphide Mineralisation
The chargeability anomalies detected by the DDIP survey are interpreted as zones of disseminated sulphides, which often correlate with epithermal and Carlin-style gold-silver mineralisation. The Iron Butte Central anomaly, with chargeability values up to 30 millivolts per volt, suggests a sulphide-rich zone beneath the oxide-dominated deposit. This is supported by a drill intercept of 1.5 metres at 13.5 g/t gold and 11.5 g/t silver near the anomaly’s edge, hinting at the potential for significant mineralisation at depth.
Similarly, the Iron Butte North anomaly aligns with a strong geochemical gold-silver soil anomaly, while the Iron Butte South target lies beneath drill holes that ended in mineralisation, including 51.8 metres at 0.2 g/t gold and notable silver grades. The Caetano anomaly, located on newly staked claims, also rests near previous drilling with elevated gold and silver assays.
Upcoming Maiden Drilling Campaign to Test Targets
Great Northern Minerals is advancing permitting and contractor engagement to commence its maiden drilling campaign in the third quarter of calendar year 2026. This program aims to test the four newly defined DDIP targets with the goal of expanding the current JORC Mineral Resource Estimate, which was recently reported at 480,000 ounces of gold and 11.5 million ounces of silver. The drilling will focus on extending mineralisation along strike and at depth, particularly targeting the potential for Carlin-style deposits beneath the existing resource.
The company is also integrating ongoing drone magnetic survey data to refine drill target prioritisation further. Non-Executive Chairman Eddie King highlighted the significance of these targets, noting their potential to substantially increase the scale and upside of Iron Butte within the prolific Battle Mountain-Cortez mining district.
Exploration Context and Technical Rigor
The Iron Butte project has a rich exploration history, with over 146 reverse circulation and two diamond drill holes completed by major companies including Chevron, Newmont, and Newcrest between 1980 and 2022. The recent geophysical reinterpretation by Resource Potentials, combined with historical drilling and geochemical data, provides a robust foundation for the upcoming exploration phase.
Assay data from previous drilling employed industry-standard fire assay and aqua regia methods, with quality control procedures confirming data reliability. However, true widths of mineralisation remain unknown pending further structural work and drilling, a common challenge in early-stage exploration of complex epithermal and Carlin-style systems.
Bottom Line?
The identification of four undrilled chargeability anomalies at Iron Butte sharpens Great Northern Minerals’ exploration focus ahead of its maiden drill campaign, but the true extent and grade of mineralisation beneath remain to be proven.
Questions in the middle?
- Will the maiden drilling confirm high-grade mineralisation beneath the central anomaly?
- How will ongoing drone magnetic data influence final drill target selection?
- What is the potential scale of Carlin-style mineralisation at depth beyond current resource boundaries?