With strong momentum behind it, Nova Minerals Ltd (ASX:NVA, NASDAQ:NVA, OTC:NVAAF) has ramped up its 2025 drilling campaign at the RPM deposit within the Estelle Gold and Critical Minerals Project in Alaska. The program now includes two diamond rigs and one reverse circulation (RC) rig operating around the clock.
The company has its eye on completing several key objectives, including expanding and connecting the RPM North and RPM Valley zones, assessing near-surface mineralised material within the valley fill, and advancing a maiden drill program at the Stibium antimony-gold prospect.
Initial geological observations have been promising, and the company expects assay results in the coming months.
Nova is also undertaking additional activities which include resource definition drilling at Korbel, environmental and technical studies for the Pre-Feasibility Study (PFS), and continued engagement with the United States Department of Defense for potential grant funding related to the antimony project.
“We are excited to be back at RPM this season, advancing our efforts to grow and upgrade the Valley zone resource to the west, while also testing a compelling conceptual target to the east that could significantly expand the RPM footprint,” Nova Minerals exploration manager, Hans Hoffman said.
“The first drillhole into the RPM Valley zone has already delivered some of the most promising sulfide mineralisation and quartz veining observed at RPM to date. Encouragingly, it has also extended our understanding of the mineralised intrusive body further north within the Valley zone. We are optimistic that the intrusive/hornfels contact intersected may represent an extension or offset of the high-grade RPM North zone located on the ridge above.”
Resource expansion underway at RPM
Diamond drilling is focused on extending mineralisation east and west of the RPM North zone, aiming to connect with the RPM Valley zone. A separate rig has been mobilised to RPM Valley, where initial drillholes have returned highly encouraging geological observations, including visible quartz veining and sulphide mineralisation.
These findings suggest potential extensions of the known intrusive body and raise the possibility of linking the high-grade ridge-hosted RPM North deposit with the valley targets below. This area remains underexplored, and early interpretations point to a potentially larger mineralised footprint than previously estimated. Drill data will be used to support future resource upgrades.
RC rig confirms near-surface potential
The RC rig has demonstrated the ability to efficiently drill through glacial till, penetrating 30 metres within a few hours. This method is proving effective for testing the valley-fill material believed to originate from the erosion of RPM North.
Previous surface sampling across the valley identified a greater-than-1 gram per tonne (g/t) gold-in-soil anomaly over 1.7 kilometres, with estimated mineralised thicknesses nearing 40 metres. This provides significant near-surface gold resource upside and represents a cost-effective exploration path. Samples from this phase are expected to further define the scale of this secondary mineralisation.
“Our RC drilling program is also performing well, rapidly penetrating glacial till and confirming its effectiveness in testing the mineralised valley-fill material derived from RPM North. This material, averaging over 1g/t gold across surface samples, extends for approximately 1.7 kilometres with estimated thickness nearly 40 meters — offering substantial potential for near-surface resource upside,” Hoffman said.
“Drilling activities at RPM are progressing at full pace, and we look forward to receiving assay results in the near term.”
Maiden drilling program at Stibium prospect
A third rig is continuing the maiden drilling at the Stibium prospect, targeting antimony-gold mineralisation.
Early-stage drilling has intercepted near-surface mineralisation, supporting geological modelling based on outcropping stibnite veins and high-grade soil geochemistry.
The program aims to assess the extent and continuity of these structures, with a view to defining a resource in support of future antimony supply initiatives. This aligns with Nova’s broader strategy to develop Estelle into a critical minerals hub.
Additional activities support PFS
In parallel with drilling, Nova is progressing multiple supporting initiatives for the ongoing Pre-Feasibility Study. Closed-spaced RC drilling at the Korbel starter pit area has been completed, with samples to be dispatched to laboratories. Environmental baseline work, geological mapping, road access development, and other technical investigations are underway across the Estelle Project.
These programs are designed to de-risk development and underpin future mine planning.
US defence grant discussions continue
Nova is also actively advancing discussions with the United States Department of Defense regarding potential funding for the development of its antimony assets. The company anticipates a decision on the grant in the near term.
This initiative reflects growing US interest in securing domestic sources of critical minerals, with Estelle positioned to play a strategic role in future antimony supply chains.