Terra Uranium uncovers high-grade silver at Castle Rag, NSW

Key highlights

• Rock chips up to 941 g/t silver at the Castle Rag Mine, with 18.9% lead and 266 g/t antimony in the same sample; copper up to 2.21% recorded 500 m to the north at Matt & Walkers. 
• 14 of 23 historical surface samples (2022) exceed 100 g/t Ag across Castle Rag, Matt & Walkers, and Gilligan’s. 
• Builds on prior intercepts including 1,670 g/t Ag, and silver-with-base-metals hits (e.g., 445 g/t Ag + 1.12% Cu). 
• Castle Rag is cited as analogous to the Webbs Silver Deposit, with larger historic production (~4,000 t mined for 48 t Ag and 692 t Pb).
• Work program: dataset review, LiDAR/open-file geophysics, remote sensing, access, then a two-year field program focused on in-fill and depth extensions. 
  
   

Terra Uranium (ASX: T92) has reported new high-grade silver results from historical surface sampling at its 100%-owned Castle Rag project in New South Wales, strengthening the narrative that this corner of the New England region hosts not just uranium potential but multi-commodity critical-metals opportunities. While the headline is silver, associated lead, antimony and copper point to a broader polymetallic system that merits systematic follow-up. 

What the assays show

The company compiled 23 rock-chip assays collected in 2022 by previous operators across three prospects—Castle Rag Mine, Matt & Walkers (~500 m north), and Gilligan’s (~1.2 km northeast). Fourteen samples return >100 g/t Ag, led by R00535 at Castle Rag (941 g/t Ag, 18.9% Pb, 266 g/t Sb, 2.45% Zn) and R00537 at Matt & Walkers (723 g/t Ag, 2.21% Cu). These are grab samples from surface outcrop/float (~3 kg each), collected for orientation and prospectivity purposes. 

In isolation, rock chips are not resource statements—they do, however, vector exploration toward shoots, pipes, or lodes that may host grade and width at depth. Terra’s dataset also references earlier Castle Rag drill intercepts reported in March 2025, including 1,670 g/t Ag, 445 g/t Ag with 1.12% Cu, 210 g/t Ag with 1.19% Cu/1.19% Pb/0.41% Zn, and 120 g/t Ag with 5.25% Pb/0.6% Zn/0.418% Sn—a pattern consistent with silver-lead-zinc-copper systems of the district. 

Geological context: a Webbs-style analogue with bigger historic output

Terra notes Castle Rag has been likened to the Webbs Silver Deposit—one of NSW’s better-known high-grade silver systems—but with substantially larger recorded historic production: ~4,000 tonnes mined for 48 tonnes of silver and 692 tonnes of lead, versus Webbs’ ~5.5 tonnes of silver historically recorded. While analogues are not destiny, this framing explains the company’s emphasis on structural targets and east-plunging pipe or shoot geometries under evaluation. 

The project sits within Terra’s New England portfolio, which also includes the Ottery Tin Mine, Mole River base-metals project, and Glen Eden—host to NSW’s largest tungsten deposit. Collectively, that footprint gives T92 options across the critical-metals spectrum, a sensible hedge in a market where silver, tin, tungsten, copper and antimony cycle differently through technology and industrial demand. 

How the data were generated (and why that matters)

The 2022 rock-chip program—run by Great Southern Precious Metals under the prior licence—was assayed by ALS Global using Au-AA26 (fire assay for gold), ME-ICP61 (four-acid digest), and OG62 (ore-grade four-acid digest) where needed for high base-metal values. Samples were surveyed in GDA94 / Zone 56, with lab standards and blanks applied according to ALS protocols. Terra’s Competent Person reviewed the original assay sheets and NSW DIGS submissions and considers the work JORC 2012-compliant for reporting historical results. Notably, no drilling accompanied the 2022 chips; the company therefore treats them as orientation data, not as basis for estimation. 

That distinction is core to valuation. Surface grabs can over- or under-state the true tenor depending on exposure and weathering; however, they do confirm metal presence and can refine targeting for drilling. Terra’s decision to package the 2022 results alongside recent intercepts is therefore less about declaring size today and more about building a coherent geochemical-structural model to guide systematic work. 

Management and governance signals

Today’s release is authorised by Chairman Andrew J. Vigar, who also serves as Competent Person for the historical data review under JORC 2012. While T92 did not include direct executive quotes in this announcement, the document’s emphasis is unmistakable: consolidate the silver story at Castle Rag, roll up legacy datasets into an integrated model, and move toward drill-ready targets spanning near-surface high-grade zones and potential down-plunge extensions. That read-through dovetails with the company’s broader critical-metals build-out in NSW. 

Next steps: de-risking toward drills

Terra outlines a phased program: (1) comprehensive literature and dataset review, including LiDAR and open-file geophysics, (2) remote-sensing to prioritise structures, and (3) obtaining land-access approvals ahead of ground work. The company then plans a two-year exploration program focusing on in-fill to define mineable higher-grade zones and testing at depth for continuity—exactly the work sequence needed to convert rock-chip promise into drill-defined potential. Timing will hinge on access and permitting, but the workplan suggests disciplined sequencing rather than rush-to-drill optics. 

Balanced view: upside and risks

• Prospectivity: Rock chips up to 941 g/t Ag and prior 1,670 g/t Ag intercepts are encouraging and justify methodical follow-up. The polymetallic signature (Pb, Sb, Cu, Zn, Sn) broadens potential revenue streams if width and continuity are demonstrated. 
• Workplan quality: The emphasis on data-led targeting (LiDAR/geophysics/remote sensing) and access sequencing is a positive governance signal for an early-stage program. 
• Key risks: Rock chips are non-representative by nature; no drilling accompanies the 2022 dataset. Structural complexity can localise grade into narrow shoots, limiting bulk potential. Permitting/access may pace the timetable. And as with any small cap, funding cadence and market volatility can influence program speed. 
  
   

Bottom line: Today’s update improves the geological case for Castle Rag as a high-grade silver system with polymetallic credits inside a district-scale NSW portfolio. The next catalyst set is target definition and drilling—the only reliable arbiter of grade-times-width continuity the market will pay for. 

At the time of writing this article, T92 traded at A$0.073 (+12.31%), with volume near 3.95 million shares.