Black Bear Minerals Ltd
Black Bear Minerals Drills High-Grade Silver Outside Shafter Resource Boundary
Black Bear Minerals (ASX: BKB) has reported further high-grade silver results from its 2025 to 2026 diamond drill program at the Shafter Silver Project in Texas, with one intercept positioned outside the current foreign Mineral Resource Estimate (MRE). According to the ASX announcement, the latest assays include up to 1,333 g/t silver over 0.5m, while twin-hole drilling continues to return wider and higher-grade mineralisation than the historic holes it was designed to test.
For investors, the update matters for two reasons. First, the drilling appears to support the continuity of silver mineralisation beyond the current resource boundary. Second, the validation programme is testing whether the historic drilling dataset that supports Shafter's 17.57 million ounce silver foreign MRE may understate grade and thickness.
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The Latest Shafter Drill Results
The current update covers assay results from SFD020, SFD022 and SFD023. Each hole adds a different layer to the geological picture at Shafter.
| Hole ID | Intercept | Silver grade | From | Notable higher-grade interval |
|---|---|---|---|---|
| SFD020 | 11.9m | 148 g/t Ag | 78.9m | 0.5m @ 1,333 g/t Ag |
| SFD022 | 3.8m | 171 g/t Ag | 146.2m | 1.1m @ 328 g/t Ag |
| SFD023 | 2.8m | 116 g/t Ag | 106.9m to bottom-of-hole | 0.5m @ 444 g/t Ag |
According to the announcement, SFD020 also returned 0.1% lead, 0.4% zinc and 0.1 g/t gold within the broader mineralised interval, while SFD022 returned 0.2% lead, 0.6% zinc and 0.1 g/t gold. In SFD023, the bottom-of-hole interval included 2.6% lead.
The end-of-hole result in SFD023 is important because it suggests the mineralised zone may continue below the depth drilled. In practical terms, the hole did not fully close off the zone, leaving room for follow-up drilling.
What Did the CEO Say?
"The latest drilling has delivered another strong set of high-grade silver results at Shafter," said Dennis Lindgren, Chief Executive Officer of Black Bear Minerals.
"The results are significant because they validate known high-grade zones and support potential extensions outside the current foreign MRE, with the twin holes returning thicker and higher-grade intervals than the comparable historic drilling as we progress resource validation, JORC conversion and restart study work."
Twin-Hole Drilling Is Returning Stronger Results Than Historic Holes
A central part of Black Bear's current work at Shafter is its twin-hole programme. A twin hole is a new drillhole placed close to a historic hole to test whether older results can be repeated using modern drilling, sampling and laboratory methods.
In this update, SFD020 and SFD022 were drilled to twin historic holes from the 1940s and 1980s. The comparison is drawing market attention because the modern holes have returned thicker and higher-grade intercepts.
| BKB hole | BKB result | Historic hole | Historic result |
|---|---|---|---|
| SFD020 | 11.9m @ 148 g/t Ag | SD183 | 5.8m @ 109 g/t Ag |
| SFD022 | 3.8m @ 171 g/t Ag | AMAX1261 | 0.9m @ 157 g/t Ag |
The company stated that all twin drillholes completed by Black Bear to date have returned higher-grade and thicker mineralised intervals than the corresponding historic holes. That does not make the datasets directly equivalent, and the company cautioned that differences in sampling, analytical methods and record keeping mean comparisons should be treated carefully.
Even so, the pattern is relevant because much of the foreign MRE relies on older drilling with limited documented quality assurance and quality control. Historic AMAX drilling, in particular, was often selectively sampled based on visible geology, leaving some intervals unsampled.
The ASX release also noted that older silver assays generally used a two-acid digest method, which may be less complete than the modern four-acid digestion or other current analytical approaches. That is why Black Bear has started check analyses on twinned holes, with results expected in around four to six weeks from the announcement date.
Why SFD022 May Be the Most Important Hole in This Update
While the highest silver assay came from SFD020, the most strategically relevant hole may be SFD022. According to the announcement, this intercept sits outside the current foreign MRE boundary and is located about 100m along strike east of AMAX1260, a historic underground hole that returned very high-grade silver:
- AMAX1260: 8.2m @ 590 g/t Ag, including 3.4m @ 1,164 g/t Ag
No drilling has yet been completed between SFD022 and AMAX1260 to fully test the modelled mineralised horizon in that area. This gap matters because positive results between the two holes could support expansion of the current resource footprint.
Furthermore, the company noted that the SFD022 intercept aligns well with mineralisation seen in nearby holes at the base of the Cretaceous-Permian unconformity. In simpler terms, the silver appears to sit at a consistent geological boundary between rock units, giving more confidence that the zone continues along strike rather than occurring as an isolated lens.
For investors, that consistency is important. Deposits that follow a predictable geological horizon are generally easier to model and may offer better scope for resource growth through step-out drilling.
Understanding Manto-Style Silver Mineralisation
Shafter's silver system is described in the announcement as manto-style carbonate replacement mineralisation hosted in the Mina Grande Formation. This is specialist geological language, but the basic concept is straightforward.
A manto is a relatively flat, sheet-like ore body. It forms when metal-bearing fluids move through favourable layers in carbonate rocks such as limestone and replace part of that rock with silver-bearing and base metal minerals.
At Shafter, drilling indicates that mineralisation has formed a shallowly dipping, continuous tabular body near the upper contact of the Mina Grande Formation, close to an unconformity with younger Cretaceous rocks. An unconformity is simply a boundary between rock sequences of different ages, and it can act as a pathway or trap for mineralising fluids.
Why Does the Geometry Matter to Investors?
- Geometry matters for mining: Flat, continuous zones can be easier to trace and may support more predictable mine planning.
- Continuity supports resource growth: If one hole finds mineralisation on a known horizon, there is a geological basis to test along strike and at depth.
- Shallow dips can help development studies: The shape of the ore body influences mining method, costs and the layout of a potential restart.
This does not guarantee economic extraction. However, understanding the geometry of the mineralisation helps explain why step-out drilling outside the current MRE can have meaningful upside.
Polymetallic Potential Is Becoming a Bigger Part of the Shafter Story
The Shafter foreign MRE currently includes silver only. Yet Black Bear's recent work indicates that the project also hosts zinc, lead, gold and possibly vanadium, none of which have been incorporated into the current resource model.
The strongest polymetallic result referenced in the update came from SFD024, previously released on 4 June 2026:
- 10.7m @ 3.3% zinc from 122.3m
- Including 1.7m @ 19.8% zinc, 1.0% lead and 0.3 g/t gold
- Peak interval of 36.5% zinc, 0.5 g/t gold, 2.1% lead and 30 g/t silver over 0.6m
A separate historical and current drilling pattern suggests the higher-grade zinc-lead mineralisation is concentrated near the MacDaniel Structural Corridor, a northeast-trending fault system also linked to silver mineralisation. That spatial relationship may matter in future technical studies.
In addition, the company said it plans to:
- Re-log and sample available historic core
- Assess the extent of polymetallic mineralisation outside the foreign MRE
- Undertake metallurgical testwork to evaluate possible gold, zinc and lead by-product contributions
- Incorporate multi-commodity data into a future JORC estimate, if supported by results
Recent rock chip sampling outside the current resource area has also returned up to 3,100 g/t Ag, 4.5% zinc and 6% lead, according to earlier company announcements referenced in the release.
The Current Foreign MRE and the Path to JORC Conversion
Black Bear first announced the Shafter foreign MRE on 2 October 2025. It was prepared under Canadian NI 43-101 standards and is not yet reported in accordance with the JORC Code 2012, which is the Australian reporting standard required for ASX resource disclosure.
The current foreign estimate stands at:
| Classification | Cut-off | Tonnes | Grade | Contained silver |
|---|---|---|---|---|
| Measured | 137 g/t Ag | 0.09 Mt | 299 g/t Ag | 0.89 Moz |
| Indicated | 137 g/t Ag | 1.01 Mt | 314 g/t Ag | 10.17 Moz |
| Inferred | 137 g/t Ag | 0.79 Mt | 256 g/t Ag | 6.51 Moz |
| Total | 137 g/t Ag | 1.89 Mt | 289 g/t Ag | 17.57 Moz |
The company stated clearly that a competent person has not yet done sufficient work to classify this foreign estimate as a JORC Mineral Resource. Until that work is completed, there is no assurance the estimate will be reported under JORC.
That is where the validation drilling becomes central to the investment case. By twinning older holes, infilling selected areas and reviewing historical analytical methods, Black Bear is working toward a maiden JORC-compliant resource estimate.
If the newer drilling continues to support stronger mineralised widths and grades than the legacy dataset, the future JORC model could differ materially from the current foreign estimate. However, that outcome remains subject to further work.
Next Steps Investors Are Likely to Watch
The ASX update outlined a sequence of near-term activities at Shafter.
1. Check Analyses of Twin Holes
These are expected within four to six weeks and may help determine whether historic silver assays under-represent grade.
2. Limited Infill Drilling for JORC Validation
The company plans further drilling to support conversion of the foreign MRE into a maiden JORC estimate.
3. Rapid Mine Restart Study Work
Black Bear said it is progressing technical and restart studies as part of a potential restart pathway.
4. Additional Drilling Outside the MRE
Future holes are planned across the project area, including testing for extensions beyond the current resource boundary.
5. Sampling of Historic Presidio Workings
The company said 1km of strike in historic mine workings remains excluded from the foreign MRE and requires systematic sampling. Historically, selective mining targeted ore above 500 g/t Ag, meaning lower-grade material may remain in the walls of stopes and drifts.
6. Ongoing Polymetallic Studies
Historic core re-logging, sampling and metallurgy are planned to assess whether zinc, lead and gold can be incorporated into future resource work.
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Why Shafter Is Drawing Attention
Shafter is an advanced silver asset with substantial historic production and existing site infrastructure. According to the company, the historic Presidio Mine produced 35.2 million ounces of silver between 1883 and 1942 at an average grade of 521 g/t Ag.
The site also includes a permitted Merrill-Crowe processing plant, grid-connected power, water rights and more than 160km of historic underground workings.
The latest drilling update does not change the status of the current foreign MRE, nor does it settle the outcome of JORC conversion work. What it does provide, however, is further evidence that the silver system at Shafter may extend beyond the present model and that modern drilling is returning stronger results than some of the historical holes.
For investors following ASX silver stocks, the next value drivers are becoming clearer: check assay results, JORC conversion progress, extension drilling outside the MRE, and whether polymetallic credits can be formally incorporated into the project model. If those workstreams continue to deliver supportive data, Shafter may attract increasing attention as a high-grade US silver development story with genuine restart potential.
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