PROJECTs • Exploration projects
Oso Negro, Sonora
20.3g/t
Au - Highest Phase II Rock Chip
3,480 g/t
Ag highest Phase II rock chip assay
>3 km
km mapped vein strike
~2,5000m
planned maiden diamond drilling
Overview
Oso Negro is an undrilled low sulphidation epithermal gold-silver vein system in the northern Sonora epithermal belt. Mapping and sampling in 2026 extended the system to more than 3 kilometres of vein strike across the Prospecto and Tere structures. The veins are up to 3 metres wide and multiphase, with common breccias and pervasive iron oxides after sulphides. The property is held under an option to acquire a 100% interest from Heliostar Metals and sits entirely on private land.
Surface sampling
Two rock chip programs collected 510 samples. Phase One, reported June 9, 2026, returned assays up to 14.8 g/t gold and 2,340 g/t silver from 156 samples. Phase Two, reported September 10, 2026, returned assays up to 20.3 g/t gold and 3,480 g/t silver from a further 354 samples. In Phase Two, 63 samples returned between 1 and 20.3 g/t gold and 58 returned between 100 and 3,480 g/t silver. The Prospecto vein and its southeast splays are gold and silver mineralized along their full 600 metre mapped strike.
Maiden drill program
We have received the drill permit from SEMARNAT and finalized a 2,500 metre diamond program from 20 drill pads across Prospecto and Tere. Pads are designed for several holes each, which keeps pad building and rig moves down. The holes are shallow and angled, set to cut the veins 40 to 80 vertical metres below outcrop samples that returned high gold and silver grades. The first question the program has to answer is whether those surface grades hold at depth.
Why depth matters
Vein textures logged in mapping are typical of the upper levels of a low sulphidation epithermal system. In systems like this the highest precious metal grades are commonly found in a boiling zone at depth. At Oso Negro that zone has not been tested.
Permitting and access
The drill permit has been granted for the Oso Negro concession. We signed a surface access agreement with the private landowner on August 28, 2026, for an initial one-year term that can be renewed.
Cautionary Note
Rock chip samples are selective by nature and may not be representative of the grade of the mineralization. Sampled widths are not true widths. Surface sampling results are not indicative of results that may be obtained from drilling. Planned drill hole traces are preliminary and subject to final program design and ground conditions. Oso Negro is an undrilled property and no mineral resource has been estimated.
project
Company | Market Cap. | Project Name and Location | Resources and Reserves |
|---|---|---|---|
Rio Tinto | n/a
| Jadar, Serbia
| 85.4 Mt @ 1.76% LiO2 and 16.1% B2O3 (Ind.); 58.1 Mt @ 1.87% Li2O and 12.0% B2O3 (Inf.)¹. |
Ioneer Ltd. | AUD 510 million (12 month high of AUD 925 million)
| Rhyolite Ridge, CA
| 146.5 Mt @ 0.35 % LiO2 and 4.56 % B2O3 (M+I+I)².
|
5e Advanced Materials Inc. | AUD 214 million (12 month high of AUD 969 million) | Fort Cady, CA | 74.3 Mt @ 0.076 % LiO2 and 4.15% B2O3 (M+I); 96.9 Mt @ 0.069 % LiO2 and 4.75% B2O3 (Inf.)³. |
¹ Rio Tinto updates Ore Reserves and Mineral Resources at Jadar, Notice to ASX, 23 February 2022.
² IONEER USA Corp. Rhyolite Ridge Lithium-Boron Project Definitive Feasibility Study (DFS) Report (Li2CO3 and H3BO3 values converted to LiO2 and B2O3).
³ 5e Advanced Materials Inc., Form 8-K, May 11, 2023. Commission File Number 001-41279