Aldebaran Resources Inc. (TSX-V: ALDE, OTCQX: ADBRF) and Centauri Minerals Inc. are pleased to announce the results of an updated mineral resource estimate for the Rio Grande gold-copper project in Salta, Argentina.
Highlights
Sam Leung, Chief Executive Officer and Director of Centauri, commented: “This new mineral resource estimate is fresh evidence that encourages modern exploration and future studies on the Rio Grande gold-copper project. With no drilling or targeting programs since 2012, Centauri now has the exciting opportunity to apply modern geophysical and geochemical tools ahead of future drilling programs on a project that already contains a substantial mineral inventory. With this resource in hand, a drill program planned for later this year and five additional exploration projects in our portfolio, Centauri is well set up to move forward to becoming a public company in the first half of 2026.”
Dr. Kevin B. Heather, Chief Geological Officer of Aldebaran Resources and Technical Advisor to Centauri, commented: “I have been directly involved in the exploration at the Rio Grande gold-copper project since 2004 and we have always felt the project needed additional exploration to realize its full potential. The MRE reported here marks a significant milestone in the resurrection of the project, and I look forward to working with the Centauri team to unlock significant value in the future.”
Mineral Resource Estimate
SLR Consulting (Canada) Ltd. was retained by Centauri to complete a National Instrument 43-101 Technical Report and Mineral Resource Estimate update for the Rio Grande gold-copper project, located in Salta Province, Argentina. The Rio Grande gold-copper property is located in the Altiplano of northwest Argentina and supported by established infrastructure that services regional mines. The property ranges in elevation between 3,700 m and 4,700 m above sea level and is located approximately 260 km west of the city of Salta, 40 km east of the Chilean border, and 9 km from the operating Lindero gold-copper mine. SLR visited the Rio Grande property from December 5 to 7, 2025.
To generate a new resource pit shell, SLR applied new Whittle input parameters to the 2018 resource block model from the NI 43-101 Technical Report and MRE completed by Roscoe Postle Associates Inc. (since acquired by SLR in 2019) and dated August 17, 2018. There has been no new drilling or trenching work carried out at Rio Grande since 2013.
RPA used Datamine Studio RM and Leapfrog Geo software to build the resource block model. The resource database contains drilling and trenching data to the end of November 2012. The database is comprised of 124 drill holes for a total of 74,201 m of drilling and 84 trenches with a total length of 9,489 m. Both drill holes and trenches were used for resource estimation. Wireframes for geology and mineralization were constructed in Leapfrog Geo based on geology sections, assay results, and lithological information. Assays were capped to various levels based on exploratory data analysis and then composited to four metre lengths.
Wireframes were filled with blocks measuring 10 m by 10 m by 10 m with sub-celling at wireframe boundaries. Blocks were interpolated with grade using Ordinary Kriging. Block estimates were validated using industry-standard validation techniques. Classification of blocks was based on distance criteria. Definitions for resource categories are consistent with CIM (2014) definitions as incorporated into NI 43-101. Blocks were classified as Indicated and Inferred based on the following criteria:
The Rio Grande project is situated next to the operating Lindero Au-Cu mine (Figure 1) and it includes five Mineral Resource areas, ranked by relative contribution: Discovery–Sofía, Central (West and East), North, Southwest, and Seven (Figure 2).
The conceptual processing strategy for Rio Grande includes Heap Leach with SART for oxide material, a combined Heap Leach–SART and flotation approach for transitional material, and flotation for sulphide material. While several viable gold and copper recovery options have been evaluated, the final process flowsheet has not yet been defined and will require additional metallurgical test work. Each process assumes different recoveries for gold, copper, and silver. The updated MRE for Rio Grande is provided in Table 1. A supporting NI 43-101 Technical Report will be filed on SEDAR at www.sedarplus.com within 45 days.
Table 1: Rio Grande Open Pit Mineral Resource Estimate – February 15, 2026
| Category | Oxidation | Tonnes (Mt) |
Au (g/t) |
Cu (%) |
Ag (g/t) |
Au (koz) |
Cu (kt) |
Ag (Moz) |
| Indicated | Oxide | 94.1 | 0.26 | 0.20 | 2.1 | 781 | 188 | 6.3 |
| Transitional | 47.3 | 0.34 | 0.33 | 3.6 | 523 | 156 | 5.5 | |
| Sulphide | 12.3 | 0.36 | 0.29 | 2.3 | 144 | 36 | 0.9 | |
| Indicated | 153.7 | 0.29 | 0.25 | 2.6 | 1,448 | 384 | 12.7 | |
| Inferred | Oxide | 144.5 | 0.19 | 0.16 | 2.2 | 898 | 231 | 10.3 |
| Transitional | 75.6 | 0.26 | 0.24 | 3.0 | 643 | 181 | 7.4 | |
| Sulphide | 0.7 | 0.25 | 0.24 | 4.1 | 6 | 2 | 0.1 | |
| Inferred | 220.8 | 0.22 | 0.19 | 2.5 | 1,547 | 420 | 17.8 | |
| Notes:
1) CIM (2014) definitions were followed for Mineral Resources. |
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Exploration Potential
Mineralization at Rio Grande remains open at depth in all of the known zones, particularly in the Sofia and Southwest zones. Drilling completed to date has primarily tested the upper portions of the mineralized system, however many of the existing drill holes terminated in sulphide mineralization. In addition, geological interpretation indicates potential for deeper sulphide extensions of the known zones, with historic drilling intercepting mineralization in porphyry dykes whose source has yet to be discovered. This potential is conceptual in nature, and insufficient drilling has been completed to define additional Mineral Resources; however, the observed continuity of alteration and structural controls supports continued exploration.
Centauri Next Steps
Centauri is currently working on the legal and commercial requirements to complete the previously announced spinout and go-public event, expected to be completed in the first half of 2026. In addition, Centauri is building out a management and exploration team to advance the exploration portfolio, including developing new drill targets for the Rio Grande project with the intention to commence a drill program on the project in 2026.
Value to Aldebaran Shareholders
Aldebaran and Centauri have executed a definitive share transfer agreement pursuant to which Centauri will acquire all of the shares of Aldebaran Argentina S.A. and Minera El Toro S.A., the Aldebaran subsidiaries that hold the Rio Grande, Aguas Calientes, and four other early-stage mineral exploration properties in Argentina. In exchange, Aldebaran will receive 40,000,000 common shares (representing approximately 78% of the currently outstanding Centauri shares, with the balance owned by investors in the recent placement by Centauri. The share transfer is subject to certain conditions, and closing is expected to occur in the first quarter of 2026 (see Company news release dated October 24, 2025). Aldebaran intends to distribute shares of Centauri to Aldebaran shareholders upon a go-public event for Centauri. Aldebaran may elect to distribute the Centauri shares all at once or in stages and may retain a minority interest in Centauri. The formation of Centauri allows Aldebaran shareholders to maintain their exposure to the Altar copper-gold project in San Juan, Argentina, while also receiving additional value from the other properties currently owned by Aldebaran through the shares in Centauri that they will ultimately receive.
For further information or to subscribe to the Centauri news list, please contact:
Sam Leung
CEO and Director
Centauri Minerals Inc.
Phone: +1 416 206 4187
Email: sam.leung@centauriminerals.com
Ben Cherrington
Manager, Investor Relations
Aldebaran Resources Inc.
Phone: +1 347 394-2728 or +44 7538 244 208
Email: ben.cherrington@aldebaranresources.com
About Aldebaran Resources Inc.
Aldebaran is a mineral exploration company that was spun out of Regulus Resources Inc. in 2018 and has the same core management team. Aldebaran holds an 80% interest in the Altar copper-gold project in San Juan Province, Argentina. The Altar project hosts multiple porphyry copper-gold deposits with potential for additional discoveries. Altar forms part of a cluster of world-class porphyry copper deposits which includes Los Pelambres (Antofagasta Minerals), El Pachón (Glencore), and Los Azules (McEwen Copper). In November 2024, the Company announced an updated mineral resource estimate for Altar, prepared by Independent Mining Consultants Inc. (“IMC”) and based on the drilling completed up to and including the 2023-24 field season (independent technical report prepared by IMC, Tucson, Arizona, titled “Technical Report, Estimated Mineral Resources, Altar Project, San Juan Province, Argentina”, dated December 31, 2024 – see news release dated November 25, 2024). In October 2025, the Company announced a Preliminary Economic Assessment for Altar, prepared by SRK Consulting Inc. (“SRK”) (independent technical report prepared by SRK, titled “NI 43-101 Technical Report Preliminary Economic Assessment, Altar Project, San Juan, Argentina”, dated September 30, 2025 – see news release dated October 30, 2025).
About Centauri Minerals Inc.
Centauri Minerals Inc. is a new mineral exploration company focused on Northern Argentina, a mining region of increasing global significance. Centauri holds 100%-interest in a portfolio of exploration projects spanning over 43,000 hectares in the provinces of Salta, Catamarca and Jujuy, which was spun-out from Aldebaran Resources Inc. The most advanced is the Rio Grande gold-copper project located in Salta, which has an independent NI 43-101 compliant mineral resource estimate that highlights significant gold and copper quantities. Centauri has offices and facilities in Salta, Argentina and Vancouver, Canada. It is currently a private company majority owned by Aldebaran Resources Inc. with plans to become a public company in 2026.
Figure 1: Rio Grande Project Location Map – approximately 9 km northwest of the operating Lindero gold copper mine (Fortuna Mining Corp.)
Figure 2: Rio Grande Mineral Resource Areas and Resource Pit Shell
Figure 3: Rio Grande Mineral Resource Block Model and Resource Pit Shell
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