Mr. John Black reports

ALDEBARAN INTERCEPTS 565.60 M OF 0.60% CUEQ, INCLUDING 329.60 M OF 0.80% IN HOLE ALD-23-228: DRILLING HAS RECOMMENCED TO DEEPEN HOLE AS IT TERMINATED IN HIGH-GRADE MINERALIZATION

Aldebaran Resources Inc. has released results for holes ALD-23-227 and ALD-23-228 from its continuing drilling campaign at the Altar copper-gold project in San Juan province, Argentina.

Hole ALD-23-227 was a 200-metre stepout hole to the north from previously released ALD-22-223 (1,167.50 m of 0.48 per cent copper equivalent (CuEq) -- see March 1, 2023, press release). ALD-23-228 was a 200 m stepout to the north from previously released ALD-23-225B (951.20 m of 0.60 per cent CuEq -- see May 31, 2023, press release).

Both holes have provided valuable additional pierce points into the promising geophysical anomaly beneath and lateral to current resources at the Altar project. In addition, both ALD-23-227 and ALD-23-228 tested the northern extension of the newly identified Altar United trend.

ALD-23-227 entered favourable host rocks at approximately 1,000 m depth, and then returned attractive-grade mineralization until the end of the hole. ALD-23-228 hit the favourable host rock formation at approximately 750 m depth and thereafter returned some of the highest-grade copper mineralization encountered on the project to date, demonstrating that the high-grade mineralization found previously in hole ALD-23-225B has continuity.

Highlights

ALD-23-228:

• 565.60 m of 0.60 per cent CuEq from 676 m depth;
  • Including 474.60 m of 0.69 per cent CuEq from 767 m depth;
    • Including 329.60 of 0.80 per cent CuEq from 912 m depth;
      • Including 58 m of 1.02 per cent CuEq from 1,011 m depth.
• Hole ended in 74.60 m of 0.80 per cent CuEq with the last sample running 0.96 per cent CuEq.
• The company has re-entered hole ALD-23-228 and is actively drilling to test for the deeper extension of this higher-grade mineralization.

ALD-23-227:

• 198.50 m of 0.50 per cent CuEq from 1,040 m depth;
  • Including 60.50 m of 0.63 per cent CuEq from 1,178 m depth.
• Hole ended in 31.50 m of 0.69 per cent CuEq.

John Black, chief executive officer of Aldebaran, commented as follows: "Hole 228 represents another remarkable run of mineralization and represents some of the better grades we've seen at the Altar project. We have restarted drilling on hole 228 to see if the higher-grade mineralization continues to depth. The Altar system continues to grow well beyond what was previously understood. The resource we have in hand already represents one of the largest undeveloped copper projects in the world; however, with the mineralization we've been hitting in recent drill results, we expect it to grow substantially."

Dr. Kevin B. Heather, chief geological officer of Aldebaran, commented as follows: "Both holes reported today demonstrate that the new Altar United trend continues to deliver solid runs of higher-grade mineralization that build onto the previous higher-grade intercepts reported recently in holes 223, 224 and 225B. With these new results, it's clear that Altar United is delivering continuity of higher-grade mineralization, within an already very large Altar system, that will add additional higher-grade tonnage. The upper portions of holes 227 and 228 both drilled through less favourable rhyolite host rocks, and while they didn't return exceptional grades, it demonstrates that even poor host rocks can be mineralized in this strong system. The lower-grade intervals reported today will likely report to resource at a break-even cut-off grade, which typically hovers around 0.1 per cent CuEq, thus potentially reducing the strip ratio."

Discussion of results

ALD-23-227

Drill hole ALD-23-227 was collared 200 m north of ALD-22-223 (see company news release dated March 1, 2023). It was drilled at a minus-75-degree inclination and a 180-degree azimuth. The final depth of the hole was 1,238.50 m.

Drill hole ALD-23-227 intersected a package of strongly fragmental dacitic crystal tuff over the first 428 m, then transitioned to less favourable but weakly mineralized massive rhyolite, which continued to a depth of 1,179.60 m. The hole then transitioned into the better mineralized diorite porphyry intrusive rocks until the end of the hole, with mineralization increasing toward the bottom of the hole.

The base of oxidation in hole ALD-23-227 is only 26 m depth. Alteration in this hole is characterized dominantly by white sericite-pyrite-tourmaline-quartz assemblages and sporadic pyrite-enargite-anhydrite/anhydrite-carbonates-chalcopyrite-sphalerite structures and veins. This white sericite alteration overprints, and locally obliterates, an earlier green sericite-chalcopyrite-pyrite assemblage from the very first metres of the hole up until approximately 750 m depth, leaving only local windows of the earlier green sericite assemblage. Beyond 750 m depth, the green sericite-chalcopyrite-pyrite assemblage progressively increases along with an associated increase in both chalcopyrite and quartz-chalcopyrite-pyrite-molybdenite veins.

From 843.80 m to 1179.60 m depth, white sericite-pyrite-quartz alteration is of moderate intensity and associated with an increase in the occurrence of chalcopyrite. In this interval, the rhyolite porphyry has some relicts of biotite-magnetite-K-feldspar (potassic) alteration, which is overprinted by increasing green sericite-chalcopyrite-anhydrite assemblages associated with halo-style veins (as documented in nearby holes 223, 224 and 225B).

From 1,179.60 m to the end of the hole, biotite-K-feldspar-magnetite-chalcopyrite-bornite (potassic) is the dominant alteration in the diorite porphyry intrusion, but is also overprinted by moderate intensity, green sericite-quartz-anhydrite-chalcopyrite-(chalcocite) alteration mineralization, pervasively developed in the halos of hairline veins. A substantial increase in the frequency of quartz-chalcopyrite-pyrite-molybdenite veins is also observed toward the bottom of the hole.

ALD-23-228

Drill hole ALD-23-228 was collared 212 m north of ALD-23-225B (see company news release dated May 31, 2023). It was drilled at a minus-75-degree inclination and a 180-degree azimuth. The final depth of the hole was 1,241.60 m (drilling has restarted on this hole to deepen it).

Similar to drill hole ALD-23-227, hole 228 intersected a package of strongly fragmental dacitic crystal tuffs from surface to 205.30 m. These volcaniclastic rocks overlie a long run of massive rhyolite extending to a depth of 805 m, followed by more favourable andesitic volcanic host rocks until 918.55 m depth and then from there until the bottom of the hole within well-mineralized diorite porphyry intrusive rocks.

The oxidation profile in ALD-23-228 is poorly developed in the upper portion of the hole, with the occurrence of sulphides from near surface and minor jarosite-goethite-hematite in fractures up to the base of oxidation at approximately 266 m depth.

Alteration within the upper crystal tuff and rhyolite units is characterized dominantly by the occurrence of white sericite-pyrite-tourmaline-quartz assemblages with minor pyrite-enargite-anhydrite/anhydrite-carbonates-chalcopyrite-sphalerite vein structures overprinting an earlier green sericite-quartz-chalcopyrite-pyrite alteration. D-type veins, which are typically late in the development of porphyry copper systems, are very frequent in the upper portion of the hole, with a lesser number of high-sulphidation structures, all crosscutting earlier quartz-green sericite-chalcopyrite-pyrite and white quartz-chalcopyrite-moly veins.

A major change in the style of alteration occurs within the andesite volcanic rocks and the diorite porphyry units below approximately 805 m depth. From this depth and to the bottom of the hole, the white sericite-pyrite assemblages decrease considerably, and the dominant alteration is characterized by an early, strongly developed biotite-K-feldspar-chalcopyrite potassic assemblage overprinted by a green sericite-quartz-anhydrite-chalcopyrite-(chalcocite) assemblage associated with the halos on hairline veins, both of which are well mineralized.

These halo-style veins are pervasive and obliterate the original texture of the rock and are associated with very high copper grades due to abundant fine-grained sulphides consisting of chalcopyrite-pyrite-bornite-molybdenite. Occurrence of these halo veins also corresponds with an increasing frequency of quartz-chalcopyrite-pyrite-molybdenite veins, which in most cases are crosscutting the halo-style veins.

Project update

The company is actively drilling with four rigs. Holes ALD-23-229, ALD-23-230, ALD-23-231 and ALD-23-189EXT are completed and were terminated at 1,413.60 m, 611.40 m, 1,211.80 m and 1,246 m respectively; all pending final assays. Hole ALD-23-189EXT is an extension of a historically drilled hole, ALD-12-189, which was originally terminated at 592 m depth. At the date of this release, holes ALD-23-232, ALD-23-124EXT and ALD-23-228EXT were active and at approximately 1,064.70 m, 751 m and 1,358.70 m depths, respectively. Hole ALD-23-124EXT is an extension of a historically drilled hole, ALD-12-124, which was originally terminated at 226.50 m depth. A fourth rig just commenced drilling on hole ALD-23-233 and will not reach its planned target depth during the current campaign but will be left in good standing in order to re-enter and continue the hole at the start of the next field campaign. The company plans to begin demobilizing the drill rigs and then shut down the camp to close out the 2022/2023 drill campaign in the coming week.

Webinar

For more context, please join the company in a live event on Thursday, June 8, at 11 a.m. EST/8 a.m. PST. A question-and-answer will follow the presentation.

Qualified person

The scientific and technical data contained in this news release have been reviewed and approved by Dr. Heather, BSc (honours), MSc, PhD, FAusIMM, FGS, chief geological officer and director of Aldebaran, who serves as the qualified person (QP) under the definitions of National Instrument 43-101.

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 has the right to earn up to an 80-per-cent interest in the Altar copper-gold project in San Juan province, Argentina, from Sibanye Stillwater Ltd. 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 Pachon (Glencore) and Los Azules (McEwen Copper). In March, 2021, the company announced an updated mineral resource estimate for Altar, prepared by Independent Mining Consultants Inc. and based on the drilling completed up to and including 2020 (independent technical report prepared by Independent Mining Consultants, Tucson, Ariz., titled "Technical Report, Estimated Mineral Resources, Altar Project, San Juan Province, Argentina," dated March 22, 2021 -- see news release dated March 22, 2021).

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