Andina Copper drills porphyry copper system at Piuquenes North

May 28, 2026 – Vancouver, British Columbia. - Andina Copper Corp. is pleased to report that diamond drill holes PIU12 and PIU13, the first two holes designed to test the large, deep-seated low resistivity Magnetotelluric ("MT") geophysical anomaly at the Piuquenes Project North target (see News Release dated February 10, 2026 ), were completed to final depths of 992.60m and 1,235m, respectively. Both holes intersected multiple intrusive phases associated with porphyry-style copper sulphide mineralization within a newly identified intrusive complex at Piuquenes North. HIGHLIGHTS Both PIU12 and PIU13 confirmed the presence of copper sulphide mineralization at depth within the approximately 800m by 700m MT anomaly targeted by the current drill program.   Hole PIU13 intersected four porphyry intrusive phases, confirming the presence of a well-developed porphyry system at the previously untested Piuquenes North target.   The strongest visible copper sulphide mineralization in PIU13 was observed between 848m and 1,045m downhole, hosted within an early mineral porphyry phase.   Copper sulphide minerals, including chalcopyrite and bornite, were logged throughout the early mineralized porphyry, occurring within quartz veins and as disseminations associated with potassic alteration.   Hole PIU12 confirmed the lateral extent of the porphyry system, intersecting andesitic host rocks intruded by pre-mineral porphyry dykes containing chalcopyrite and minor bornite mineralization.   Assay results for both PIU12 and PIU13 are pending.   Joseph van den Elsen, President and CEO of Andina Copper, commented: "During the 2025/26 San Juan field season we continued to define and expand the recently discovered Piuquenes East copper-gold porphyry centre, while also testing a compelling undrilled MT geophysical target at Piuquenes North.

Both drill holes completed at Piuquenes North intersected a multiphase porphyry copper system, with the MT anomaly remaining open to the north and at depth. Confirmation of a third mineralized porphyry system at Piuquenes North marks an important milestone for the project and further demonstrates the significant exploration potential of the Piuquenes property. We now eagerly await assays results for both PIU12 and PIU13 and look forward to further advancing the systematic evaluation of our highly prospective 2,500-hectare land package in San Juan Province, concurrent with the rapid exploration of the Cobrasco Project in Colombia.”   Figure 1 : Piuquenes Cu Au project location map, San Juan Province, Argentina.

Geology and Mineralization – Drill Hole PIU13 Drill hole PIU13 was completed at an azimuth of 50 degrees and a dip of minus 70 degrees to a final depth of 1,235m. The hole intersected three principal lithological domains, corresponding to the colour scheme shown in the accompanying cross section. 0 to 665m, andesitic volcanic host rock, locally intruded by porphyry dykes carrying chalcopyrite mineralization. 665 to 1,045m, pre-mineral and early mineral porphyry intrusive phases associated with the main zone of copper sulphide mineralization intersected in the hole. From 665m to 848m, the intrusive complex is characterized by potassic alteration overprinted by sericite and chlorite alteration.

Below this interval, from 848m to 1,045m, the hole intersected moderate to strong potassic-altered early mineral porphyry hosting the strongest visible copper sulphide mineralization observed to date at Piuquenes North. Mineralization consists of chalcopyrite and bornite occurring within A and B-type quartz veins, as well as disseminations. 1,050m to 1,235m (end of hole), intermineral and late mineral porphyry. From 1,050m to 1,096m, the intermineral phase shows lower intensity potassic alteration with chalcopyrite and bornite in A and B type veins with potassic feldspar halos.

Below 1,096m, a dioritic late mineral porphyry with weaker alteration and reduced vein density persists to 1,129m. From 1,129m to 1,168m, the hole returned to intermineral and early mineral porphyry with moderate to strong potassic alteration, elevated A and B type vein density and chalcopyrite-bornite mineralization, with bornite prominent in veinlets and potassic feldspar halos. From 1,168m to end of hole at 1,235m, a coarse-grained dioritic late mineral porphyry exhibits weak to locally moderate potassic alteration, overprinted by retrograde chlorite-sericite-pyrite alteration in fault zones, with reduced vein density and minor chalcopyrite-bornite in early veinlets.

The final 23m (1,212–1,235m) exhibited a subtle increase in veinlet density and may represent a distal facies of the intermineral porphyry or a distinct late intrusive phase. Geology and Mineralization – Drill Hole PIU12 PIU12 was drilled at an azimuth of 255 degrees and a dip of minus 70 degrees to a final depth of 992.60m. The hole intersected andesitic volcanic host rocks over the upper 832m, with dykes and apophyses of pre-mineral porphyry intruding the volcanic sequence throughout the interval.

From 832m to the end of hole at 992.60m, PIU12 intersected the main body of the pre-mineral porphyry. The intrusive exhibits moderate potassic alteration overprinted by sericite and chlorite alteration and contains A and B-type quartz veinlets carrying pyrite, chalcopyrite and trace bornite mineralization. Results from PIU12 confirm the lateral continuity of the porphyry system at Piuquenes North.   Figure 2: Plan view MT resistivity at 2,500m RL with PIU12 and PIU13 drill hole traces, Piuquenes North MT anomaly (800m × 700m).

Piuquenes Central and Piuquenes East shown for context.   Figure 3: Cross-section A–A' looking south-southeast showing PIU12 and PIU13 drill holes plotted against MT resistivity. Piuquenes Central and Piuquenes East shown for context.     Figure 4: PIU13 core photos (NQ core, 47.6mm diameter). Assays pending.   Figure 5: PIU12 core photos (HQ core 62.5mm diameter at 384m and 680m; NQ core 47.6mm diameter at 901.5m).

Assays pending. Relationship Between Observed Mineralization and the MT Anomaly Drill holes PIU12 and PIU13 successfully tested the deep low-resistivity MT anomaly at Piuquenes North and confirmed the presence of a well-mineralized multiphase porphyry system within the targeted volume. Both holes intersected porphyry-style alteration and abundant sulphide mineralization, including chalcopyrite and bornite hosted in quartz veins and disseminations within the intrusive complex.

The Company believes the elevated sulphide content observed in drilling is a significant contributing factor to the conductive low-resistivity response defined by the MT survey. The geometry and scale of the mineralized porphyry system intersected by PIU12 and PIU13 demonstrate a strong correlation between the MT anomaly and copper sulphide mineralization at Piuquenes North. The anomaly remains open to the north and at depth, where additional drilling will be required to further evaluate the extent of the system.

During the off-season, the Company plans to undertake laboratory resistivity and chargeability measurements on representative core samples to further refine the geophysical interpretation of the Piuquenes North target.    Next Steps Assay results from both PIU12 and PIU13 remain pending. Upon receipt, the Company will integrate the assay results together with updated geological logging, including lithology, alteration and mineralization, into an updated geological model for Piuquenes North. The integrated dataset will be used to refine the targeting strategy for follow-up drilling, which is expected to focus on the down-dip and along-strike extensions of the newly intersected porphyry system at Piuquenes North.

Click Image To View Full Size   Table 1: Drill Hole Collar Information - Piuquenes North in UTM Zone 19 South. Note: All technical information included in this News Release is based solely on visual logging of drill core. Core from completed sample intervals has been dispatched to ALS Minerals (Mendoza, Argentina) for preparation and onward analysis at the ALS laboratory in Lima, Peru.

Assay results at Piuquenes North remain pending and unreported. The Company's Corporate Presentation is available at: Andina Copper Corporate Presentation Interested parties can subscribe to our mailing list and follow our social media channels in the links below: Mailing List | | Andina Copper X   ON BEHALF OF THE BOARD Joseph van den Elsen President & Chief Executive Officer joseph@andinacopper.com Jordan Webster VP Technical Communications jordan@andinacopper.com   QAQC Drill holes PIU12 and PIU13 were collared using a PQ drill bit and reduced to HQ and subsequently NQ diameter as drilling progressed. Drill core was extracted from the core barrels by the drilling contractor under the supervision of Andina Copper personnel and placed in labelled core boxes with appropriate depth markers.

At the Piuquenes field camp, the core was geologically logged, photographed, and checked for recovery by Company geologists. Sample intervals, two metres in length, were defined and marked for cutting prior to the core boxes being secured and transported by Company personnel to the Company's core processing facility in Barreal, San Juan Province, Argentina. At the Barreal facility, the core was cut using a diamond saw.

One half of the core was placed in sealed sample bags for analysis while the remaining half was retained for reference and stored at the Company's secure core storage facility in Barreal. Samples were assigned unique reference numbers, weighed, and transported to the ALS Minerals sample preparation facility in Mendoza, Argentina, an independent and accredited laboratory. Prepared pulps were then forwarded to the ALS laboratory in Lima, Peru for analysis.

Gold was analysed by 30 g fire assay with atomic absorption finish (Au AA23), copper by four acid digestion with ore grade atomic absorption finish (Cu OG62), and multi element analyses by ICP MS (ME MS61). The Company implemented a quality assurance and quality control (QA/QC) program that included the insertion of certified reference materials, blanks, and duplicates at regular intervals within the sample stream. Notes: No assay results are reported in this release.

All references to mineralization, alteration assemblages, vein densities and sulphide content reflect visual core logging by Company geologists and are preliminary. Visual estimates of sulphide content are not, and should not be construed as, grade estimates. True widths have not yet been determined.

QUALIFIED PERSON Gustavo Zulliger, a consultant of Andina Copper Corp and a "Qualified Person" ("QP") within the definition of that term in National Instrument 43 101, Standards of Disclosure for Mineral Projects, has reviewed and approved the technical information that forms the basis for this news release. Gustavo Zulliger is a Certified Professional Geologist at the American Institute of Professional Geologists (CP AIPG CPG 11165). ABOUT ANDINA COPPER Andina Copper Corporation is a unique South America focused copper explorer listed on the TSX Venture Exchange (TSXV:ANDC), Frankfurt (FSE: FIR), and OTC (OTCQB: PMMCF) exchanges.

The Company holds two significant discoveries along the world's premier copper producing Andean porphyry belt in Argentina and Colombia, and a compelling undrilled copper gold target in the prolific copper production district of the Coastal Cordillera of Chile. FORWARD LOOKING STATEMENT This news release contains certain statements that may be deemed "forward looking statements". All statements in this release, other than statements of historical fact, that address events or developments that Andina Copper expects to occur, are forward looking statements.

Forward looking statements are statements that are not historical facts and are generally, but not always, identified by the words "expects" and similar expressions, or that events or conditions "will" or "may" occur. These statements are subject to various risks. Although Andina Copper believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, such statements are not guaranteeing of future performance, and actual results may differ materially from those in forward looking statements.

Neither the TSXV nor the Canadian Investment Regulatory Organization accepts responsibility for the adequacy or accuracy of this release.   Copyright (c) 2026 TheNewswire - All rights reserved. TheNewsWire May 28, 2026 - 3:00 AM PDT News by QuoteMedia www.quotemedia.com