McEwen Copper drills 0.77% copper over 349 metres at Los Azules, Argentina

McEwen Copper Inc., 47.7% owned by McEwen Mining Inc. [TSX, NYSE-MUX], reported assay results from the currently completed drill season at the Los Azules project in Argentina. The prime objectives of this season’s infill drilling campaign were: to confirm the size and grade of the deposit as compared with the 2023 preliminary economic assessment estimate and upgrade the resource categories for the coming feasibility study; test for extensions of mineralization beyond the current pit shell; and explore the company’s large property package for other mineralized areas.

Based on the assay results received to date, the company’s first objective appears to have been met. Initial interpretation suggests that infill drilling will result in an increase in measured and indicated resources and an overall mineral inventory within 5% of the PEA estimate. Testing for extensions beyond the planned pit has successfully encountered mineralization both to the north and to the south.

Primary mineralization was intercepted (202 metres of 0.20% Cu) over 400 metres north of last year’s deep exploration hole, confirming its extension at depth a significant distance to the north. Exploration south of the planned pit has intercepted the principal mineralized intrusive more than 700 metres south of previous drill intercepts and indicates that prospective intrusives continue well to the south of the pit.

Exploration over the property has produced an intriguing target, late in the season. Initial results of a concession-wide regional mapping and sampling campaign have identified strong evidence of a large porphyry system 3 km east of the Los Azules deposit. Porphyry-style veining and quartz vein stockworks with copper oxide mineralization have been recognized within this new target, with assay results pending.

Additionally, this news release covers all results from the first half of the 2023 to 2024 drill program. Final results will be published when all the geochemistry is completed.

The objective of the 2023 to 2024 drilling campaign is to collect all the necessary information to support the completion of the Los Azules feasibility study by early 2025. This information continues to arrive and will be processed in the following months. Resource drilling is focused on converting all the mineralization to be mined in the first five years to measured and indicated resource, to increase confidence during the payback period. Geotechnical, metallurgical, hydrogeological, exploration and condemnation drilling are also being performed.

Highlights: Hole AZ23292 intercepted 349 metres of 0.77% copper (approximately true thickness). The Enriched zone portion of this hole extends over 346 metres and includes an intercept of 232 metres of 0.86% Cu.

Hole AZ23277 intercepted 382.5 metres of 0.54% Cu (approximately true thickness). The Enriched zone portion of this hole extends over 306 metres grading 0.61% Cu and includes an intercept of 74 metres of 0.86% Cu.

The Enriched mineral zone refers to the enrichment of a copper deposit by precipitation-derived water circulation that carries copper minerals downward through the rocks to accumulate in a thick, often horizontal blanket. Immediately above the Enriched zone is the Leached zone, from which copper was removed and transported. Weathering and oxidation often aid in this process. Below the Enriched zone, the Primary (or Hypogene) zone is formed by ascending copper-rich fluids having a much deeper magmatic origin. The green line on the sections indicates the pit floor of the 30-year pit shell from the 2023 NI 43-101 preliminary economic assessment (PEA).

A comprehensive structural model for the deposit has been completed that will provide a better understanding of structural controls on the deposit and aid in future exploration work. Field verification of a previous property-wide structural study using satellite information was carried out in January and has refined the identification of nearby exploration targets.

To date, geological mapping and geochemical sampling have been focused primarily near the Los Azules deposit and only cover roughly 40% of the company’s large concession. To address this limitation, a mapping and sampling campaign was begun in December, to obtain 100% coverage of the company’s concession.

Early results of this work have identified a large new porphyry system 3 km east of Los Azules. Preliminary work has identified porphyry-style veining and alteration, indicating the presence of a porphyry copper system. Areas with strong quartz vein stockworking and the recognition of copper oxides at surface add to the prospectiveness of this newly identified area.

McEwen Copper is a well-financed, private company which owns 100% of the large, advanced-stage Los Azules copper project, located in the San Juan province, Argentina. Los Azules is being designed to be distinctly different from a conventional copper mine, consuming significantly less water, emitting much lower carbon and progressing toward carbon neutral by 2038, and being powered by 100% renewable electricity once in operation. In June 2023, an updated preliminary economic assessment (PEA) was released, which projects a long life of mine, short payback period, low production cost per pound, high annual copper production and a 21.2% after-tax internal rate of return.

Rob McEwen, chairman and chief owner, has a personal investment in the companies of US$220 million. His annual salary is US$1.