Key Highlights

  • Historical diamond drill core at a Warehouse in Villa Nueva was found to be properly stored and in good condition.
  • Access to the San Francisco de los Andes breccia was confirmed.
  • The project is in San Juan province, Argentina.
  • The announcement contains no new assays.

Pioneer Minerals (ASX:PMM) has begun on-ground activity at its San Francisco gold-copper-silver project in San Juan province, Argentina. The start follows an initial reconnaissance visit by its in-country contractor, Andes Exploration, which inspected selected outcrops, historical workings and drill core.

The visit answered three practical questions. Historical diamond drill core stored at a warehouse in Villa Nueva was found to be properly stored and in good condition. Access to the San Francisco de los Andes breccia was confirmed. And the team identified that some road improvements may be needed for future work, while access to other priority areas is still to be verified.

Why the core matters

Old drill core is only useful if it can still be read. Finding it intact means Pioneer can relog it systematically, recording geology, alteration, breccia characteristics and the sequence of mineralising events with modern understanding. That is a relatively low-cost way to test historical interpretations and refine targets before committing to new drilling.

Chief executive Michael Beven said starting field exploration was an important step in assessing the project, and that a disciplined approach would help direct future exploration spending towards the most prospective areas.

The historical results

Interest in San Francisco rests on historical drilling previously reported by Pioneer on 9 October. Highlights include 109 metres at 4.94 grams per tonne gold, 109 g/t silver and 1.13% copper from 12 metres in hole SFDH-012, and 27 metres at 5.50 g/t gold, 97 g/t silver and 3.30% copper from 44 metres in SFDH-003.

These are historical results, not new drilling, and the 4 November announcement contains no new assays. Their value depends on how reliably the original drilling, sampling and assaying were conducted, which is part of what the relogging programme is designed to verify. Investors should therefore treat them as a reason to explore rather than as a confirmed resource.

The breccia pipe target

A breccia pipe is a column of broken rock cemented by mineralising fluids. Such pipes can host high grades, but their size is often limited, so the key questions are how far mineralisation continues laterally and how deep it extends. Pioneer's work is focused on the extent and continuity of known high-grade mineralisation in the San Francisco pipe, including potential depth extensions, as well as other breccia and vein systems across the project.

Why provenance matters

Historical drilling often predates modern reporting standards. Sample handling, assay methods, quality control and survey data may be incomplete or undocumented. Relogging the core, checking collar locations and, eventually, twinning selected holes with new drilling are common ways to establish whether historical data can be relied upon, and whether it can contribute to a resource. Until that work is complete, the intercepts should be viewed with caution.

The work programme

An expanded Andes field team was scheduled to return the following week, subject to access and conditions, to assess priority targets, including areas highlighted by recent geochemical and geological targeting. The programme also includes relogging of selected historical core, field verification and mapping of geochemical targets, integration of new observations into an existing three-dimensional geological model, and assessment of possible geophysical surveys.

Andes has also begun discussions with local service providers and advisers about environmental assessment requirements and preparatory work for a potential environmental impact assessment submission. The scope, timing and regulatory requirements of any submission remain unconfirmed. In Argentina, provincial permitting can significantly affect exploration timelines, so this workstream matters for when drilling might begin.

What to watch

Beven said the company looked forward to reporting progress as field verification, relogging and interpretation advance. Those are the near-term milestones. The bigger test will come if and when Pioneer drills new holes to confirm whether the historical grades and widths can be reproduced.