Sendero Resources Updates Exploration Model for Peñas Negras Project in Argentina

October 8, 2026 — Leads & Copy — Sendero Resources Corp. has announced updated interpretations of airborne magnetic survey data from its Peñas Negras Project in La Rioja, Argentina. The findings refine the exploration model and highlight targets for both epithermal and porphyry-style mineralization, suggesting the project may host a cluster of mineralized systems.

The advanced interpretation, utilizing 3D inversion and classification of aeromagnetic data, has generated a geological model of Peñas Negras extending to approximately 3 kilometers in depth. This model reveals several distinct, kilometer-scale magnetic bodies interpreted as oxidized intrusions, which are characteristic of magmas associated with copper-gold and molybdenum porphyry deposits.

A preserved lithocap, considered a favourable host for epithermal mineralization, is present across a significant portion of the project, indicating that the upper levels of the system remain intact. Interpreted intrusions are observed from subcrop down to the maximum inversion depth. The presence of stacked lithocap layers further suggests that more than one hydrothermal event has occurred at the site.

Near-vertical zones of magnetite-destructive alteration have been identified, which may represent deep fluid pathways, potentially extending beneath known mineralization at the La Ollita occurrence. These findings provide valuable insights for future exploration efforts.

Jeremy Gillis, Interim CEO of Sendero, stated, "For the first time, we can see Peñas Negras in three dimensions. The model shows several large intrusive centres, a preserved lithocap and deep structures. Together, they point to a potential cluster of mineralized systems rather than a single target, with settings for both epithermal and porphyry-style mineralization. Historical drilling also shows the system sits where you want it: the top hasn't been eroded away, and the intrusive rocks beneath it are within drilling reach."

The classification of the aeromagnetic data identified four distinctive magnetic units: lithocap (lowest susceptibility), magnetite-destructive alteration (low to moderate), andesitic host rock (moderate), and interpreted intrusions (highest susceptibility). The lithocap typically forms a thin, flat-lying layer, while the magnetite-destructive alteration is observed as thick horizontal layers with near-vertical chimneys. The andesitic host rock comprises the majority of the model volume, and the intrusions appear as steep, pipe-like bodies cutting through the host rock.

Analysis of cross-sections from the model provides further detail. At La Ollita, the model shows lithocap at the surface with a root zone of magnetite-destructive alteration extending beneath known mineralization, while historical drilling was shallow and did not test the deeper parts of the system. At Cerro Verde Sur, shallow drilling in 2026 intersected anomalous gold in the lithocap but did not reach the underlying strongly magnetic body, which remains untested.

At Cerro Verde Norte, historical drilling by Anglo American intersected lithocap hydrothermal breccia near the surface and granitic intrusive rocks at depth, consistent with the model's predictions. The nature of this granite, whether it is a mineralizing intrusion or older basement, is yet to be determined.

The Peñas Negras project is located in the Vicuña Belt in Argentina, an area known for similar geological characteristics to other deposits in the region. Multiple porphyry and high-sulfidation epithermal targets have been identified within the project's concessions, which cover a total area of 211.77 square kilometers.

The scientific and technical information in this release was reviewed and approved by Steven McMullan, P. Geo., a consultant to the Company and a qualified person as defined by National Instrument 43-101 Standards of Disclosure for Mineral Projects.

Source: Sendero Resources Corp.