RNS RNS RNS12 Jan 2026 07:14
Further to the announcement dated 18 November 2025, Nativo Resources plc (LON:NTVO), a gold-focused mining company with interests in Peru, is pleased to announce that initial assays from surface trenching along interpreted veins within the Tesoro Concession confirm historical data and support Nativo's plan to recommence gold production activities at Bonanza. This confidence is underpinned by positive near-mine sample results and the successful completion of underground rehabilitation and preparation of existing mine workings. Additional prospectivity within the Tesoro Concession has also been confirmed.
The programme (completed and ongoing) covers approximately 400 hectares gathering approximately 250 samples. 20 trenches were excavated at 25-metre intervals to depths of 1.2-1.5 metres to expose the vein structures beneath the colluvial cover. Systematic channel sampling was completed within the surface trenches, with samples taken at 1-metre intervals across the exposed mineralised structures to characterise grade variability along strike. The sampling programme focused on geological mapping, trenching, and geochemical sampling, with the objective of verifying and augmenting the historical gold grades and locations originally identified by St Elias Mines (Figure 1), whose surveys were evaluating near-mine gold mineralisation and structural controls to support production planning and early-stage mining activities, and verifying the geological vein model.
For the Bonanza mine, Nativo's Qualified Person, who designed the ongoing underground mine sampling programme (over 150 samples) has reviewed the sampling and results available, including the St Elias Mines legacy work and the Nativo commissioned sampling programmes, selecting three key surface results (Figure 1), which he considers are representative of the mineralisation along the Bonanza, Tesoro-01 and Tesoro veins and which validate the original St Elias Mines results.
Highlights
Near-Mine High-Grade Gold Mineralisation
Surface sampling returned localised values reaching Au 19.5g/t and averaging Au 10g/t, confirming gold mineralisation associated with narrow mesothermal veins and veinlets in close proximity to existing Bonanza workings. A total of 102 surface rock samples, including rock chip and chip-channel samples, were collected and analysed by Fire Assay with full QA/QC controls at the Certimin laboratory in Lima.
Structural Controls Favourable
Mineralisation is predominantly controlled by NW-SE-trending shear zones and their interaction with the parallel and cross cutting faulting, with three principal structural systems identified (including the Bonanza Vein), each extending up to 1 km in strike length within the concession. These structures are considered favourable for lateral and vertical continuity, an important factor for sustainable mining operations.
Basis For Mine Development
The combination of sample results and completed underground prepara