Ancient Paleochannel Systems Of Nechí River Identified As Key Gold Bearing Structures

MEDELLÍN, COLOMBIA - Mineros S.A. reported on Mineral Resource and Mineral Reserve (MRMR) estimates for the Company’s Nechí Alluvial Gold Property, located in the Antioquia Department, Colombia. These estimates, with an effective date of December 31, 2024, were prepared in accordance with National Instrument 43-101 (NI 43-101) and will be supported by a technical report. Mineros’ Nechí Alluvial Property is located approximately 190 km north-northeast of Medellín in the northeast of the Antioquia Department, covering the municipalities of El Bagre, Zaragoza, Caucasia, and Nechí.

The Nechí Alluvial Property hosts classic alluvial gold deposits, which have been commercially exploited for gold by dredging since 1937. Historical gold production from the Nechí alluvial deposits from 1895 to 2024 is approximately 9.1 Moz Au, of which Mineros’ operations account for approximately 3.2 Moz Au.

The alluvial deposits extend for more than 50 km along the Nechí River, with widths up to 3.5 km. The current active area of alluvial operations extends approximately 12.5 km on the east side of the Nechí River towards the northern part of the property.

The updated MRMR reflects recent exploration success, resource modeling enhancements, and economic evaluations.

Andres Restrepo, President and Chief Executive Officer said, “We are pleased to announce this updated Mineral Reserve and Mineral Resource estimate to the market. We are confident that it will improve our investors’ understanding of the Nechí Alluvial Property, demonstrate the value of the asset, and enable us to optimize our extraction of the gold contained therein.”

Mineros has prepared a LOM plan based on Proven and Probable Mineral Reserves, extending over approximately 12 years from 2025 to 2036. The LOM plan includes pit optimization, pit design, mine scheduling, and the application of modifying factors to the Measured and Indicated Mineral Resources. Total dredging production averages 43.6 Mm3 from 2025 to 2032 with the peak mining rate of 53.7 Mm3 in 2027. Diluted gold grade peaks in 2036 at 111 mg/m3. Over the life of mine, bucket line dredging accounts for approximately 78% of total production (overburden and mineralization).

Gold mineralization is hosted within stratified sedimentary sequences of the Nechí River valley, primarily within coarse gravel units interbedded with lenses of silt, sand, and clay. The distribution of gold is strongly correlated with granulometry, with coarse gravel units typically exhibiting higher gold concentrations. Ancient paleochannel systems of the Nechí River have been identified as key gold-bearing structures, providing continuity for resource modeling and estimation. The unique geological setting and predictable mineralization styles of the Nechí deposit support its potential for long-term alluvial gold production.

Mineros has completed a Mineral Resource estimate for the Nechí Alluvial Property incorporating 12,490 drill holes totaling 290,673.2 m. This estimate marks the transition from conventional 2D polygonal estimation to a 3D block modeling approach, significantly enhancing the spatial accuracy, geological continuity, classification of resources, optimized mine planning, and better operational decision-making.  The use of Leapfrog 3D modeling software has enabled the delineation of geological domains and the distinction between production zones, overburden, and bedrock, aligning resource estimation practices with industry best standards.

The Mineral Resource estimate comprises a total Measured and Indicated volume of 527 Mm³ grading 56 mg/m³ Au, containing approximately 1,005 koz of gold. In addition, Inferred Resources total 223 Mm³ grading 62 mg/m³ Au, for 447 koz of gold. The updated resource model is reported within an ultimate pit shell generated at a Revenue Factor of 1.0 using an average, long-term gold price of US$1,900/oz and an exchange rate of COP$4,000.00 = US$1.00, and includes low-grade blocks situated within the pit shell. The estimate is exclusive of Mineral Reserves and depleted by the mined-out areas.