Orosur Mining drills 61.35 metres of 0.93 g/t gold at Anza Project, Colombia

Orosur Mining Inc. [TSXV: OMI, AIM] provided an update on the progress of exploration activities at the company’s exploration project at Anza in Colombia.

The Anza Project comprises a number of granted exploration titles and applications totalling roughly 530 km², within the Mid-Cauca gold belt, west of Medellin.

These titles and applications are owned 100% by two Colombian companies, Minera Anza and Minera Monte Aguila, both wholly owned subsidiaries of the company.

Since acquiring 100% control of the project, the company has focused its attention on three prospects. Pepas: a shallow, high-grade orebody of gold mineralization for which the company has calculated a mineral resource estimate (MRE), announced Feb. 10, 2026. Apta: a high-grade body of gold mineralization that has to date seen approximately 40,000 metres of drilling since 2012, with drilling continuing. El Cedro: a cluster of gold/copper porphyry intrusions and associated flanking hydrothermal systems in the south of the project area at which drilling has just commenced, with first results released today.

The El Cedro prospect lies to the south of the same integrated licence that hosts both Pepas and Apta and is roughly four kilometres south of the Apta base camp.

Work on the area began some years before Orosur’s tenure, when Anglo American undertook reconnaissance mapping and sampling, identifying a highly prospective gold/copper porphyry system. An extensive area of anomalous soil geochemistry was delineated, as well as channel samples and rock chip samples with assays up to 10 grams per tonne gold and 2% copper. No drilling was undertaken.

The prospect did not progress until late 2021, when the company’s previous joint venture partner, MMA, re-entered the area to carry out mapping, sampling and ground geophysics that largely confirmed Anglo American’s previous work and mapped two large dioritic intrusions and associated hydrothermal systems within a broad north-south structural corridor. No drilling was undertaken.

Postresumption of control of the project in November, 2024, the company completed larger-scale surface mapping programs, geochemical surveys and drone-mounted magnetic surveys, focusing on identifying structures and hydrothermal features proximal to the intrusions that could have the potential for higher-grade metal accumulations.

First drilling commenced at the El Cedro system on August 26, 2026. The first drill hole at El Cedro (CED001) was positioned on the southeastern flank of the northern intrusion, close to the major structures that divide the northern and southern intrusions and are viewed as having controlled the emplacement of these systems and subsequent hydrothermal development.

The multiple objectives of CED001 were to test the flanks of the northern intrusion for potential intrusion-related alteration that might produce wider-scale mineralization and to intersect possible downdip extensions of multiple high-grade vein systems that had been exposed in the adjacent creek system.

Assays for the first 61.35 metres have been received, with the entire interval being mineralized, for a composite intersection of 61.35 metres at 0.93 g/t gold. The final sample of this assayed interval returned 1.25 grams per tonne gold. This zone also returned anomalous copper, however, at levels deemed below economic significance.

Shallow zone: The upper part of CED001 has intersected a complex sequence of strongly altered and locally brecciated rocks displaying evidence of multiple hydrothermal events.

Early logging has identified brecciated rocks containing porphyritic igneous and host-rock fragments affected by secondary biotite alteration and subsequent quartz-feldspar-related veining. More detailed logging subsequently recognized zones of secondary biotite, magnetite and pyrrhotite, locally associated with strong silicification and repeated millimetre-scale veining.

The geological relationships observed to date are interpreted to indicate a multistage intrusive-hydrothermal system, with an early high-temperature alteration event subsequently affected by repeated fracturing, brecciation, silicification and sulphide-bearing fluid flow.

Vein zone: CED001 was anticipated to intersect the vertical projection of the first of a set of high-grade surface veins and structures at 100 metres downhole.

At roughly 99 metres downhole, CED001 entered a wide zone of polymetallic veining, demonstrating strongly silicified rocks containing abundant quartz-carbonate-sulphide veins containing pyrrhotite, pyrite, galena, sphalerite and locally chalcopyrite, within a broader alteration halo.

These deeper intervals display a notable increase in vein and veinlet density, being more closely comparable with the gold-bearing polymetallic veins observed at surface than to the alteration assemblage associated within the currently assayed upper interval.

Channel sampling of the surface veins (upon which CED001 was targeted) returned values of up to 8.83 g/t gold; however, the veins interpreted to have been intersected in this current zone were the lowest grade of those at surface, at less than 0.5 g/t gold, suggesting that vein scale and tenor may increase substantially with depth.

The vertical projection of the higher-grade surface veins are interpreted to be potentially intersected at various points deeper in the hole; however, given the increased depth extrapolation, uncertainty increases substantially.

Samples from 61.3 metres to 86 metres have been submitted for assay this week, with results expected in the near term. Further samples, including those from the vein zone, should be submitted to the laboratory later this week.

CED001 is currently at 130 metres. The hole is planned to extend to 500 metres and is expected to be completed by the end of the month.

The company considers these results from the first hole ever drilled on the prospect to be highly encouraging, as evidence of a substantial porphyry/hydrothermal mineralized system. Only one rig is currently dedicated to the El Cedro system, with two more holes planned to be drilled in different directions from the same pad once CED001 is complete. However, these plans may be reviewed as the hole progresses, and a more detailed geological picture develops.

Brad George, Orosur CEO, commented: “Real grassroots discoveries have become very rare in modern times — and we possibly have two … so far. This is testament to the geological potential of the Anza project and Colombia as an exploration destination, but mostly to the talent and dedication of the local team.”

Orosur Mining is a minerals explorer and developer currently operating in Colombia and Argentina.

Gold intersections are reported using a lower cut-off of 0.3 g/t gold over 3 metres. Intersections are quoted as downhole thicknesses. True thicknesses are unknown.