Colombian Mining & Exploration
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Orosur Mining (AIM: OMI)

Orosur Mining (AIM: OMI) is a gold explorer focused on its 100%-owned Anzá project west of Medellín. There it has a small, high-grade maiden resource at Pepas and a new porphyry discovery at El Cedro. Orosur Mining stock raised C$16 million in October 2026 to fund three drill rigs and early permitting at Pepas.

Tickers: AIM: OMI | TSXV: OMI · Headquarters: London, United Kingdom · Data as of: Nov 4, 2026

Orosur Mining at a glance

ProjectDepartmentCommodityStageOwnership
Anzá: Pepas and Pepas WestAntioquiagoldresource defined100%
Anzá: APTAAntioquiagolddrilling100%
Anzá: El CedroAntioquiagold, copperdrilling100%
Market capRefresh at publication (C$0.32 placement price, Oct 2026, for reference only)
Shares outstanding452,196,324 after C$16M placement (Oct 6, 2026)
CashUS$7.84M at Aug 31, 2026; about US$16.84M after the Oct 6, 2026 placement (Q1 FY2027 MD&A)
Latest financingC$16.0M: 50M units at C$0.32, each with a half warrant at US$0.32 for 24 months; Red Cloud Securities sole agent (closed Oct 6, 2026)
Anzá resourcePepas: Indicated 201 koz Au at 5.46 g/t + Inferred 18 koz (NI 43-101, effective Jan 16, 2026)
Fiscal yearEnds May 31; FY2026 net loss US$5.95M
UpcomingAGM and special meeting Nov 16, 2026 (Toronto)

About Orosur Mining

Orosur is listed on London’s AIM market and the TSX Venture Exchange, both under OMI. It has a Toronto-registered office, and its news releases are issued from London. It used to operate the San Gregorio gold mine in Uruguay. Uruguay and Chile are now reported as discontinued operations. The company focuses on Colombia (Anzá) and Argentina (El Pantano), and in July 2026 it exercised its option to own 100% of El Pantano.

Anzá covers about 530 km² in the Mid-Cauca gold belt, about 50 km west of Medellín, in Antioquia. About 170 km² are granted titles and about 360 km² are applications. Orosur holds the titles through two Colombian subsidiaries, Minera Anzá and Minera Monte Águila (MMA). From 2020 to 2024 the project was run under MMA, a 50/50 joint venture of Newmont and Agnico Eagle. Orosur bought MMA back with no upfront payment, completing the purchase on November 28, 2024. Its later filings describe the consideration as deferred and contingent on future production.

Since regaining control, Orosur has defined a maiden resource at Pepas (February 2026), drafted a PTO (Colombia’s mine work plan) for Pepas, and made a new gold-copper porphyry discovery at El Cedro (September–October 2026). Three drill rigs were running at Anzá in September 2026, one each at Pepas, APTA and El Cedro.

After the October 2026 placement, Orosur had about US$16.8 million in cash, which it says lasts into late 2027. It has 452.2 million shares in issue. The annual and special meeting is on November 16, 2026.

Orosur Mining’s Colombian projects

Anzá: Pepas and Pepas West

Pepas was discovered in early 2022 in the north of the Anzá licence. It is an intermediate-sulphidation epithermal gold system, meaning gold-bearing veins formed by hot fluids at shallow depth, hosted in volcanic sedimentary rocks. Mineralization starts at surface. After regaining 100%, Orosur drilled 79 holes (10,592 m). The February 2026 maiden resource, prepared by Bara Consulting, assumes a small open pit to about 100 m depth and a 250,000 t/year operation at US$3,000/oz gold. The NI 43-101 technical report was filed in March 2026.

Pepas West, about 100 m west of Pepas, is a shallow, oxidized, flat-lying zone of medium grade, with PEP106 returning 19.45 m at 1.02 g/t gold. Orosur is testing it with an auger to about 10 m depth. On October 14, 2026 the company said it had completed the final draft of the Pepas PTO and would begin consultation with the ANM, Colombia’s national mining agency. That starts the permitting path for a possible small mine. Orosur says it cannot disclose the PTO’s technical details because the PTO is not NI 43-101 compliant.

Resources: Indicated 1.14 Mt at 5.46 g/t Au (201,000 oz) + Inferred 0.19 Mt at 2.99 g/t Au (18,000 oz), 0.92 g/t cut-off, open-pit constrained (NI 43-101, effective Jan 16, 2026)

Anzá: APTA

APTA is a high-grade epithermal gold system with more than 39,000 m of drilling since 2012 by Orosur and earlier joint-venture partners. Current work targets its shallower parts and the structures that control higher grades.

On June 9, 2026 Orosur reported new mineralized zones, led by hole MAP-106A at 229.7 m at 0.88 g/t gold. On July 14, 2026 it reported that hole MAP107 returned 135.5 m at 1.91 g/t gold, including 49 m at 4.06 g/t, and ended in mineralization. A later hole, MAP108, returned a broad, lower-grade 78.95 m at 0.38 g/t gold.

Resources: No mineral resource yet.

Anzá: El Cedro

El Cedro sits on the same integrated licence as Pepas and APTA, about 4 km south of the APTA base camp. Orosur sees it as a gold-copper porphyry cluster: a large, lower-grade system around intrusions, linked to two diorite bodies. Drilling started in late August 2026 after a long permitting period. It is the first drilling ever done there.

The first hole, CED001, returned 267.4 m at 0.65 g/t gold from surface, including 46.3 m at 1.0 g/t from 19.2 m and narrow veins above 3 g/t. Mechanical problems stopped it before its 500 m target. It ended in mineralization. A twin hole, CED001A, is being drilled to reach 500 m, and multi-element assays are pending at labs outside Colombia.

Resources: No mineral resource yet.

Latest Orosur Mining news

Upcoming catalysts

  • Multi-element assays from CED001 and results from the 500 m twin hole CED001A at El Cedro
  • ANM consultation on the Pepas PTO, then the environmental licence, needed before any mining
  • Pepas West auger results, which could add to the Pepas resource
  • Follow-up drilling at APTA after MAP107
  • AGM and special meeting, November 16, 2026
  • El Pantano (Argentina) exploration plans after the southern winter

Management

  • Brad George, Chief Executive Officer
  • Louis Castro, Executive Chairman

Key risks for Orosur Mining stock

  • The Pepas resource is small (about 219,000 oz in total), so a mine would be modest without more discoveries.
  • Permitting: the Pepas PTO and environmental licence are early in the process, and part of the land package is applications, some in a forest reserve or along the Cauca River.
  • El Cedro is based on a single hole. Grade and size are unproven, and the hole ran into mechanical problems.
  • Funding and dilution: no revenue, US$16.8M of cash, half-warrants outstanding and a history of yearly placements.
  • The deferred, production-linked consideration owed to the former owners of MMA (Newmont and Agnico Eagle) could reduce future mine economics. Terms were not disclosed in sources reviewed.
  • Antioquia security and informal mining are risks across the Mid-Cauca belt.

Sources

Related: Colombian stocks · Companies & Projects tracker · Colombian exploration companies

Educational information only, not investment advice. Figures are from the sources listed and dated; check the company’s latest filings before relying on them. See our Disclosure & Editorial Policy.