Pepas West Expanding

·    Ongoing drilling at Pepas West continues to show positive results:

o PEP085, 16.1m @ 2.68g/t Au

o PEP087, 21.7m @ 1.42g/t Au

o PEP088, 9.8m @ 1.41g/t Au

o PEP090, 23.45m @ 2.98g/t Au

·    Hole PEP090 stepped out 30m north of previous holes, demonstrating extension potential. 

·    Rig currently drilling south of Pepas, will return to Pepas West in several weeks.

·    Hole MAP-106 at APTA now in the target zone.

London, May 13th, 2026. Orosur Mining Inc. ("Orosur" or the "Company") (TSXV/AIM:OMI), is pleased to announce an update on the progress of exploration activities at the Company's exploration project at Anzá in Colombia ("Anzá" or the "Project").

Anzá - Colombia

The Anzá Project in Colombia comprises a number of granted exploration titles and applications totalling roughly 330km², within the Mid-Cauca gold belt, west of the city of Medellín.

These titles and applications are owned by two Colombian companies, Minera Anzá, and Minera Monte Aguila, both wholly owned subsidiaries of the Company. The latter of these was acquired by Orosur in November 2024 from the Company's previous JV partners, Newmont Mining and Agnico Eagle Mines. Orosur thus owns 100% of the Anzá Project.

Since acquiring 100% control, the Company has focussed its attention on three prospects:

·    Pepas - a shallow, high-grade ore body of gold mineralisation for which the Company has calculated a Mineral Resource Estimate ("MRE"), announced February 10^th 2026.

·    APTA - a high-grade body of gold mineralisation that has to date seen almost  39,000m of historical drilling, and at which drilling has recently recommenced. 

·    El Cedro - a cluster of gold porphyry intrusions in the south of the Project area that are currently subject to mapping and sampling programs, with a view to potentially being drilled as soon as targets can be finalised and logistics arranged.

Figure 1. Anzá Project

Pepas

The Company's primary focus since reassuming control of the Project in late 2024, was to explore the immediate area of Pepas, ultimately leading to the publication of a maiden MRE for the Pepas gold deposit on February 10^th, 2026.  

This MRE was based upon drilling undertaken by the Company and its previous JV partner from 2022 to late 2025. Results from the final hole included in the MRE, PEP074, were announced on January 8^th, 2026.

Following completion of the MRE drillout in late 2025, the Company then embarked on a semi-regional drilling program around the Pepas deposit. The objective of this drilling program was to better understand the larger scale litho-structural controls that led to formation of the Pepas deposit, such that, in combination with additional mapping and sampling in the wider region, vectors toward additional mineralisation might be developed.

As announced on April 14^th, 2026, a new zone of mineralisation, geologically similar to Pepas, has been discovered approximately 100m west of the main Pepas zone.

This zone had been first identified in two drill holes from early 2025, but only returned to in early 2026 once the Pepas MRE had been completed.

A number of holes (PEP082 to PEP090) have now been completed into this zone, from various positions and in various directions, in order to gain some understanding of the nature, orientation and controls upon this zone. Results thus far are highly encouraging with thick intersections of shallow gold mineralisation being recorded.  Particularly encouraging was PEP090, drilled some 30m NW of previous holes, demonstrating mineralisation over 100m in strike with untested strike extension.

Table 1. Latest drill Intercepts, Pepas Prospect

As previously announced, after completion of hole PEP090, the rig operating at Pepas has been moved southward to other targets, to allow time for geological and assay information from Pepas West to be compiled. This is an ongoing process; however, the Company's geological team note that Pepas West is worthy of follow-up and it is planned that the rig will return here in several weeks to begin to define the size of this mineralised zone.

Figure 2.  Plan of holes, Pepas West

Figure 3. Section PEP084,85,86

Figure 4. Section PEP087

Figure 5. Section PEP088

Figure 6. Section PEP090

APTA

The APTA prospect in the centre of the Project area has seen almost 39,000m of drilling by various companies since 2012. This work has identified a substantial epithermal gold system.

The last phase of drilling was undertaken by the Company's previous JV partner, MMA, from late 2020 through early 2022, at which time the abatement of Covid related operational restrictions allowed MMA field crews to begin to explore the wider Anzá project area. Results from the final holes of this phase of work were announced on 27^th June 2022.

A new phase of drilling was commenced some weeks ago, with hole MAP-106 planned to assess several new geological concepts to assist in planning a larger drill campaign that may, if successful, allow APTA to move to resource status.

Progress of MAP-106 has been very slow due to several zones of difficult and broken ground. However, the hole is now well past 300m and within the target zone. Going forwards, new drill pads are being developed in different locations such that these issues are not repeated.

Orosur CEO Brad George commented:

"It is encouraging to see Anzá now beginning to delivery on its promise. Pepas now has a resource, with more being found nearby, APTA being drilled and El Cedro yet to come."

For further information, visit www.orosur.ca, follow on X @orosurm or please contact:

Orosur Mining Inc

Louis Castro, Chairman,

Brad George, CEO

[email protected]

Tel: +1 (778) 373-0100

SP Angel Corporate Finance LLP - Nomad & Joint Broker

Caroline Rowe / Jen Clarke / Devik Mehta

Tel: +44 (0) 20 3470 0470

Turner Pope Investments (TPI) Ltd - Joint Broker

Andy Thacker/Guy McDougall
Tel: +44 (0)20 3657 0050

Flagstaff Communications and Investor Communications

Tim Thompson
Alison Allfrey
Fergus Mellon

[email protected]

Tel: +44 (0)207 129 1474

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 ('MAR') which has been incorporated into UK law by the European Union (Withdrawal) Act 2018. Upon the publication of this announcement via Regulatory Information Service ('RIS'), this inside information is now considered to be in the public domain.

Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Drill Hole Details - Pepas prospect 2022/2026 Programme*

*Coordinates WGS84, UTM Zone 18

About Orosur Mining Inc.

Orosur Mining Inc. (TSXV: OMI; AIM: OMI) is a minerals explorer and developer currently operating in Colombia and Argentina.

Qualified Persons Statement

The information in this news release was compiled, reviewed, verified and approved by Mr. Brad George, BSc Hons (Geology and Geophysics), MBA, Member of the Australian Institute of Geoscientists (MAIG), CEO of Orosur Mining Inc. and a qualified person as defined by National Instrument 43-101.

Orosur Mining Inc. staff follow standard operating and quality assurance procedures to ensure that sampling techniques and sample results meet international reporting standards.

Drill core is split in half over widths that vary between 0.3m and 2m, depending upon the geological domain. One half is kept on site in the Minera Anzá core storage facility in the case of the Anza Project, or on site in temporary racks in the case of the El Pantano Project, with the other sent for assay.

Industry standard QAQC protocols are put in place with approximately 10% of total submitted samples being blanks, repeats or Certified Reference Materials (CRMs).

Samples for holes PEP-001 to PEP-011 were sent to the Medellin preparation facility of ALS Colombia Ltd, and then to the ISO 9001 certified ALS Chemex laboratory in Lima, Peru.

Samples from PEP-012 onwards are sent to Medellin laboratory of Actlabs for preparation and fire assay, with some sample then sent to the Canadian Actlabs facility for multi element assay

Samples from the EL Pantano project are sent to the preparation facility and fire assay laboratory of Alex Stewart Laboratories in Perito Moreno to be assayed for gold.  Pulps are then sent to the larger Alex Stewart facility in Mendoza for multi-element analysis.

30 gram nominal weight samples are then subject to fire assay and AAS analysis for gold with gravimetric re-finish for overlimit assays of >5 g/t.  ICP-MS Ultra-Trace level multi-element four-acid digest analyses may also undertaken for such elements as silver, copper, lead and zinc, etc.

Gold intersections are reported using a lower cut-off of 0.3g/t Au over 3m.

Intersections are quoted as downhole thicknesses.  True thicknesses are unknown.

Forward Looking Statements

All statements, other than statements of historical fact, contained in this news release constitute "forward looking statements" within the meaning of applicable securities laws, including but not limited to the "safe harbour" provisions of the United States Private Securities Litigation Reform Act of 1995 and are based on expectations estimates and projections as of the date of this news release.

Forward-looking statements include, without limitation, the continuing focus on the Pepas prospect, the exploration plans in Colombia and the funding of those plans, and other events or conditions that may occur in the future. There can be no assurance that such statements will prove to be accurate. Actual results and future events could differ materially from those anticipated in such forward-looking statements. Such statements are subject to significant risks and uncertainties including, but not limited to, those described in the Section "Risks Factors" of the Company's MD&A for the year ended May 31, 2025. The Company's continuance as a going concern is dependent upon its ability to obtain adequate financing. This material uncertainty may cast significant doubt upon the Company's ability to realize its assets and discharge its liabilities in the normal course of business and accordingly the appropriateness of the use of accounting principles applicable to a going concern. The Company disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events and such forward-looking statements, except to the extent required by applicable law.