Operational Update Exploration Footprint Expanding

Orosur Mining Inc - Operational Update. Exploration Footprint Expanding

• Assays for three holes from the Pepas MRE infill and metallurgical program include

o PEP065 - 33.3m @ 2.84g/t Au

o PEP065B - 33.8m @ 2.79g/t Au

o PEP066 (met hole) - 112m @ 5.25g/t Au from surface

• Resource consultants plan to be on site next week to begin the MRE process.
• Soil geochemistry completed at El Cedro, high grade potential confirmed.
• Second Porphyry identified at El Cedro - to be examined in future programs, with a view to drilling early in 2026.
• Airborne magnetic/radiometric survey planned over area.
• Drill rig arrives at the El Pantano Project Argentina to commence first drill program.

London, October 30th, 2025. 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 gold exploration projects at Anzá in Colombia ("Anzá) and El Pantano in Argentina.

Anzá - Colombia

These titles and applications are owned by two Colombia companies, Minera Anzá, and Minera Monte Aguila, both of which are wholly owned subsidiaries of the Company. The latter of these companies 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 body of gold mineralisation that the Company is endeavouring to move to an initial Mineral Resource Estimate in the near term.
• APTA - a high-grade body of gold mineralisation that has to date seen 38,000m of drilling, but is not yet sufficiently understood geologically to allow a MRE to be calculated. The Company plans to undertake additional drilling at APTA in late 2025 with the objective of advancing it toward an MRE as quickly as possible.
• El Cedro - a large gold porphyry system in the south of the Anza Project area. The Company has just completed a large sampling program and plans to undertake a maiden drill program here in early 2026.

Figure 1. Anzá Project

Pepas

As announced on 14th July 2025, the Company took the formal decision to commence infill drilling at its Pepas gold prospect at Anzá, with the objective of moving Pepas to a NI43-101 compliant Mineral Resource Estimate (MRE) by the end of the year.

Drilling progress has recently slowed largely due to issues related to broken ground in hole PEP065 and the need to reconfigure the drill rig for PQ metallurgical drilling followed by the subsequent expected slower pace of advance for this larger diameter core.

Hole PEP-066 was a hole drilled to provide material for detailed metallurgical testing - the hole was drilled using a wider diameter PQ bit to provide additional material for testing and was drilled through the centre of the ore body so as to provide material representative of all mineral domains thus far identified. In order for all domains to be intersected, it was necessary to drill into known ore zones, and thus PEP-066 was drilled very close to several previous holes that had returned high grade intersections.

These three holes have all returned exceptional high grade gold assay results.

Table 1. Latest drill Intercepts, Pepas Prospect

* Hole PEP065 collapsed in broken ground and was redrilled as PEP-065B from the same pad, at a steeper angle

Figure 2. Plan of holes

Figure 3. Section, PEP065 and 65B

Figure 4. Section, PEP066

El Cedro

The El Cedro prospect lies to the south of the same integrated licence that hosts both Pepas and APTA and is roughly 4km 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.

Little work was then undertaken until late 2021, when the Company's previous JV partner MMA re-entered the area to carry out mapping, sampling and ground geophysics that confirmed Anglo American's previous work and mapped several large dioritic intrusions and associated epithermal systems.

The Company subsequently began a large-scale soil geochemical survey in May 2025, planned to cover most of what was thought to be the extent of the porphyry system. Soil samples were taken at roughly 25m intervals, along ridges and spurs for ease of access and to ensure soils were residual.

This survey has just been completed, with gold assay results identifying a substantial, gold bearing system, with highly anomalous geochemical responses over a large, well preserved zoned porphyry system, with soil samples assays at times exceeding 1g/t Au.

Figure 5. El Cedro Soil Samples

Company geological teams have examined these new geochemical data, in conjunction with historical mapping information and airborne geophysical data collected in 2012. An outcome of this work is the hypothesis that El Cedro may in fact consist of multiple porphyry intrusions, with a second potential intrusive system being identified to the south of the known El Cedro porphyry, within the same regional structural corridor.

Of additional interest is apparent associated epithermal systems marginal to both porphyries, with high-grade gold in rock chips having been previously recorded in veins.

Figure 6. El Cedro, multiple porphyry bodies, soils and rock chips

Figure 7. Regional tectonic setting

The Company is now planning additional mapping and soil sampling programs over this southern porphyry. In addition, it has been determined that the older airborne geophysical data, while of value, were of moderate quality and thus it is planned that a more detailed helicopter aeromagnetic and radiometric survey will be undertaken in November or December this year to provide an added layer of lithostructural information about these intrusive systems, the associated epithermal systems, and APTA to the north.

It is expected that drilling at El Cedro could commence in first quarter of calendar 2026.

NI-43-101 Technical Report

The Company's geological consultants are currently well advanced in reviewing all exploration work undertaken at Anzá since the last NI43-101 technical report was published in 2019. An external team is due on site in the first week of November to finalise this program and to observe and assess all of the QAQC processes and procedures.

The primary objective of this work program is the development of an updated NI43-101 Technical Report which may, if deemed appropriate by the consultants, include a Mineral Resource Estimate for the Pepas prospect.

El Pantano - Argentina

The El Pantano Project is an early-stage gold/silver exploration project in Santa Cruz province, southern Argentina.

The Project comprises approximately 550km2 of contiguous granted licences in the prolific Deseado Massif of Santa Cruz, roughly 45km from Anglo Gold's Cerro Vanguardia mining camp and 90km SE of Newmont Mining's giant Cerro Negro mine.

The El Pantano Project is subject to an Exploration & Joint Venture ("JV") agreement ("Agreement") with private Argentinean company DESEADO DORADO S.A.S and its shareholders ("Deseado"), the details of which were announced on February 15th 2022.

The Company currently owns 51% of El Pantano, having met its obligation to spend US$1m in exploration expenditure by February 2025. The Company is now in Phase 2 of the joint venture, whereby it may earn an additional 49% equity in the project (taking the Company to 100% ownership) by investing US$2m in the two years to February 2027. Upon such an event, the original vendors would retain a 2% NSR royalty, 1% of which the Company could purchase for US$1m at its discretion.

At the time the JV commenced, the El Pantano project was a largely untouched grass roots gold/silver exploration project. Some historical sampling and geophysics had been done in the SE of the project, but 80% of the project area had never been explored and no drilling had ever been undertaken anywhere within the Project area.

The Company entered the JV on the basis of regional geological data and field mapping that indicated the potential for a major, previously unknown district-scale low-sulphidation epithermal system.

Post signing, the Company immediately began the process of geological mapping, geochemical sampling and geophysics across the licence package.

This work was completed in late 2024, with all work to date confirming our geological hypothesis that El Pantano is a highly prospective, untouched epithermal system.

Figure 8. El Pantano geology and geochemistry

The Company has taken the decision that the Project is drill ready. A camp has been established in this remote region and a diamond drill rig will arrive on site this week, with a plan to commence drilling in coming days.

The Company has planned a 3000m diamond drilling campaign across various sections of the identified 25km long epithermal structure, targeting geochemical and geophysical anomalies. It is expected this program will continue into late January 2026, allowing for the Christmas break.

This drilling program is designed purely to be reconnaissance in nature. No drilling has ever been undertaken on the El Pantano property, and while surface geological data are encouraging, information related to the vertical zonation is required to develop the exploration model.

Orosur CEO Brad George commented:

"Post our recent capital raising, Orosur is now free to explore. Our strategy of geological selection, 100% ownership and examining near term production is paying dividends, positioning us well in this buoyant gold market".