Colombia update

• High grade and highly anomalous rock chip, channel and soil samples across a wide area at Pepas increase the prospectivity of the region.
• Historical sampling results from the El Cedro and El Roble prospects suggest highly prospective porphyry system that the Company plans to follow up in the near term.

London, October 22nd 2024. 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 Anzá Project ("Project") in Colombia.

As announced on September 10th 2024, the Company has signed a definitive, binding Share Purchase Agreement ("SPA") that once completed, would see the Company returning to 100% ownership of the Anzá Project, in return for deferred, production based consideration.

The Anzá project comprises a number of granted exploration licences and applications on the prolific Mid-Cauca belt of Colombia, approximately 50km west of Medellin. The total licence package previously under joint venture currently totalled some 175km2 in area, however the size of the Project may increase substantially with additional applications made by the Company and acquired as part of the SPA.

Figure 1. Anzá Project - Prospect Locations

Pepas Prospect

The Pepas Prospect is in the northern extents of the Anzá Project, over 10km north of the central base at APTA.

Field work commenced at Pepas in late 2021 as the gradual abatement of Covid allowed field crews to venture further afield from APTA base.

Mapping work by the Company's JV partner identified Pepas as a small window of attractive altered tuffs and other volcanics, roughly 1000m x 500m in size, along the main structure thought to control mineralisation in the vicinity (Figure 2).

Figure 2, Pepas Prospect.

The area is rugged, thickly wooded and heavily weathered, with sparse outcrop. Where identified, rock chip samples were taken and this work identified highly anomalous results, with assays at times in excess of several grammes per tonne of gold over a wide area (Figure 3). In particular, a small outcrop of silicified tuff, roughly 20m2 in size was identified and channel sampled in early 2022, returning assays between 3.41g/t Au to 95.5g/t Au.

Drilling of hole PEP-001 was commenced in June 2022, positioned to intersect the interpreted depth extension of this anomalous outcrop. Assay results from PEP-001, announced on September 6th, 2022, showed high grade gold mineralisation from surface, with the hole returning a composite intersection of 150.90m @ 3.0g/t Au from surface.

Two additional holes were then drilled from this same pad, with results announced on October 21st 2022, with PEP-005 returning 35.5m @ 2.12g/t Au and PEP-007 returning 80.55m @ 3.05g/t Au. (Figure 3).

Later holes at the Pepas prosect were drilled some considerable distance from this original drill pad, and did not return similar results. It is the view of the Company that the form, orientation and controlling structures of the gold mineralisation at Pepas, first identified in hole PEP-001, remain unresolved by this later drilling, and that the Pepas target remains largely untested.

Figure 3. Pepas Prospect, detailed scale - drilling and sampling

During 2024, while the Company was negotiating the return of the Project from its JV partners, staff at the Company were granted access to the Pepas site in order to commence the necessary logistical planning and social and community liaison to allow the Company to drill once the agreement had completed.

As part of this process, the Company's geological teams undertook more detailed sampling and geological mapping across the Pepas prospect to gain a better understanding of potential geological controls to target future drilling.

The Company's exploration teams carried out soil and rock chip sampling across the prospect, concentrating on roads and tracks that had been newly opened to facilitate planned drilling. In addition, the Company identified two abandoned artisanal mining tunnels (A and B, Figure 3) close to the original silicified tuff targeted by hole PEP-001.

Channel rock-chip sampling of the new tracks have identified a large extent of highly anomalous mineralisation over an area roughly 120m in length, with multiple rock chip results over 2g/t Au, several over 5g/t Au and one of 80g/t Au.

The abandoned artisanal tunnels were entered and mapped by the Company's geological teams, taking 1m composite channel samples along the entire length of each tunnel, roughly 20m in each case.

Figure 4. Channel sampling results, artisanal tunnel A

Figure 5, Channel sampling results, artisanal tunnel B

Mapping of these tunnels not only showed the same lithologies and alteration as seen in nearby drilling (andesites, tuffs, silicification and brecciation) but similar or higher gold grades.

The first tunnel sampled (tunnel A), returned channel sample assays varying from 0.35g/t Au to 10.16g/t Au (Figure 4), while the second tunnel (tunnel B), returned high-grade gold assays for most of its length (Figure 5), up to a maximum of 195g/t Au near the mouth of the tunnel.

The Company considers these results to be highly encouraging not only in the exceptional grades measured but the large area over which they were recorded. In addition, the lithologies and structures mapped in the tunnels have provided greater geological context to the gold mineralisation intersected in hole PEP-001, some 61m distant from tunnel B (Figure 6).

In order to better define the orientation and controls of this mineralisation, the Company plans to locate several new holes collared near the entrance of tunnel B, oriented such as to intersect PEP-001 and the holes beneath. It is anticipated that once the orientation of mineralisation is better defined, its scale can then begin to be assessed with gradual step out drilling.

In the meantime, geological teams continue mapping and sampling to better define the prospect.

Figure 6. Pepas cross section

El Cedro/El Roble

El Cedro and El Roble were two prospects to the south of the Project area that were first identified as a result of mapping and geochemical surveys by Anglo American before the Company acquired the Anzá Project.

As with Pepas, the region remained largely untouched until the abatement of Covid.

Geological mapping and sampling began in these southern prospects in 2022, ramping up in 2023. Interpretation of later mapping and sampling results suggests that El Cedro and Roble could potentially be different parts of the same porphyry system. Porphyry lithologies and alteration assemblages have been mapped over a roughly 2km x 2km area, with extensive areas of quartz veining with highly anomalous gold values up to 10g/t Au (Figure 7).

Following the technical completion of the SPA, which the Company is actively progressing, the Company plans to mobilise geological teams to map the area in more detail, with the objective of identifying drill targets.

Figure 7. El Cedro and El Roble geology and rock chip samples

Orosur CEO Brad George commented:

"Mapping and sampling by ourselves and our previous JV partners are showing the enormous potential across the Anzá project. Pepas particularly is showing excellent numbers and we are aiming to be drilling here in the short term."

Orosur Mining Inc.

Louis Castro, Chairman,

Brad George, CEO

SP Angel Corporate Finance LLP - Nomad & Joint Broker

Jeff Keating / Caroline Rowe

Turner Pope Investments (TPI) Ltd - Joint Broker

Andy Thacker/James Pope

Flagstaff Communications and Investor Communications

Tim Thompson

Mark Edwards

Fergus Mellon