Extension of Pepas West

• Confirmation of extensive, flat lying body of mineralisation - will test different drilling techniques to accelerate definition.

London, August 5th, 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 Medellín.

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

• Pepas - a shallow, high-grade deposit of gold mineralisation for which the Company has calculated a Mineral Resource Estimate ("MRE"), announced February 10th, 2026.
• APTA - a high-grade body of gold mineralisation that has to date seen approximately 40,000m of drilling, with drilling ongoing.
• El Cedro - a cluster of gold porphyry intrusions in the south of the Project area. Extensive mapping and sampling programs have been undertaken and a rig is currently being mobilised to commence the first drill program ever undertaken at the prospect.

Figure 1. Anzá Project

Pepas

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 and ounces added to inventory.

The Company achieved immediate success with a new zone of shallow mineralisation being identified roughly 100m to the west of Pepas - with first results announced on April 14th, 2026.

Drilling has continued sporadically at Pepas West, with occasional pauses to allow access tracks to be developed, however results from these six additional holes (PEP100 to PEP105) continue to demonstrate an extensive zone of surficial, high grade gold mineralisation.

Table 1. Latest drill Intercepts, Pepas West Prospect

Figure 2. Plan of holes, Pepas West

Initial drilling at Pepas West had suggested the zone was geologically similar to Pepas, with the same mineralising events, but with a different, parallel structural setting.

Recent drilling, however, is developing a more complex picture with the higher-grade surficial mineralisation seemingly a mix of in situ and heavily weathered material that has potentially remobilised downslope from Pepas.

While deeper zones remain unresolved, a picture is emerging of a flat lying, surface mineralised zone of perhaps 10m thick, over a wide area, with mineralisation starting from near surface, grading between 1 and 5g/t Au, and often obscured beneath a thin veneer of barren transported soil.

The zone is extensively weathered, with scattered enclaves of fresh quartz veins, with very little residual geological or structural texture remaining and, as such, the original litho-structural setting is difficult to determine. Additional drilling and geological studies will be undertaken to endeavour to understand the genesis of Pepas West.

The Company considers this free digging, flat lying, surficial, high grade oxide gold mineralisation to be a high priority in a near-term production scenario, from the point of view of cost and time required to define, develop and mine. Thus, instead of the currently employed diamond-core drilling, the Company will examine the potential of utilising a smaller auger rig to more rapidly define the volume and grade of this extensive surface zone, while also examining the potential for an auger system to be used on a regional basis to sample beneath transported cover. This trial is expected to commence in coming weeks.

The current diamond rig will remain on site and be focussed on deeper drilling around Pepas West and other targets.

Figure 3. Long Section, Pepas West

Figure 4. Section PEP101

Figure 5. Section PEP102, PEP103

Figure 6. Section PEP104, PEP105

Orosur CEO Brad George commented:

"The geological nature of Pepas West is complex as a result of mixing of totally weathered and transported material. However, the grade is there which in the end is all that matters. With Pepas entering feasibility and permitting, additional cheap ounces are worth their weight in gold."