Mr. Louis Castro reports

OROSUR MINING INC - EL PANTANO PROJECT DEVELOPING

Orosur Mining Inc. has provided an update on the company's exploration project at El Pantano in Argentina.

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 560 square kilometres of contiguous granted licences in the prolific Deseado massif of Santa Cruz province, roughly 45 kilometres from Anglo Gold's Cerro Vanguardia mining camp and 100 km southeast of Newmont Mining's giant Cerro Negro mine.

El Pantano was subject to an exploration and joint venture agreement with private Argentine company Deseado Dorado SAS and its shareholders, the details of which were announced on Feb. 15, 2022.

The JV agreement required exploration expenditure of $3-million (U.S.) over five years from Feb. 14, 2022, in two phases to earn 100-per-cent ownership of the project. The company has completed the first phase of the JV agreement, having invested $1-million (U.S.) over three years, as announced on Feb. 17, 2025. With the recently completed drilling program, the company has now completed the phase 2 commitments of $2-million (U.S.) ahead of the required deadline and, as such, has exercised its option to retain 100-per-cent ownership of the project.

As part of the phase 2 obligations, the company has granted to the original vendors a 2-per-cent NSR (net smelter return) royalty on future production, 1 per cent of which the company may purchase for $1-million (U.S.) at its discretion.

Exploration work

While displaying positive surface geology, the project had seen little historical modern exploration, apart from some superficial geochemical and geophysical work in the southeastern quadrant by a previous company. No drilling had ever been undertaken within the project area.

Since inception of the JV agreement, the company had conducted large-scale reconnaissance mapping, sampling, geochemical and geophysical programs across the project area. Results of these work programs supported the company's thesis that the project had the potential to host a major epithermal mineral system.

As a result, the company then committed in late 2025, to the first drill program ever undertaken within the project area.

Commencing in November, 2025, 24 diamond drill holes, for a total of 5,533 metres were completed across the project area, targeted to address a number of geological areas:

• Test sources of geochemical anomalism;
• Assess a variety of induced polarization responses;
• Intersect, if possible, mineralized structures indicative of the low-sulphidation epithermal model being postulated at El Pantano;
• Gain understanding of the vertical variations in the system, especially in relation to the potential for fluid boiling.

In a general sense, the broad objective of the program is to determine if a mineral system is present at El Pantano and, if so, develop exploration plans for further work.

Drill holes were spread across the eastern and western extremes of the main rift related epithermal system, with several sections being completed to facilitate an assessment of lateral and vertical variations in geochemistry and structures.

Full results and discussion of the project and all work undertaken are included in the technical report (compliant with National Instrument 43-101, Standard of Disclosure for Mineral Projects) dated July 13, 2026, with effective date May 15, 2026, which has been filed on SEDAR+ and is available to view on the company's website.

Discussion of drilling results

The rift-related, low-sulphidation epithermal model being employed at El Pantano sees gold and silver mineralization being derived from deep, underlying intrusives and then concentrated in quartz veins at a higher level in structures developed as part of the macro-scale Jurassic rifting. At the vertical scale, development of economic mineralization is often driven by fluid boiling as gold-bearing fluids rise up and binding pressures are relaxed.

A key objective then of the drilling campaign, was to intersect such structures and to gain some information of the vertical zonation and potential proximity and vectors toward mineralization.

El Pantano West: structurally controlled gold-bearing vein corridors

El Pantano West target area is interpreted to represent a structurally controlled low-sulphidation epithermal domain hosted mainly by Jurassic volcanic rocks of the Bajo Pobre formation. Drilling, geological logging and structural measurements from core indicate a hierarchy of principal vein corridors, subsidiary vein structures and faults. These structures are interpreted to form part of an integrated hydrothermal system rather than isolated mineralized occurrences.

Initial scout drilling at El Pantano West returned multiple gold-bearing intervals associated with interpreted vein corridors. Examples include DH_ELP003, which returned 18.0 metres at 0.46 gram per tonne gold, including 4.9 m at 0.79 g/t Au; DH_ELP018, which returned several gold-bearing intervals including 27.12 m at 0.20 g/t Au and narrower higher-grade subintervals; and DH_ELP023, which intersected multiple broad anomalous gold-bearing intervals, including 27.0 m at 0.14 g/t Au, 23.6 m at 0.13 g/t Au and 20.7 m at 0.12 g/t Au.

These early results are interpreted as evidence of a structurally controlled gold-bearing hydrothermal system developed across multiple vein corridors.

The current drilling appears to have tested only selected portions of the interpreted structural system. Of particular interest is the central-western part of the El Pantano West section, where several interpreted principal structures appear to converge and where multiple gold-bearing intervals have been encountered. This structural convergence may represent a more focused fluid pathway or potential feeder zone that warrants additional drill testing at depth and along strike.

The exploration potential at El Pantano West is not interpreted to be limited to depth alone. Near-surface copper anomalism and multiple gold-bearing intercepts suggest that the hydrothermal footprint may extend laterally beyond the current drilling. This supports the potential for additional prospective structures along the broader corridor, subject to further exploration and drill confirmation.

El Pantano East: silica cap and advanced argillic alteration target

In the eastern part of the project, El Pantano East displays a different but complementary expression of the same broader hydrothermal system. Geological, geochemical and geophysical data indicate the presence of silica cap development, argillic to advanced argillic alteration, strong pathfinder geochemistry and conductive geophysical responses. The eastern domain is interpreted to represent a higher-level or more preserved part of the hydrothermal system, where volatile-rich pathfinder elements such as arsenic are more strongly expressed at or near surface.

Drilling sections from El Pantano East show broad arsenic-rich pathfinder intervals beneath the interpreted silica cap and argillic alteration zone, including DH_ELP015 with 125.5 m at 232 parts per million As and DH_ELP014 with 60.85 m at 174 ppm As. These arsenic intervals are interpreted as pathfinder geochemical responses. However, in the context of epithermal systems, the presence of broad arsenic anomalism, silica cap development, argillic alteration and interpreted feeder structures supports the concept of a preserved high-level hydrothermal environment that warrants follow-up testing for deeper or laterally offset precious metal targets.

Summary

The west-to-east zonation at El Pantano is a key outcome of the technical report and provides an important framework for future exploration. The western target areas show a stronger association of gold, copper and base metal responses, interpreted as representing relatively deeper or more eroded levels of the hydrothermal system. In contrast, the eastern target areas are characterized by silica cap development, argillic to advanced argillic alteration and stronger volatile pathfinder element expression, interpreted as potentially higher-level or more preserved portions of the system.

The western and eastern domains are interpreted to form part of a vertically and laterally zoned epithermal system controlled by a regional northwest-southeast structural corridor. This integrated model provides multiple exploration vectors, including structurally controlled gold-bearing vein corridors in the west, possible feeder structures at depth, newly identified regional soil anomalies south of the principal structure and preserved pathfinder-rich alteration zones in the east.

The company views these results as supportive of its thesis that the project hosts a significant epithermal mineral system and thus worthy of further exploration.

Suggested work programs are outlined in the technical report. The company will consider these suggestions and will develop exploration plans over the winter recess.

Orosur chief executive officer Brad George commented: "Starting exploration from scratch is never easy, but the work carried out by our team support our initial view of the extraordinary prospectivity of El Pantano. We now own the project 100 per cent and so have many options available to us."

Orosur Mining is a minerals explorer and developer currently operating in Colombia and Argentina.

Qualified person statement

The information in this news release was compiled, reviewed, verified and approved by Brad George, BSc (honours) (geology and geophysics), MBA, member of the Australian Institute of Geoscientists (MAIG), CEO of Orosur Mining and a qualified person as defined by NI 43-101.

Orosur Mining 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 0.3 metre and two metres, depending upon the geological domain. One-half is kept on site in the Minera Anza 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 quality assurance/quality control protocols are put in place, with approximately 10 per cent of total submitted samples being blanks, repeats or certified reference materials (CRMs).

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 multielement analysis.

Thirty-gram-nominal-weight samples are then subject to fire assay and AAS analysis for gold with gravimetric refinish for overlimit assays of greater than five g/t. ICP-MS ultratrace-level multielement four-acid-digest analyses may also undertaken for such elements as silver, copper, lead and zinc.

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

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

We seek Safe Harbor.