Extension of Pepas West

Orosur Mining Inc

05 August 2026

Extension of Pepas West

·    Results from six holes released, including:

o PEP101 - 6.4m @ 2.81g/t Au from surface

o PEP102 - 6.85m @ 2.18g/t Au from surface

o PEP103 - 10.2m @ 5.77g/t Au from surface

o PEP104 - 19.8m @ 1.77g/t Au from surface

o PEP105 - 15m @ 2.03g/t Au from surface

·    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.

These titles and applications are owned 100% by two Colombian companies, Minera Anzá and Minera Monte Aguila, both wholly owned subsidiaries of the Company.

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 10^th, 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

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.  

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 14^th, 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.

Hole Number	From (m)	To (m)	Interval (m)	Au (g/t)
PEP100	18.15	24.15	6	0.65
PEP101	0	6.4	6.4	2.81
including	1	5.3	4.3	3.83
PEP102	0	6.85	6.85	2.18
including	0.9	5.15	4.25	3.24
PEP103	0	10.20	10.20	5.77
including	0	2.45	2.45	22.3
PEP104	0	19.8	19.8	1.77
including	9	18.85	9.85	2.71
PEP105	0	15	15	2.03
including	0	5.5	5.5	3.24

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."

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

Orosur Mining Inc

Louis Castro, Chairman,

Brad George, CEO

info@orosur.ca

Tel: +1 (778) 373-0100

SP Angel Corporate Finance LLP - Nomad & Joint Broker

Jen Clarke / Caroline Rowe / 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

orosur@flagstaffcomms.com

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*

Hole ID	Easting (m)	Northing (m)	Elevation asl (m)	Dip (°)	Azimuth (°)
PEP-001	403384	705000	1001	-50	150
PEP-002	403384	705000	1001	-60	290
PEP-003	403240	705142	1001	-49.60	95.2
PEP-004	403508	705671	838	-59.8	99.8
PEP-005	403373	704990	1008	-49.8	94.6
PEP-007	403374	704990	1008	-69.9	170
PEP-008	403232	704803	971	-50	60
PEP-009	403032	705057	1055	-50	80
PEP-010	403375	705106	982	-50.31	190.4
PEP-011	403573	704939	1001	-50.3	255
PEP-012	403415	704890	997	-56	352
PEP-013	403413	704887	997	-50	43
PEP-014	403400	704910	1007	-50	43
PEP-015	403375	704938	1017	-50	43
PEP-016	403326	704912	999	-50	43
PEP-017	403365	704848	976	-40	47
PEP-018	403345	704851	977	-45	43
PEP-019	403446	704890	991	-45	43
PEP-020	403446	704890	991	-75	43
PEP-021	403424	704935	1012	-62	223
PEP-022	403424	704935	1012	-42	223
PEP-023	403245	704927	969	-50	43
PEP-024	403245	704927	969	-78	43
PEP-025	403369	704888	1001	-45	43
PEP-026	403339	704955	1008	-63	50
PEP-027	403468	704909	1003	-46	228
PEP-028	403398	704957	1012	-58	223
PEP-029	403311	705018	1011	-50	50
PEP-030	403311	705018	1011	-50	000
PEP-031B	403486	704901	998	-52	220
PEP-032	403431	704861	982	-60	15
PEP-033	403431	704861	982	-65	100
PEP-034	403431	704861	982	-45	315
PEP-035	403369	704882	996	-45	223
PEP-036	403311	705152	989	-45	30
PEP-037	403354	705227	958	-50	210
PEP-038	403332	705219	967	-45	128
PEP-039	403411	704798	957	-45	73
PEP-040	403369	704882	995	-80	212
PEP-041	403373	704936	1008	-50	3
PEP-042	403396	705038	716	-50	82
PEP-043	403298	704942	981	-50	43
PEP-044	403402	704948	1011	-62	33
PEP-045	403406	704949	1011	-60	223
PEP-046	403420	704933	1007	-53	43
PEP-047	403414	704927	1008	-74	223
PEP-048	403448	704922	1005	-54	043
PEP-049	403447	704920	1005	-55	223
PEP-050	403459	704905	1003	-45	43
PEP-051	403391	704928	1011	-61	43
PEP-052	403391	704928	1011	-87	43
PEP-053	403391	704929	1012	-60	223
PEP-054	403380	704954	1011	-52	43
PEP-055	403380	704954	1011	-86	223
PEP-056	403371	704970	1012	-61	43
PEP-057	403371	704970	1012	-71	223
PEP-058	403371	704970	1012	-85	223
PEP-059	403384	704976	1007	-59	43
PEP-060	403372	704908	1005	-55	43
PEP-061	403361	704988	1010	-80	223
PEP-062	403361	704988	1010	-61	43
PEP-063	403345	705005	1009	-50	80
PEP-064	403356	704923	1005	-51	43
PEP-065	403359	704949	1008	-59	43
PEP-065B	403359	704949	1008	-50	43
PEP-066	403423	704938	1009	-64	223
PEP-067	403400	704870	990	-53	43
PEP-068	403342	704989	1010	-56	43
PEP-069	403342	704987	1010	-80	218
PEP-070	403260	705071	1013	-50	30
PEP-071	403333	705005	1009	-51	90
PEP-072B	403435	704879	989	-70	43
PEP-073	403423	704917	1006	-50	307
PEP-074	403423	704917	1006	-60	127
PEP-075	403240	705267	946	-50	221
PEP-076	403240	705267	946	-60	042
PEP-077	403304	705228	959	-60	042
PEP-078	403304	705228	959	-60	222
PEP-079	403304	705228	959	-50	120
PEP-080	403093	705100	1026	-50	042
PEP-081	403215	705006	984	-55	032
PEP-082	403261	704941	977	-58	190
PEP-083	403267	704913	972	-45	342
PEP-084	403267	704913	972	-50	125
PEP-085	403267	704913	972	-50	310
PEP-086	403272	704910	979	-55	310
PEP-087	403262	704941	977	-50	260
PEP-088	403252	704946	979	-50	202
PEP-089	403252	704946	979	-50	202
PEP-090	403238	704980	976	-45	200
PEP-091	403390	704583	959	-45	110
PEP-092	403390	704583	959	-50	270
PEP-093	403351	704530	946	-45	123
PEP-094	403351	704530	946	-45	30
PEP-095	403215	705006	984	-55	205
PEP-096	403215	705006	984	-45	245
PEP-097	403215	705006	985	-50	178
PEP-098	403210	704940	965	-45	037
PEP-099	403210	704940	965	-62	037
PEP-100	403210	704940	965	-45	082
PEP-101	403274	704916	973	-55	035
PEP-102	403343	704863	985	-60	188
PEP-103	403343	704863	985	-50	08
PEP-104	403347	704897	998	-50	220
PEP-105	403347	704897	998	-75	040

*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

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.

This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact rns@lseg.com or visit www.rns.com.
RNS may use your IP address to confirm compliance with the terms and conditions, to analyse how you engage with the information contained in this communication, and to share such analysis on an anonymised basis with others as part of our commercial services. For further information about how RNS and the London Stock Exchange use the personal data you provide us, please see our Privacy Policy.