Orosur Mining Inc Announces Colombia update

• Assays received from four additional diamond holes at Pepas and Pupino.
• Results provide guidance for future targeting.
• Near-term focus will shift from drilling to groundwork to better define local structural controls.
• Finalisation of Phase 2 of JV continuing.

LONDON, UK / ACCESSWIRE / December 2 2022 / Orosur Mining Inc. ("Orosur" or the "Company") (TSXV:OMI,AIM:OMI), is pleased to announce an update on the progress of exploration activities at the Company's flagship Anzá Project ("Project") in Colombia.

The Project is the subject of an Exploration Agreement with Venture Option ("Exploration Agreement") with Colombian company Minera Monte Águila ("MMA"). MMA is itself a 50/50 joint venture ("JV") between Newmont Corporation ("Newmont") (NYSE:NEM, TSX:NEM) and Agnico Eagle Mines Limited ("Agnico") (NYSE:AEM,TSX:AEM), and is the Colombian vehicle by which these two companies jointly exercise their rights and obligations with respect to the Exploration Agreement over the Project.

MMA is the operator of the Project after exercising its right to assume operational control in the second half of 2021.

Assay Results
Assay results for four additional diamond drill holes from the Pepas and Pupino prospects have been received.

Both the Pupino and Pepas prospects are located in the northern region of the Anzá Project, roughly 8km and 12km, respectively north-northeast from the central APTA prospect that had seen most drilling at Anzá up until early 2022.

Key intersections are noted below.

Table 1. Drill Intercepts.

Geology and Drilling
Drilling activities commenced at Pepas in April 2022, and at the nearby Pupino prospect soon afterward. Assay results from the first six holes from Pepas were released on September 6^th ,2022 and October 21^st ,2022, which included thick, high grade gold intersections in holes PEP001 (150.90m @ 3.00g/t Au), PEP005 (36.85m @ 2.85m Au) and PEP007 (80.55m @ 3.05m Au).

All three of these holes were drilled in different orientations from the same drill pad, with gold mineralisation starting from surface. While the intersections were encouraging, the fact that the drill pad was positioned within the mineralised body, with holes drilling outward, was problematic in terms of being able to effectively define the shape and orientation of the body and so provide guidance for later drilling.

Two new drill pads were constructed some 200m southwest and 300m northwest respectively from the original drill pad to drill holes PEP008 and PEP009 (Figure 1). Moving the rigs to the west was based on the assumption that the mineralised body dipped toward the west, and therefore these two holes were targeted at the presumed down-dip extension, vertically below the previous drilling.

Figure 1. Drill Plan, Pepas Prospect

PEP006
PEP006 was the last of a group of earlier holes drilled some distance to the north of the mineralised body intersected at PEP001 and was drilled to a depth of 882m. No significant gold intersections were encountered; however, this was expected as previous drilling in the area (PEP004) had also been negative.

PEP008 and PEP009
PEP008 was drilled from the southwest toward the northeast to test directly below the mineralised intersections identified in holes PEP001. The hole was drilled to a depth of 647m. The step back for this new pad was substantial such that PEP008 passed some 220m vertically below PEP001.

PEP009 was drilled to a depth of 602m well north of the previously identified mineralised body and was intended to test an interpreted faulted offset extension of the Pepas body based upon surface mapping and low-level gold mineralisation that had been previously intersected in hole PEP003 (announced September 6^th, 2022). Again, the step back was substantial with PEP009 projected to intersect the targeted structures over 300m below previous drilling.

Both holes intersected mineralised structures, largely as expected, but with lower levels of gold mineralisation than intersected in previous drilling.

Subsequent analysis and interpretation of drill core from these and previous holes has now suggested three distinct phases of structurally controlled veining, with the youngest phase being the polymetallic sheeted veining that produced the thick intersections of high-grade gold intersected at Pepas in earlier holes. It is also likely that these various vein systems have different orientations, with the most important potentially dipping away from hole PEP008. As a result, hole PEP008, being drilled from the west, may have drilled under this important later structure.

PUP002
PUP002 was drilled to the south at the Pupino prospect to a depth of 301m to test several mapped structures that showed evidence of epithermal alteration. The hole intersected several veins with sulphide mineralisation, but with no substantial gold anomalism.

As noted previously, drilling at Pupino had ceased some time ago due to logistical difficulties and the need to develop new camp facilities.

Temporary Suspension of Drilling
The Company has been informed that MMA has decided to temporarily suspend drilling activities at the Project to focus on field mapping, sampling and trenching activities will continue across the Project to define further drilling targets, including additional surface works specifically in the Pepas prospect area.

Phase 2 of Exploration Agreement.
As previously announced on September 9^th, 2022, MMA has provided the Company with a "Phase 1 Earn-In Notice", thereby effectively notifying the Company of MMA's intention of moving to Phase 2 of the Exploration Agreement. Phase 2 would cover a period of a maximum of four years, over which time MMA would be required to invest US$20M in the Project.
As previously noted, this process entails the formation of a new Mining Company, the governance of which will be based on terms in the existing Exploration Agreement. The process is progressing on schedule and is expected to be completed in the next few months.

Orosur CEO Brad George commented:

"While these drill results are not as exciting as hoped, this is not surprising. Epithermal gold systems by their nature are complex and several phases of drilling are often required to properly define the geometry before more substantial drilling can then be undertaken. In the meantime, we continue the work necessary to create the corporate structure for the MMA-Orosur joint venture and hope to have this in place in the next few months."

For further information, visit www.orosur.ca , follow on twitter @orosurm or 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
Jeff Keating / Caroline Rowe
Tel: +44 (0) 20 3 470 0470

Turner Pope Investments (TPI) Ltd - Joint Broker
Andy Thacker/James Pope
Tel: +44 (0)20 3657 0050

Flagstaff Communications and Investor Communications
Tim Thompson
Mark Edwards
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 - 2020/2022 Programme*

* Coordinates WGS84, UTM Zone 18

About Orosur Mining Inc.

Orosur Mining Inc. (TSXV: OMI, AIM: OMI) is a minerals explorer and developer focused on identifying and advancing projects in South America. The Company operates in Colombia, Argentina and Brazil. It has discontinued operations in Uruguay.

About the Anzá Project
Anzá is a gold exploration project, comprising three exploration licences, four exploration licence applications, and several small exploitation permits, totalling 207.5km2 in the prolific Mid-Cauca belt of Colombia.

The Anzá Project is currently wholly owned by Orosur via its subsidiary, Minera Anzá S.A.

The project is located 50km west of Medellin and is easily accessible by all-weather roads and boasts excellent infrastructure including water, power, communications and large exploration camp.

The Anza?? Project is subject to an Exploration Agreement with Venture Option dated September 7th, 2018, as announced on September 10th, 2018, between Orosur's 100% subsidiary Minera Anza?? S.A ("Minera Anza??") and Minera Monte A??guila SAS ("MMA"), a 50/50 joint venture between Newmont Corporation (NYSE:NEM, TSX:NGT), and Agnico Eagle Mines Limited (NYSE:AEM, TSX:AEM).

Qualified Persons Statement
The information in this news release was compiled, reviewed and verified 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 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, with the other sent for assay.

Industry standard QAQC protocols are put in place with approximately 20% of total submitted samples being blanks, repeats or Certified Reference Materials (CRMs).

Samples are sent to the Medellin preparation facility of ALS Colombia Ltd, and then to the ISO 9001 certified ALS Chemex laboratory in Lima, Peru.

30-gram nominal weight samples are then subject to fire assay and AAS analysis for gold with gravimetric re-finish for overlimit assays of >10g/t. ICP-MS Ultra-Trace level multi-element four-acid digest analyses is 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.

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 exploration plans in Colombia and the funding from MMA of those plans, MMA's decision to continue with the Exploration Agreement, the formation of a new mining company or mining venture to hold the Project, the ability for Loryser to implement the Creditor´s Agreement successfully in Uruguay and other events or conditions that may occur in the future. The Company's continuance as a going concern is dependent upon its ability to obtain adequate financing, to reach profitable levels of operations and to reach a satisfactory implementation of the Creditor´s Agreement in Uruguay. These material uncertainties 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. 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, those as described in Section "Risks Factors" of the MDA and the Annual Information Form. 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.

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SOURCE: Orosur Mining Inc