G Mining Ventures Reports New High-Grade Discovery at Oko West and Extension of Mineralization at Gurupi

BROSSARD, QC, Sept. 9, 2025 /PRNewswire/ - G Mining Ventures Corp. ("GMIN" or the "Corporation") (TSX:GMIN, OTCQX:GMINF) is pleased to provide an exploration update, including significant exploration results from its Oko West Gold Project ("Oko West") in Guyana and its Gurupi Project ("Gurupi") in Brazil.

(All grade reported as grams per tonnes of gold "g/t Au" and length in meters "m".)              

Key Highlights at Oko West 

At Oko West, recent drilling guided by a newly developed Splay Model along the main mineralized zone have delivered high grade intercepts, confirming both near-mine growth and regional discovery potential (Figures 1 to 3; Table 1). Recent drilling has returned:

• The discovery of the second high grade plunge of mineralization beyond the current pit limits to the north at Oko West in Block 1 ("B1"), including:
  • 2.9 m at 37.85 g/t Au (OKWD25-518)
  • 21.0 m at 3.80 g/t Au (OKWR25-1839)
  • 14.0 m at 4.38 g/t Au (OKWD25-533)
  • 15.5 m at 3.53 g/t Au (OKWD25-533)
• Development of a mineralized Splay Model within the principal mineralized zone, capturing the structural complexity of the main shear system and delineating vectors for exploration potential beyond the current reserve pit. Results include:
  • 11.9 m at 5.26 g/t Au (OKWD25-545) 
  • 14.0 m at 1.10 g/t Au (OKWD25-516)

Key Highlights at Gurupi

Since acquiring Gurupi at the end of 2024, the Corporation has made progress in advancing permitting while restarted field exploration work to prepare for the launch a robust exploration drilling program across its highly prospective land package (Figures 5 to 7; Table 2). Key results from trenching include:

• Extension of the known mineralization 2 km north of Chega Tudo deposit at the Grodiocal target with trenches including:
  • 9.0 m at 3.52 g/t Au (GMAMT-25-008)
  • 3.0 m at 3.63 g/t Au (GMAMT-25-005)
  • 3.0 m at 2.09 g/t Au (GMAMT-25-001)
  • 7.0 m @ 0.97 g/t Au (GMAMT-25-005)
  • 5.0 m @ 0.89 g/t Au (GMAMT-25-001)
• Relaunch of regional exploration program at Gurupi with expected drilling in Q4-2025.

"Exploration at Oko West continues to expand our understanding of the deposit and reinforces the robust economics demonstrated in the Feasibility Study, while at Gurupi, trenching results validate near-surface mineralization, demonstrating the high prospectivity of the large land package" said Julie-Anaïs Debreil, Vice President Geology & Resources. "High-grade intercepts confirm Oko West's exceptional potential and support future mine life extensions. At Gurupi recent work provide the confidence to launch our first drill program later this year. Combined with Tocantinzinho's robust cash flow, our pipeline of high-quality projects firmly positions GMIN to become the next intermediate gold producer."

Oko West Project, Guyana

New Ore Shoot Discovery

Since the completion of Feasibility Study ("FS") drilling , the Corporation has completed an additional 9,968 m of core drilling focused on exploring mineralized extensions outside the known reserve. Results to date have led to the discovery of the second high grade plunge of mineralization beyond the current pit limits to the north (B1, Figure 1). This newly discovered plunge starts near surface and outside of the existing pit, and contains grades that could be easily integrated into the existing open pit and underground mine plan (Figure 2). This new ore shoot discovery demonstrates that the Oko West Deposit continues to grow.

Splay Model Success

Drilling also aimed to confirm a newly developed Splay Model, based on detailed structural observations (Figure 3). The Splays are smaller structures that branch off a main shear zone, acting like natural off-ramps that redirect stress and mineral-rich fluids into the surrounding rock. These offshoots can form highly prospective zones for exploration. The Splay Model integrates validated structural insights, providing a framework to better target mineralization occurring outside the main vein systems. The modelled veins present in the pit add mineralization to the model outlined in the FS, decreasing the strip ratio of the deposit during the mining phase.

The purpose of this model revision is to better target mineralization around the pit. This has proven to be successful with several veins demonstrating continuity outside of the known pit (Figure 3).

Highlights of intercepts include the following listed below, with details provided in Table 1.

• 11.9 m at 5.26 g/t Au (OKWD25-545, AU_2FW)
• 14.0 m at 1.10 g/t Au (OKWD25-516, ODZ)
• 7.0 m at 2.08 g/t Au (OKWD25-545, AU_3HW)
• 5.0 m at 2.22 g/t Au (OKWR25-1838, Splay_FW2) * reverse circulation ("RC") drilling hole
• 6.1 m at 1.73 g/t Au (OKWD25-528, CTZ)

Regional Exploration

As construction ramps up, exploration efforts will continue to pursue regional targets with a fly camp. The NW extension target located 10 km northwest of the Oko West deposit presents a strong soil anomaly. Early interpretations from trenching have revealed cross-cutting mineralized structures, dominated by extensional, NW-trending sulfide-rich quartz veins and conjugate NNE-oriented shear zones, suggesting a complex structural regime influencing fluid flow and mineral deposition. These structures are closely associated with the main foliation patterns within the volcano-sedimentary sequence and are further influenced by a broader granitoid intrusive system. A total of 6,300 m of trenching and reverse circulation drilling is planned, which may be followed by diamond drilling depending on success, to provide a better understanding of this mineralized system and help refine GMIN's interpretation (Figure 4).

Gurupi Project, Brazil

Since acquiring the Gurupi Project, GMIN has moved quickly to: consolidate historical datal reinitiate field work; conduct infill soil sampling and subsequent trenching in prospective areas; engage with various stakeholders; and restart the permitting processes. A recent court ruling annulled outdated licenses issued to a prior operator, opening the door for a renewed exploration and development strategy.

Gold mineralization in the Gurupi Belt is controlled by the Tentugal shear zone, a 15–30 km wide and ~120 km long sinistral strike-slip corridor, where deformation focused in carbonaceous schists and volcanic and volcanoclastic rocks (Figure 5). Gold in deposits along this trend is hosted in quartz–carbonate–sulfide veins and disseminated pyrite, with alteration marked by silicification, carbonatization, and sulfidation. Mineralization is consistent with classic orogenic gold systems.

Gurupi consists of 47 contiguous tenements covering ~1,900 km² along the Tentugal shear zone, with current mineral resources including 1.83 Moz of indicated resources (43.5 Mt at 1.31 g/t Au) and 0.77 Moz of inferred resources (18.5 Mt at 1.29 g/t Au), hosted in the Blanket, Contact (Cipoeiro area), Chega Tudo and Mandiocal (Chega Tudo area) deposits. These deposits offer strong expansion potential as limited drilling outside of the resource areas has been completed.

Infill soil sampling completed in 2025 have highlighted three main mineralized structures 2 km north of known mineralization at Mandiocal (Chega Tudo). Follow up trenching carried out over these anomalies has confirmed the district's exploration upside (Figure 6, Table 2).

Expanded 2025 Exploration Program

An expanded 2025 budget of USD $6–8 million has been approved (previously USD $2-4 million – see news release dated February 20, 2025), with the primary objective of testing the continuity at depth of the surface mineralized structure highlighted by soil and trenching at Grodiocal. A total of 10,000 m of RC drilling is currently planned, of which 7,500 m is expected to be completed by year-end. This will be complemented by regional soil sampling and trenching aimed at generating and advancing new targets.

This RC drilling is located outside of the claims subject to the past injunction as we expect the permitting process to be completed in Q1-2026 in these claims (Figure 7). Diamond drilling (DD) is planned with a total of 8,500 m focused on the Cipoiero extension. This program will commence soon after the receipt of all required permits. The long-term exploration strategy focuses on defining new deposits across this highly prospective property to drive significant resource growth.

Sampling and Quality Assurance/Quality Control ("QA/QC") Disclosure 

Oko West assay results are from core samples sent to Actlabs certified laboratory in Georgetown, Guyana for preparation and analysis utilizing both fire assay and ICP methods. For a complete description of Oko West's sample preparation, analytical methods and QA/QC procedures refer to the technical report with an effective date of April 28, 2025, entitled "Feasibility Study – NI 43-101 – Technical Report, Oko West Gold Project". 

Gurupi assay results are prepared at ALS Chemex in Parauapebas, Brazil, and analyzed at an accredited laboratory in Lima, Peru, using fire assay and Inductively Coupled Plasma ("ICP") methods. Standard preparation includes crushing to 70% passing 2 mm and pulverizing 250 g to 85% passing 75 μm. Gold assays are performed using a 30 g fire assay with atomic absorption finish, with samples returning >10 g/t Au re-assayed by fire assay with gravimetric finish. When visible gold is present, a 1 kg split is pulverized to 95% passing 106 μm and subjected to screen fire assay for coarse gold evaluation. Duplicate analyses are also completed for added quality control. For a complete description of Gurupi's sample preparation, analytical methods and QA/QC procedures refer to the technical report for the Gurupi project dated April 8, 2025 (effective date February 3, 2025), entitled "Mineral Resource Estimate NI43-101 Technical Report Gurupi Project".

The Corporation maintains a rigorous QA/QC program, including the routine insertion of certified standards, blanks, and field duplicates (approximately 10% of all samples). QA/QC results are closely monitored, and any failures are re-assayed to ensure the reliability of reported results.

Qualified Person ("QP")

The technical content of this press release has been reviewed by Julie-Anaïs Debreil, Vice President Geology & Resources of GMIN, a QP as defined in National Instrument NI 43-101 ("NI 43-101"), on behalf of the Corporation and has approved the technical disclosure contained in this news release.

About G Mining Ventures Corp.

G Mining Ventures Corp. is a mining company engaged in the acquisition, exploration and development of precious metal projects to capitalize on the value uplift from successful mine development. GMIN is well-positioned to grow into the next mid-tier precious metals producer by leveraging strong access to capital and proven development expertise. GMIN is currently anchored by the Tocantinzinho Mine ("TZ") in Brazil, supported by the Gurupi Project in Brazil and the Oko West Project in Guyana — all with significant exploration upside and located in mining-friendly jurisdictions. GMIN trades on the TSX under the symbol "GMIN".

Additional Information 

For further information on GMIN, please visit the website at www.gmin.gold. 

Cautionary Statement on Forward-Looking Information

All statements, other than statements of historical fact, contained in this press release constitute "forward-looking information" and "forward-looking statements" within the meaning of certain securities laws and are based on expectations and projections as of the date of this press release. Forward-looking statements contained in this press release include, without limitation, those related to (i) the confirmation of both near-mine growth (namely beyond the current reserve pit) and regional discovery potential at Oko West; (ii) the expected drilling at Gurupi in Q4-2025; (iii) the continuity of known mineralization along the main deformation zone beyond the Oko West pit limits; (iv) the construction ramping up at Oko West; (v) the strong exploration potential of the Blanket, Contact, Chega Tudo and Mandiocal deposits at Gurupi; and (vi) in general, the sections entitled "Oko West – Regional Exploration", "Gurupi – 2025 Exploration Program Increase" and "About G Mining Ventures Corp."; as well as the quoted comments of GMIN's Vice President, Geology & Resources.

Forward-looking statements are based on expectations, estimates and projections as of the time of this press release. Forward-looking statements are necessarily based upon a number of estimates and assumptions that, while considered reasonable by the Corporation as of the time of such statements, are inherently subject to significant business, economic and competitive uncertainties and contingencies. These estimates and assumptions may prove to be incorrect. Such assumptions include, without limitation, those relating to the price of gold and currency exchange rates, those relating to mineral reserves and resources as well as exploration targets, and those underlying the items listed in the above sections entitled "Oko West – Regional Exploration", "Gurupi – 2025 Exploration Program Increase" and "About G Mining Ventures Corp."

Many of these uncertainties and contingencies can directly or indirectly affect, and could cause, actual results to differ materially from those expressed or implied in any forward-looking statements. There can be no assurance that, notably but without limitation, (i) the Corporation will continue to advance permitting for Gurupi at same or better pace; (ii) the grade associated with Oko West's newly discovered plunge will be integrated to the existing (open pit and underground) mine plan; (iii) the offshoots stemming from Oko West's "Splay Model" will lead to highly prospective zones for exploration; (iv) ongoing exploration efforts at Oko West will lead to the identification of targets; (v) Gurupi will be a cornerstone asset in the Corporation's portfolio; (vi) the surface mineralized structure identified by soil sampling and trenching at Gurupi will continue at depth; (vii) the planned RC drilling, soil sampling and trenching at Gurupi for the remainder of 2025, will generate new exploration targets; (viii) the permitting process for diamond drilling at Gurupi will be completed in Q1-2026; (ix)  a formal construction for Oko West will be made in H2-2025, or at all; (iii) Guyana's regulatory environment will ensure timely decision-making allowing GMIN to achieve project milestones; * Oko West will advance responsibly and on schedule; (xi) GMIN will achieve its stated objectives for Oko West and Gurupi; or (xii) TZ and Oko West will grow GMIN into the next intermediate producer, as future events could differ materially from what is currently anticipated by the Corporation. In addition, there can be no assurance that Brazil and/or Guyana will remain mining friendly and prospective jurisdictions.

By their very nature, forward-looking statements involve inherent risks and uncertainties, both general and specific, and risks exist that estimates, forecasts, projections and other forward-looking statements will not be achieved or that assumptions do not reflect future experience. Forward-looking statements are provided for the purpose of providing information about management's expectations and plans relating to the future. Readers are cautioned not to place undue reliance on these forward-looking statements as a number of important risk factors and future events could cause the actual outcomes to differ materially from the beliefs, plans, objectives, expectations, anticipations, estimates, assumptions and intentions expressed in such forward-looking statements. All of the forward-looking statements made in this press release are qualified by these cautionary statements and those made in the Corporation's other filings with the securities regulators of Canada including, but not limited to, the cautionary statements made in the relevant sections of the Corporation's (i) Annual Information Form dated March 27, 2025, for the financial year ended December 31, 2024, and (ii) Management Discussion & Analysis. The Corporation cautions that the foregoing list of factors that may affect future results is not exhaustive, and new, unforeseeable risks may arise from time to time. The Corporation disclaims any intention or obligation to update or revise any forward-looking statements or to explain any material difference between subsequent actual events and such forward-looking statements, except to the extent required by applicable law.

Table 1 - Major Composites for Oko West Project

Table 2 - Major Composites Gurupi Trenches

Table 3 - Oko West Collar Coordinates

Table 4 - Gurupi Trenches Collar Coordinates

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