Saturday, September 26, 2026
MiningNewsTerminal
Saturday, September 26, 2026 Admin

OGC.TO ·

OceanaGold Extends High-Grade Mineralization at Wharekirauponga and Receives Draft Decision and Conditions to Approve the Waihi North Project

Drill Results

1

www.oceanagold.com

November 25, 2025 News Release

OceanaGold Extends High-Grade Mineralization at Wharekirauponga

and Receives Draft Decision and Conditions to Approve the Waihi

North Project

(VANCOUVER, BC ) OceanaGold Corporation (TSX: OGC ) (OTCQX: OCANF) ("OceanaGold" or the

"Company") announces results from ten drill holes from the ongoing exploration and resource conversion

program at Wharekirauponga, located approximately 10 kilometres (“km”) to the north of the Company’s

Waihi operation in New Zealand.

OceanaGold is also pleased to announce that on November 25, 2025, the Expert Panel appointed by the

New Zealand government to consider permitting of the Waihi North Project (“WNP”) under the Fast-track

Approvals Act has released a draft decision and conditions indicating a provisional intention to approve the

project. The draft decision and conditions remain subject to a further comment period, with a final decision

expected by year-end 2025.

Wharekirauponga Drilling Highlights (estimated true width):

• 13.9 m @ 25.8 g/t Au from 466.8 m, EG vein (WKP137A)

• 7.4 m @ 5.3 g/t Au from 396.0 m, EG HWS vein (WKP137A)

• 1.8 m @ 108.1 g/t Au from 514.7 m, EG vein (WKP124J)

• 2.5 m @ 17.0 g/t Au from 530.3 m, EG FW vein (WKP124J)

• 3.2 m @ 19.7 g/t Au from 532.6 m, EG vein (WKP124K)

• 1.5 m @ 28.8 g/t Au from 474.4 m, EG HW vein (WKP124K)

• 5.6 m @ 6.9 g/t Au from 534.2 m, EG vein (WKP124L)

Gerard Bond, President and CEO of OceanaGold, said “ We are excited about today’s drill results from

Wharekirauponga that extend the high-grade mineralization at the southern boundary of the resource, as

demonstrated by the fantastic high-grade intercepts received by drill hole WKP137A. With more follow-up

drilling planned, I am very pleased with the value and return on investment that we continue to achieve

through exploration, as this deposit continues to grow.

2

www.oceanagold.com

We are also encouraged by the Expert Panel’s release of a draft decision and conditions indicating the

provisional intention to grant approvals for the Waihi North Project through the Fast -track Approvals Act.

We look forward to continuing our engagement with participants in the approvals process and progressing

through this next stage of the application to move towards the receipt of a final decision by the end of the

year. We intend to safely and responsibly develop the Waihi North Project which extends the mine life of

the Waihi operation well into the future, while generating strong returns for our shareholders and bringing

wider economic benefits for the local communities and for New Zealand.”

Drill results can be viewed in 3D using VRIFY at the following link:

https://vrify.com/meetings/recordings/1ec83dd5-7af1-41de-b60b-4cedf4d94ffc

VRIFY note: Drill results reflect only those set forth in OceanaGold’s press release dated November 25, 2025, and do not include all

historical results except those relevant to the current Wharekirauponga exploration target.

Wharekirauponga Drill Results Overview

East Graben (“EG”) Vein

Since the June 25, 2025 news release, a total of ten drill holes have been completed and results returned

from the EG, hanging wall (“HW”) and footwall (“FW”) veins, collectively referred to as the “EG vein zone”

(Figure 1). Drilling results have further extended the known limits of the mineralized EG vein 135 m to the

south (definition) and improved confidence in the potential for resource (conversion). These results continue

to demonstrate the significant potential to expand the mineral resource associate d with the EG vein zone.

Drilling from drill site 9 included the high -grade EG vein intercept from WKP137A (13.9 m @ 25.8 g/t Au),

extending the high-grade mineralization at the southern end of the resource. This result is supported by

previous intercepts WKP135 (6.3 m @ 8.7 g/t Au , released March 2025), WKP137 (4.0 m @ 43.8 g/t Au ,

released June 2025) and WKP134A (7.7 m @ 11.4 g/t Au, released November 2024) defining a new high-

grade zone on the southern boundary of the existing resource, which remains open to the south with

significant growth potential.

To further test this, step out hole WKP140A at the southern-most trace of drilling returned an intercept of

2.6 m @ 0.6 g/t, confirming the continuation of the EG vein 135 m to the south of previously reported hole

WKP139 (2.9 m @ 0.5 g/t Au , released June 2025). The continuity of veining demonstrated by WKP140A

supports growth of the total known strike length from 1.4 km to 1.5 km and this remains open to the north

and south.

Drill site 1 results include WKP143, completed down dip on the EG vein , returning 2.3 m @ 4.6 g/t Au ,

similar to neighbouring holes, extending mineralization.

3

www.oceanagold.com

At drill site 8, five new directional holes have been completed from the WKP124 parent hole , which have

infilled and tested the extents of the mineralization on the EG vein structure . Conversion drilling highlights

include the high-grade intersection received in hole WKP124J with 1.8 m @ 108.1 g/t Au (EG vein). Drill

hole intersections across the EG vein in holes WKP124K (3.2 m @ 19.7 g/t Au) and WKP124L (5.6 m @

6.9 g/t Au) met expectations and increased resource confidence. Drill holes WKP124H (NSR) and WKP124I

(NSR) defined the upper limit of the EG vein at this location (Figure 2).

Hanging Wall and Footwall Veins

Notably, the HW and FW vein structures that lie immediately to the east and west respectively of the EG

vein zone also yielded strong results . Drill hole WKP137A returned an intercept of 7.4 m @ 5.3 g/t Au on

the EG hanging wall splay (“HWS”), which extends the known mineralization on this structure, parallel to

extensions on the EG vein, with other previously reported surrounding intercepts including WKP135 (1.7 m

@ 24.6 g/t Au, released March 2025), WKP134A (2.3 m @ 16.0 g/t Au, released March 2025) and WKP137

(5.9 m @ 14.7 g/t Au, released June 2025) (Figure 3).

High-grade Au was intersected across several other EG HW and FW structures including 2.5 m @ 17.0 g/t

Au and 2.4 m @ 10.4 g/t Au from separate FW veins in drill hole WKP124J and 1.5 m @ 28.8 g/t Au from

a HW vein in WKP124 K, continuing to demonstrate the potential for additional resource growth at

Wharekirauponga outside of the main EG vein structure.

4

www.oceanagold.com

Figure 1: Wharekirauponga plan view of geology and drill traces highlighting the EG vein zone, T-Stream vein, and

Western veins, and drill platform locations

5

www.oceanagold.com

Figure 2: Long section of the EG vein with geology and drill intercepts (blue font = new holes)

Figure 3: Long section of the EG HWS vein with geology and drill intercepts (blue font = new holes)

Wharekirauponga Exploration Program

Exploration for the remainder of the 2025 program will continue to target resource growth on the EG vein

zone from drill sites 8 and 9. In October, the Company received permi ts for two additional exploration drill

sites. The Fast -track application includes a further increase in the number of exploration drill sites,

expanding the program by 8 new sites (inclusive of two new sites added in October) , as well as doubling

the drilling effort, with up to 6 rigs operating at any one time, from the currently permitted 3 rigs. The doubling

of the exploration drill sites and drill rigs will further accelerate both definition and conversion drilling at

Wharekirauponga in 2026 and beyond.

6

www.oceanagold.com

Table 1: Wharekirauponga drill intersections subsequent to the June 25, 2025, results update

Drill Hole

ID

From

(m)

To

(m)

True

width

(m)

Au

(g/t)

Ag

(g/t) Vein Activity

WKP124H 520.5 521.0 0.4 NSR EG Vein Definition

WKP124I 520.2 520.5 0.2 NSR EG Vein Conversion

WKP124J 514.7 516.9 1.8 108.1 71.9 EG Vein Conversion

WKP124J 530.3 533.7 2.5 17.0 16.1 EG FW Vein Conversion

WKP124J 577.1 580.2 2.4 10.4 18.4 EG FW Vein Conversion

WKP124K 474.4 476.4 1.5 28.8 30.7 EG HW Vein Conversion

WKP124K 532.6 537.1 3.2 19.7 11.8 EG Vein Conversion

WKP124K 585.4 586.5 0.8 16.3 9.3 EG FW Vein Conversion

WKP124L 534.2 542.9 5.6 6.9 5.3 EG Vein Conversion

WKP124L 626.5 628.9 1.4 8.3 12.1 EG FW Vein Conversion

WKP137A 396.0 404.2 7.4 5.3 5.7 EG HWS Vein Definition

WKP137A 417.6 420.7 2.8 7.0 6.1 EG HW Vein Definition

WKP137A 427.9 433.3 4.7 2.3 1.9 EG HW Vein Definition

WKP137A 439.3 440.1 0.6 33.4 20.8 EG HW Vein Definition

WKP137A 466.8 481.2 13.9 25.8 18.9 EG Vein Definition

WKP140 Hole abandoned prior to reaching EG vein target

WKP140A 543.8 547.0 2.6 0.6 3.3 EG Vein Growth

WKP141 220.5 222.4 1.5 10.2 35.3 EG HW Vein Definition

WKP141 248.5 248.9 0.3 48.9 31.5 EG HW Vein Definition

WKP141 376.3 378.0 1.6 1.7 14.9 EG Vein Definition

WKP141 472.0 476.8 4.2 4.4 24.4 EG FW Vein Definition

WKP142 398.3 401.0 2.4 1.5 14.2 EG Vein Definition

WKP143 467.8 470.5 2.3 4.6 11.5 EG Vein Definition

Notes:

“Growth” intercepts are associated with early-stage exploration drilling, “Definition” drilling intercepts are intercepts outside

the current resource model shell directed at defining mineralization to an Inferred Resource category and “Conversion”

drilling are intercepts converting Inferred Resources to Indicated Resources category. NSR = No Significant Result.

Waihi North Project Fast-track Approval and Early Works Activities Update

OceanaGold is encouraged by the Expert Panel’s release of a draft decision and conditions indicating a

provisional intention to grant approvals for the WNP through the Fast-track Approvals Act. It is important to

note that at this stage, a final decision has not yet been reached.

The Expert Panel will now invite comment on the proposed conditions of consent from relevant parties. The

Company will then have a chance to review and respond to these comments .

The Expert Panel’s final decision on the application is expected in mid-December 2025.

7

www.oceanagold.com

The Company also continues to advance early works, design and project activities at WNP, including

construction of the services trench and expansion of the water treatment plant, and expects to spend $45

million in capital in 2025 on these activities . The construction o f the 5 km services tren ch that will convey

power, water and communications from the existing Waihi operations to the Willows surface facilities area

commenced in the third quarter of 2025. Civil works and fabrication have also commenced at the expanded

water treatment plant site and are progressing well , with both deliverables planned for completion by the

second quarter of 2026.

Figures 4-5: Services trench construction – October 2025

Figure 6: Water treatment plant expansion – October 2025

For further information relating to drill hole data please refer to the Company’s website at

https://investors.oceanagold.com/additional-drillhole-data.

8

www.oceanagold.com

About OceanaGold

OceanaGold is a growing intermediate gold and copper producer committed to safely and responsibly

maximizing the generation of Free Cash Flow from our operations and delivering strong returns for our

shareholders. We have a portfolio of four operating mines: the wholly-owned Haile Gold Mine in the United

States of America; the wholly-owned Macraes and Waihi operations in New Zealand ; and the 80%-owned

Didipio Mine in the Philippines.

For further information please contact:

Investor Relations:

Haley Mayers, VP, Investor Relations

Tel: +1 604-678-4097

[email protected]

Valerie Burns, Manager, Investor Relations

Tel: +1 604-235-0742

[email protected]

Media Relations:

Louise Burgess, VP, Communications

Tel: +1 604-403-2019

[email protected]

Qualified Person Statement

The scientific and technical information relating to Waihi exploration results in this press release has been

reviewed and approved by Mr. Leroy Crawford-Flett, a Chartered Professional Member of the Australasian

Institute of Mining and Metallurgy, a quali fied person under National Instrument 43 -101 – Standards of

Disclosure for Mineral Projects of the Canadian Securities Administrators (“NI 43-101”). Mr. Crawford-Flett

is the Exploration & Geology Manager of Waihi Operation.

Quality Assurance and Quality Control (“QA/QC”)

All exploration samples are assayed for gold by 30g fire assay with AAS finish. Since mid -2022, drill core

sample intervals where visible electrum is logged are followed up by a subsequent screen fire assay after

the routine 30g fire assay. Core samples were prepared and analyzed at SGS Waihi NZ Ltd (Au by 30g fire

assay and Ag by aqua regia digest and 0.3gm AAS finish . Samples post April 2024 with Ag, As, Sb. Hg

and S by ICP-MS after DIG12R Digest). Selected pulps are periodically sent to ALS in Brisbane for a 4 -

acid digestion and 42 or 48 element ICP geochemical analysis.

Quality of exploration assay results has been monitored in the following areas:

• Sample preparation at the SGS Waihi and Westport labs through sieving of jaw crush and pulp

products;