OceanaGold Corporation (TSX: OGC) (OTCQX: OCANF) announces results from seven drill holes from the ongoing exploration and resource conversion program at Wharekirauponga, located approximately 10 kilometres to the north of the Company’s Waihi operation in New Zealand.

Drilling Highlights (estimated true width):

• 4.0 m @ 43.8 g/t Au from 467.5 m, EG vein (WKP137)
• 8.1 m @ 11.8 g/t Au from 646.4 m, EG FW vein (WKP124G)
• 5.9 m @ 14.7 g/t Au from 398.6 m, EG HWS vein (WKP137)
• 4.1 m @ 11.5 g/t Au from 532.4 m, EG vein (WKP124E)
• 6.1 m @ 5.6 g/t Au from 446.9 m, EG vein (WKP138)

Gerard Bond, President and CEO of OceanaGold, said “Today’s results further reinforce the tremendous growth potential we have at Wharekirauponga. Gold mineralization continues to increase in scale and is now defined over a strike length of more than 1.4 km, including a further 240 metres to the south of previously intercepted mineralization, and remains open in all directions. Drilling is ongoing with three rigs targeting additional step outs, resource extension, resource conversion and geotechnical drilling for development of the Wharekirauponga underground mine, as we continue to invest in this exciting orebody. The expansion of Wharekirauponga underscores its position as a key asset in our portfolio and highlights the exciting role it will play in shaping the future of OceanaGold and shareholder returns.”

Results can be viewed in 3D using VRIFY at the following link:
https://vrify.com/meetings/recordings/549f06b2-198b-4d9a-a72f-cdfbec316c14

VRIFY note: Drill results reflect only those set forth in OceanaGold’s press release dated June 25, 2025, and do not include all historical results except those relevant to the current Wharekirauponga exploration target.

Wharekirauponga Drill Results Overview

EG Vein 

Since the March 4, 2025 news release, a total of eight drill holes have been completed across the EG, hanging wall, and footwall veins, collectively referred to as the “EG vein zone”, extending the known strike of mineralization to ~1.4 km. Results for seven of these holes have been received and continue to demonstrate the significant potential to expand the mineral resource associated with the EG vein zone. Drilling completed includes two exploration step-out holes from the most southern drill site, drill site 9, one resource conversion hole from drill site 8 and five resource extension holes from drill sites 1, 8 and 9 (Figure 1).

Two widely spaced exploration step-out holes, WKP138 (6.1 m @ 5.6 g/t Au) and WKP139 (2.9 m @ 0.5 g/t Au), have now extended mineralization a further 240 metres south of the current Inferred Resource and previously intercepted mineralization (WKP135 6.3 m @ 8.7 g/t Au, released March 2025). Another significant step-out hole (WKP140) is in progress and testing ~400 metres south of WKP135 (Figure 2). Importantly, the Hanging Wall Splay is well developed and mineralized (3.3 m @ 4.5 g/t Au) indicating significant potential remains in this part of the system for growth on both structures (more detail on the HW and FW structures below).

Resource conversion hole WKP124E intersected high-grade mineralization in the EG vein with 4.1 m @ 11.5 g/t Au, increasing confidence in the high-grade southern shoot (Table 1, Figures 2 and 3).

Five holes tested immediate extensions to high-grade mineralization, including WKP137 which intersected excellent grade and width (4.0 m @ 43.8 g/t Au) to the south at lower levels. Holes WKP129B and WKP129C successfully drilled across the projection of the EG vein structure at the top of the currently defined high-grade shoot intersecting minor quartz and fault structures, with hole WKP129B returning 2.8 m @ 2.6 g/t Au.

Hanging Wall and Footwall Veins

Notably, the HW and FW vein structures associated with the EG vein zone also yielded strong results and have expanded known mineralization. WKP139 confirmed the extension of the HWS and returned 3.3 m @ 4.5 g/t Au along with 5.9 m @ 14.7 g/t Au in WKP137 (Figure 4). The latter result being ~40 metres up dip of other high-grade intersections, including holes WKP134A (2.3 m @ 16.0 g/t Au, released November 2024) and WKP135 (1.7 m @ 24.6 g/t Au, released March 2025).

In the FW zone, a previously unmodelled vein has been defined in WKP124G (8.1 m @ 11.8 g/t Au), 65 metres along strike from WKP124D (3.8 m @ 21.4 g/t Au, released in November 2024).

As we have experienced at Martha Underground, significant opportunity remains with further drilling for up-plunge, down-plunge and along-strike extensions on these and other attendant HW and FW veins.

2025 Wharekirauponga Exploration Program

Exploration drilling for the remainder of the 2025 program will continue to target resource growth on the EG vein zone from drill sites 1, 8 and 9, testing beyond the current southern extent of drilling, and up-dip of both current and future extensions in the south. The Fast-track application includes an increase in the number of exploration drill sites, expanding the programme by 8 new sites, as well as doubling the rate of drilling, with up to 6 rigs operating at any one time. This will further accelerate both growth and conversion drilling at Wharekirauponga. The EG vein zone remains the primary, near-term target for drilling in 2025 with approximately 5,000 metres remaining to be drilled this year.

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 (CNW Group/OceanaGold Corporation)

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

Figure 3: Inset image from Figure 2. Long section of the EG vein with geology and drill intercepts (blue font = new holes) (CNW Group/OceanaGold Corporation)

Figure 4: Long section of the EG HWS vein with geology and drill intercepts (blue font = new holes) (CNW Group/OceanaGold Corporation)

Table 1: Wharekirauponga drill intersections subsequent to the March 4, 2025, results update

For further information relating to drill hole data please refer to the Company’s website at https://investors.oceanagold.com/additional-drillhole-data.

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 Haile Gold Mine in the United States of America; the Didipio Mine in the Philippines; and the Macraes and Waihi operations in New Zealand.