Supporting Technical Assessments

WKP PFS – Geotechnical Section Approved by: Approval Date: TBA OceanaGold PEX-000-PLN-046-A Page 19 of 22 Figure 15: MAP3D mine design and model geometry Figure 15 shows the overall mine design and model geometry. The surface was set at the 220 RL. The MOX, POX, and SLOX zones ranged from the 220 RL to the 155 RL. The host rock below the 155 RL was set to the material properties of fresh rhyolite. The stopes and ore drives located below the 155 RL were set to the material properties of ore material. The UCS values for the rhyolite were based on the testing information from WKP68 from the Scoping Study. The latest lab results from E-Precision were not available when the model was run. Despite the relatively low UCS results from some of the samples tested in October 2020, the average UCS of 153 MPa for the rhyolite is likely to be in the ballpark (given the relationship between rock density and UCS discussed earlier in this report). Figure 16: Stress damage in the stopes and crown pillar at the end of life-of-mine Figure 16 shows the stress damage in the stopes and crown pillar at the end of life-of-mine. Apart from the isolated areas shown, there is not much stress damage.

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