Supporting Technical Assessments

June 2022 G-14642.71-006-R-Rev0_FINAL vi 11.0 RECOMMENDATIONS....................................................................................................................................................................... 45 12.0 REFERENCES........................................................................................................................................................................................... 46 TABLES Table 1: Summary of in situ stress measurements at Trio Underground Mine at Waihi (provided to WSP by OGNZL)................................................................................................................................................................................................................. 8 Table 2: Summary of boreholes completed for Willows Road access tunnel. ..........................................................12 Table 3: Summary of rock sample test results. .....................................................................................................................................15 Table 4: Summary of geotechnical conditions from log of WNDD007 (Shaft #1 site). .................................... 16 Table 5: Hydraulic conductivity test results for Shaft #1 (WNDD007) (after GWS 2020). ..............................20 Table 6: Results from VW piezometers in WNDD007 (GWS 2020). ..................................................................................21 Table 7: Summary of findings from WNDD008 summarised from the GHD bore log. ...................................22 Table 8: Summary of geological conditions encountered in WNDD011.......................................................................27 Table 9: Summary of geological conditions encountered in WKP-P05D. ................................................................. 28 Table 10: Summary of laboratory testing carried out on samples from WKP-P05D......................................... 29 FIGURES Figure 1: Layout of the WUG project showing various elements referred to in this report. ..............................4 Figure 2: Geological map showing distribution of main lithologies. The pink unit 'Mci' comprises the various Miocene volcanic rock types encountered by the access tunnels. The yellow unit ‘mQm’ comprises younger alluvium. The general project corridor (ref Figure 1) is within the white rectangle. ......................................................................................................................................................................................................................................................... 5 Figure 3: Geomorphological map of the Willows farm area. .................................................................................................... 6 Figure 4: Principal stress orientations for Trio underground at Waihi (OGNZL). ....................................................... 9 Figure 5: Stress gradients determined for major, intermediate, minor and vertical stress components (OGNZL). ................................................................................................................................................................................................. 9 Figure 6: Long section along WUG Access Tunnel (Mitchell Daysh 2022). ................................................................. 10 Figure 7: Conceptual layout section of twin tunnel option (after Mitchell Daysh 2022). ..................................11 Figure 8: Borehole location plan from Willows Farm. ....................................................................................................................14 Figure 9: Autoclastic breccia andesite recovered from WNDD007. ................................................................................ 18 Figure 10: Porphyritic andesite recovered from WNDD007. ................................................................................................... 18 Figure 11: Clay altered sample from WNDD007. ................................................................................................................................ 19 Figure 12: Wellcad interpretation of discontinuities from WNDD007 between depths 32.79 m and 204.58 m (n=206). .........................................................................................................................................................................................................20 Figure 13: Lapilli tuff recovered from WNDD008. .............................................................................................................................24 Figure 14: Porphyritic andesite recovered from WNDD008. ...................................................................................................24

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