Impact Minerals Ltd Annual Report 2022 31 At Silica Hill the maiden Inferred Resource at a 50 g/t silver cut-off is: SILICA HILL Resource Classification Cut-off 50 g/t silver Lode Tonnes (t) Silver (g/t) Contained silver (oz) Gold (g/t) Contained gold (oz) Inferred North 397,000 89 1,136,000 1 12,900 Inferred South 313,000 87 871,000 0.5 5,100 TOTAL 710,000 88 2,007,000 0.8 18,000 The resources are open along trend and at depth and extensive further resource definition and extensional drilling is required to follow up key intercepts at Main Shaft, Commonwealth South and Silica Hill. ABOUT THE MINERAL RESOURCE ESTIMATE AT COMMONWEALTH The mineralisation at Commonwealth-Main Shaft is typical of a volcanogenic massive sulphide (VMS) type system, containing high grade gold, silver, zinc, lead and copper mineralisation which occurs at the upper contact of a porphyritic rhyolite with the overlying volcanic sedimentary rocks. The Commonwealth Resource strike length is 400 m and it is open along trend in particular to the south. The mineralisation has been defined to a maximum depth of 150 m and is still open. The total number of holes drilled at the Commonwealth Project by Impact and previous explorers in a number of separate drill campaigns is 132. Of these holes, 66 were used in the estimation to define a wireframe model. Impact has twinned some of the historical higher grade intersections and these have largely confirmed the grades and widths. The average depth of the drill holes is 52 metres highlighting the shallow nature of the deposit. Holes were drilled with a variety of azimuths and dips to ensure the mineralised units were intersected at optimal angles. Quality control measures employed by Impact included the use of certified standards (1% of total sample population), field duplicates (2% of total sample population) and blanks (2% of total sample population). No previous quality assurance/quality control (QAQC) has been carried out at the Commonwealth Project. Analysis of the standards and blanks showed acceptable to good levels of accuracy in the assaying and little contamination. The duplicate samples matched the originals with a high degree of precision. The drill hole database was reviewed and validated. The top cuts used were gold 30 ppm, silver 500 ppm, copper 1% and zinc 10%. Three-dimensional solid wireframes were constructed from sectional interpretations of the mineralisation using a nominal 0.5 g/t gold cut-off grade. Drill hole intercepts were composited downhole to 1 m lengths and gold, silver, copper, zinc, lead and arsenic grade estimation was carried out using ordinary kriging with hard boundaries. Three search passes, with increasing search distances and decreasing minimum sample numbers, were employed to fully inform the model. All elements filled all cells in the first three search passes. The Commonwealth Mineral Resource estimate has been classified as an Inferred Mineral Resource in accordance with the guidelines of the Australasian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves (the JORC Code, 2012). Mineral Resources have been classified on the basis of confidence in geological and grade continuity, geological modelling confidence, grade continuity and limited QAQC. No Measured or Indicated Mineral Resources have been defined. The Mineral Resource estimate for the Commonwealth Project has been reported above a 0.5 ppm gold cut-off grade. The estimate has been depleted for previous historic mining. Review of Operations continued
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