Feasibility Study and Technical Report - Pretivm

1.4 MINERAL RESOURCE ESTIMATESSnowden, in November 2012,completed a mineral resource estimate for VOK within theProject. The West Zone estimate remains unchanged from the April 2012 mineralresource estimate (Olssen and Jones 2012a). The new estimate is reported at a highgradecut-off for potential underground extraction.A threshold grade of 0.3 g/t Au was found to generally identify the broad zones ofmineralization in the drill cores at West Zone and VOK. At VOK, a 1 g/t Au to 3 g/t Authreshold grade was used together with Pretivm’s interpretation of the lithologicaldomains, to interpret high-grade corridors within the broader mineralized zones, anddefine a series of mineralized domains for estimation.High-grade gold mineralization at VOK occurs in a series of west-northwest trending subverticalcorridors of structurally reoriented vein stockworks and subordinate veinbreccias, hosted in a folded sequence of fine grained volcanic siltstone and sandstone,variably silicified polylithic volcanic conglomerate rocks, and fragmental volcanic rocks oflatitic composition, bounded by relatively massive porphyritic latite flows. Goldmineralization also appears to form a series of seemingly stratigraphy-parallel podswithin the steeply-dipping polylithic conglomerate and immediately overlying fragmentalvolcanic rocks in the core of the syncline. These pods appear to be spatially associatedwith intensely silicified zones that appear to have acted as pressure seals whichgenerated local overpressure conditions and subsequent depressurization by hydraulicand/or tectonic brecciation.All data was composited to the dominant sample length of 1.5 m prior to analysis andestimation. Statistical analysis of the gold and silver data was carried out by lithologicaldomain (at VOK) and mineralized domain. Review of the statistics indicated that thegrade distributions for the mineralization within the various volcanic and volcanosedimentarylithologies are very similar and as a result these were combined for analysis.All domains exhibit a strong positive skewness with high coefficient of variation andextreme outliers.Because of the extreme positive skew in the histograms of the gold and silver gradeswithin the high-grade domains, Snowden elected to use an indicator approach wherebythe proportion of high grade in a block was modelled, the grade of the high-grade portion,and the grade of the low-grade portion.The high-grade population, which contains a significant number of samples with extremegrades, required indicator kriging methods for grade estimation. The low-gradeestimation was estimated with ordinary kriging combined with top cut data.Density was estimated using simple kriging of specific gravity measurements provided byALS Minerals (ALS). As part of the 2012 drilling program, Pretivm selected a portion ofthe samples (207 samples) for core density measurements in addition to pulp specificgravity measurements to determine whether there is any impact on the density as aresult of porosity. The results of the comparison indicate that the core density is onPretium Resources Inc. 1-4 1291990200-REP-R0012-02Feasibility Study and Technical Report on the BrucejackProject, Stewart, BC