Feasibility Study and Technical Report - Pretivm

more distal (i.e. down temperature) from the intrusive stock/dyke/sill body than the KSMand Snowfield deposits.Thermal perturbations associated with pulsing in the porphyry system would likely haveresulted in a succession of alteration and mineralization imprints and overprints withinsuch a transitional and active environment and possibly induced upgrading and zonationof the precious metal mineralization, especially considering constraints on gold mobilityin this environment (Gammons and Williams-Jones 1997).More than 40 gossanous zones of gold, silver, copper, and molybdenum mineralizationhave been identified along the length of the arcuate band of altered rocks as a result ofperiodic exploration over the past several decades (Figure 7.7). A subset of these zoneswas selected for additional follow-up exploration in 2011 by Pretivm (Figure 7.8). A totalof five zones were modelled for mineral resource estimation: Bridge Zone, VOK, WestZone, Gossan Hill, and Shore Zone. These zones range from deformed high-grade goldrich,silver-poor zones such as VOK, through deformed high-grade gold-silver zones likeWest Zone, to high-tonnage but relatively low-grade zones like the Bridge Zone. Recentgeological interpretation has shown that the area previously covered by Galena Hill isactually an extension of VOK and this area has now been incorporated into VOK.BRIDGE ZONEThe Bridge Zone is located about 1,500 m south of the West Zone and is centred on a3 ha nunatak surrounded by ice of the eastern arm of the Sulphurets Glacier. Goldmineralization at the Bridge Zone is hosted by plagioclase-hornblende phyric volcanicrocks that are moderately to strongly sericite-chlorite altered, with disseminated andstringer pyrite making up a few percent of the rock by volume. Mineralization occurs bothin low-grade bulk tonnage associated with the altered host rocks, and in deformed quartzvein and vein stockwork associated moderate to high-grade styles. The moderate- tohigh-grade mineralization is generally associated with east-west trending quartz vein andvein stockworks that dip steeply to the north.Quartz ± chlorite ± sericite veins, ranging from 20 cm to 200 cm in thickness, are fairlycommon and contain minor to trace amounts of pyrite, sphalerite, galena, molybdenite,and an unknown dark grey, possibly silver-bearing sulphosalt (or salts). Some of theveins contain appreciable concentrations of molybdenum and rhenium, with themolybdenum/rhenium ratio similar to that at Pretivm’s Snowfield Deposit.The pervasive nature of the mineralization in the Bridge Zone, the association of thismineralization with molybdenum and rhenium, and the spatial proximity of the intenselyhydrothermally altered and mineralized southern limb of the VOK syncline (immediatelyto the north of the Bridge Zone), suggests that the Bridge Zone rocks were relativelyproximal to an intrusive body (stock/sill/dyke/other narrow apophysis) of the mineralizingporphyry system.Pretium Resources Inc. 7-19 1291990200-REP-R0012-02Feasibility Study and Technical Report on the BrucejackProject, Stewart, BC