The Brucejack area is on the eastern limb of the northerly trending McTagg anticlinorium, a regional scale, mid-Cretaceous structural culmination in the western Skeena fold belt.

The Brucejack property which contains the Valley of Kings zone is underlain by volcano-sedimentary rocks of the Stuhini Group (Upper Triassic) that are unconformably overlain by the Lower Jurasssic Hazleton Group and Middle to Upper Jurassic Bowser Lake Group cover rocks. These rocks are cut by the Brucejack fault, which is interpreted to have had a long history of reactivation. Alteration is mainly pervasive quartz-sericite-pyrite replacement in zones several hundred metres wide and several kilometres long. Most of the five mineral resources (West Zone (104B 193), Valley of the Kings (104B 199), Bridge Zone (104B 612), Gossan Hill (104B 190), and Shore Zone (104B 189)) are in the intensely altered zones and associated with vein-stockworks. High-grade zones are either on the margins or contained in a zone of bulk low-grade mineralization up to several grams per tonne gold. Bulk low-grade mineralization tends to be associated with disseminated anhedral pyrite. High grade gold-silver electrum mineralization is hosted in deformed transitional epithermal stockwork veins up stratigraphy from several large and slightly older porphyry deposits; the multiphase Early Jurassic Mitchell intrusions.

At the Valley of Kings (VOK) deposit, surface mapping and Pretivm Resource's extensive drilling defined a number of lithologic contacts which outline a broad syncline in which fragmental volcanic and clastic sedimentary rocks, along with minor flows of Upper Triassic to Lower Jurassic age appear to plunge moderately to the east. Variably altered hornblende feldspar phyric volcanic rocks of intermediate composition (most probably latite) are interpreted as forming the youngest rocks of the sequence at the VOK, and are seen outcropping to the south, west and to the north-west, and broadly correlative coarse pyroclastic rocks, including common lapilli tuff and tuff breccia may occupy the core of the VOK syncline. Underlying these are interbedded volcanic-derived immature sedimentary rocks, including common pebble and cobble conglomerate and pebbly sandstone. The sedimentary sequence is considered correlative with the basal Jack Formation of the Hazelton Group. Thin Upper Triassic(?) rhyolite flows, as well as local siliceous exhalites have been mapped on surface and logged in drill core in the vicinity of this contact. Beneath the rhyolite is a relatively thick and generally poorly stratified sequence of fine-grained concretion-bearing mudstone and siltstone with locally interbedded sandstone and pebble conglomerate. In the vicinity of VOK, contacts and even the unconformity appear to have been folded, commonly tightly. The contacts outline a complex east-plunging syncline with a flanking east-plunging cuspate anticline to the south and what appears to be an even more complex antiformal structure to the north. The northern limb of the fold opens to the northeast, where it may eventually reverse trend and continue to the northwest into the area between the West Zone and Gossan Hill. Much of the complexity may reflect that the east-west trending folds are refolding an earlier northeast-trending set of folds, but some of the complexity may also reflect the fact that there may have been relief on the unconformity surface.

High-grade gold and silver mineralization within the VOK Zone occurs as electrum, and it is generally hosted within quartz-carbonate and quartz-adularia veins and vein stockworks. While quartz veining and stockworks are common throughout the zone, the majority of gold intersections are confined to a 75 to 100 m wide zone which closely parallels the axis of the syncline. Within that zone, the mineralization appears to have been concentrated in localized fold noses and along geologic contacts, in particular along the contact between the overlying pyroclastic rocks and the underlying conglomerate, as well as locally along the margins of flow-banded rhyolite. Significant intervals of gold mineralization, including several occurrences of visible gold, have been intersected to the west of the VOK, at the Waterloo Zone, suggesting the possibility that the mineralized trend may extend farther west, across the Brucejack fault.

Gold:silver ratios within the VOK Zone are typically 2:1 or higher, but may vary greatly. This may be due in part to the relative abundance of electrum in the deposit, or to the local presence of silver sulphide minerals. Additional precious metal-bearing minerals found in the VOK, typically in trace quantities, include silver sulphides, acanthite, pyargyrite and tetrahedrite, while base metal-bearing sulphides include sphalerite and galena.

The VOK mineralized zone trends approximately west-northwest to east-southeast. Its orientation mirrors that of Electrum Ridge, a pronounced topographic feature near the southern margin of the zone, and drilling to date has extended its strike to over 450 meters. The zone is up to 150 meters wide and is bound to the west by the Brucejack fault but remains open at depth and to the east.

As it is elsewhere on the property, alteration at the Valley of the Kings zone is believed to be Early Jurassic in age. It consists dominantly of quartz-sericite-pyrite, with lesser sericite-chlorite. The most pervasive of the intense alteration is observed within the sedimentary and fragmental volcanic rocks. Within them, the abundance of phyllosilicate minerals, and the subsequent deformational overprint, has resulted in the development of a pervasive east-west trending and steeply dipping foliation. In the VOK, the foliation appears to be axial planar to the main fold trend.

The first diamond drill program at VOK was conducted by Silver Standard Resources (SSR) in 2009, which intersected a number of intervals of high-grade gold mineralization, including one of 16,948 grams per tonne gold and 8,695 grams per tonne silver over 1.5 metres in hole SU-012 and two additional 1.5 metres intersections between 40 and 80 grams per tonne gold in that hole and four more spread between holes SU-034 and 035 (Technical Report for Pretium Resource, January 12, 2012). Additional diamond drilling in 2010 included 12 drill holes totalling 4,871 meters. The results of this program were considered very encouraging, with five of the holes intersecting high-grade gold mineralization (Technical Report for Pretium Resource, January 12, 2012). Pretivm’s drilling at the VOK in 2011 totalled 101 holes and more than 43,100 meters.

Valley of Kings Mineral Resource estimate based on a cut-off grade of 5 grams per tonne gold equivalent is 9.9 million tonnes grading 16.2 grams per tonne gold and 14.1 grams per tonne silver in the Indicated category; and 4.6 million tonnes grading 35.0 grams per tonne gold and 13.3 grams per tonne silver in the Inferred category (Technical Report for Pretium Resource, September 18, 2012).

The Valley of the Kings zone (VOK) is approximately 500 metres south of the West Zone, and was initially explored by Esso Minerals in 1981. It was later explored by Newhawk Gold Mines (NGM) and named the Spine zone, due to the presence of small, silicified and resistant relatively high-standing stockworks that outcrop in several places along its trend. This particular stockwork is topographically prominent but generally quite barren. The early exploration programs included surface grab and trench sampling, with many samples yielding weak to moderately anomalous gold values, but one outstanding sample which assayed 7 grams per tonne gold (Technical Report for Pretium Resource, January 12, 2012).

Mineral Reserves as of December 2016 for the Valley of Kings are 3.3 million tonnes grading 14.5 grams per tonne gold and 12.9 grams per tonne silver in the Proven reserves category; and 12.3 million tonnes grading 16.5 grams per tonne gold and 11.3 grams per tonne silver in the Probable Reserves category (News release dated December 14, Pretium Resources). For the West zone (104B 193) there are 1.4 million tonnes grading 7.2 grams per tonne gold and 383 grams per tonne silver in the Proven Reserves category; and 1.5 million tonnes grading 6.5 grams per tonne gold and 181 grams per tonne silver in the Probable reserves category (Feasibility Study and Technical Report Update on the Brucejack Project, dated June 19, 2014).

Combined, Proven plus Probable reserves for the VOK and the West zone remain unchanged from the 2014 feasibility study at 18.5 million tonnes grading 14.6 grams per tonne gold and 53.5 grams per tonne silver (2016 Exploration Overview, page 155).

The drill program increased Measured resources for the VOK by 58 per cent. Measured plus Indicated resources for the VOK zone now total 16.4 million tonnes grading 17.2 grams per tonne gold and 15.0 grams per tonne silver. Additional Inferred resources total 4.6 million tonnes grading 21.0 grams per tonne gold and 26.9 grams per tonne silver (2016 Exploration Overview, page 155).

In January 2019, an updated mineral resource for the Valley of the Kings (VOK) deposit was reported at 13.7 million tonnes measured and indicated grading 17.15 grams per tonne gold and 15.5 grams per tonne silver with an additional 3.8 million tonnes inferred grading 17.7 grams per tonne gold and 19.4 grams per tonne silver, using a 5 grams per tonne gold equivalent cut-off grade (Jones, I. (2019-04-04): Technical Report on the Brucejack Gold Mine). Also, at this time mineral reserves were reported at 13.1 million tonnes proven and probable grading 13.8 grams per tonne gold and 10.7 grams per tonne silver (Jones, I. (2019-04-04): Technical Report on the Brucejack Gold Mine).

In 2019, Pretium Resources Inc. completed six underground diamond drill holes, totalling 8810 metres, which demonstrated the continuity of gold mineralization below the Valley of the Kings (MINFILE 104B 199), with visible gold mineralization observed more than 500 metres below the current Valley of the Kings resource.

In early 2020, Pretium Resources Inc. reported an updated mineral resource and mineral reserve for the Bruce Jack project (West and Valley of Kings [MINFILE 104B 199] zones) of 23 200 000 tonnes grading 10.1 grams per tonne gold and 65.5 grams per tonne silver measured and indicated with an additional 9 400 000 tonnes grading 10.3 grams per tonne gold and 44.3 grams per tonne silver using a 3.5 grams per tonne gold cut-off grade, whereas mineral reserves were reported at 15 700 000 tonnes proven and probable grading 8.4 grams per tonne gold and 59.6 grams per tonne silver (Pretium Resources Inc. [2020-03-09]: Technical Report on the Brucejack Gold Mine, Northwest British Columbia).

Also refer to West (104B 193) for details of related mineralization and an up-to-date common work history, including reserves and resources.