Nice easy to understand write up in BC Gov publication

High-grade gold-silver continues to be identified by

Pretium Resources Inc at their

Brucejack project located

approximately 65 km north of Stewart and 5 km west of

the Kerr Deposit of the KSM multi-deposit system. The

2012 drilling program was the largest in the region

totalling 105 769 m in 298 diamond drill holes. The

primary objective was to increase size and confidence of

the high-grade resource at the Valley of the Kings (VOK)

zone and gain a solid geological understanding of controls

on mineralization. At 12.5 m centers, (Figure 2.13) the

density of drilling has returned adequate data to produce a

greatly improved geological understanding and an

updated mineral resource estimate. Indicated resources

total 16.1 Mt averaging 16.4 g/t Au and 14.2 g/t Ag;

inferred resources total 5.4 Mt averaging 17.0 g/t Au and

15.7 g/t Ag. Both resource estimates are based on 5.0 g/t

gold-equivalent cut-off grades. Best intercept to date on

the property was drilled this year in SU-452: 0.5 m

grading 41 582 g/t Au plus 27 725 g/t Ag from 201.47 m

(Figure 2.3); part of a broader 10.71 m grading 2 393 g/t

Au plus 1 605 g/t Ag from 198.79 m. To date, 66

intervals from VOK have returned grades over 1 000 g/t

Au; 41 of which were drilled in 2012. The VOK zone is

showing continuity to the Galena Hill zone and has been

extended over 800 m along strike and remains open in all

directions including to the west, across the Brucejack

Fault. Additional West Zone measured plus indicated

resources updated in April total 4.9 Mt averaging 5.85 g/t

Au plus 267 g/t Ag. Additional inferred resources total

4.0 Mt grading 6.44 g/t Au plus 82 g/t Ag.

Due to the high-grade nature of the VOK deposit,

strict modelling methods were used to mitigate oversmoothing

of grades or “the nugget effect” in the resource

estimate. The method included separating gold grades

into two representative populations: 1) pervasive,

background low grade up to 5 g/t Au and 2) discrete highgrade

up to 421 g/t Au. Ordinary kriging on 10 m x 10 m

x 10 m blocks was used to model the low grade

populations while multiple indicator kriging was to

estimate high-grade populations and control the skewness

of the data. The multiple indicator kriging does not

exclude the extreme grades but does limit the influence of

the high-grade sample in the block model. High and

extreme grades are incorporated into a mathematical

model then used to populate discrete sized blocks of highgrade

mineralization which are incorporated into parent

blocks twice the size of the low grade blocks, therefore

limiting the influence of high grades while still

acknowledging them. Further to the conservative

estimation, areas of dense drilling data that approach the

measured resource requirements outlined by the Canadian

Institute of Mining have been retained in the indicated

category until detailed underground sampling is done.

Underground re-development of the historic West

Zone decline is well underway with slashing activities

expanding the decline to 5 m x 5 m dimensions to the

1330 m level. From the 1314 m level, a new 450 m

decline will be excavated to the 1270 m level in the VOK

zone where a 10 000 tonne bulk sample will be mined in

mid 2013 to validate continuity of high-grade

mineralization. A feasibility study is expected to be

completed by Q2 2013 and plans for a 2700 tonne per day

underground mine. Planned mining method will be a

combination of longitudinal and transverse long-hole

stope mining followed by cemented paste backfill. Road

access from highway 37 to the site is scheduled to be

completed by the end of 2012.

Brucejack sits on the eastern limb of the broad

northerly trending McTagg anticlinorium; a regional

scale, mid-Cretaceous structural culmination in the

Western Skeena Fold Belt. Brucejack property

stratigraphy comprises of Triassic Stuhini Group

sediments and volcanics unconformably overlain by

Jurassic Hazleton Group volcanics followed by Bowser

Lake Group sediments. Property lithologies generally dip

moderately and young to the east and are variably altered.

Lithologies are cut on the west side of the property by a

topographic lineament, the Brucejack Fault (Figure 2.14)

of uncertain displacement and interpreted history of

long-lived re-activation. Alteration is dominated by

pervasive strong to intense quartz-serecite-pyrite

replacement up to several hundred meters or more wide

and approximately 5 km strike length. Most of the five

defined mineral resources (West Zone, Valley of the

Kings, Bridge Zone, Gossan Hill and Shore Zone) are

within the intensely altered zone and associated with veinstockwork

systems of varying intensity. Stockworks

display good continuity and in rare cases range up to 10 m

wide. High-grade zones are either on the margins or

contained within 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, euhedral pyrite is barren.

Mineralization at the Brucejack property is

hypothesized to represent a deformed transitional meso –

epithermal porphyry-associated stockwork in pervasively

altered lower Hazleton Group rocks; possibly associated

with the high levels of the KSM porphyry system.