how far the brucejack fault runs through the high property is unknown but the high is full of gossanous zones akin to the 10 kilometer long corridor between the brucejack and the snowfield deposit :::;;
One significant item this map illustrates is that along the trend of the Brucejack Fault, from the south end of the Brucejack Property north to the Snowfield Property and beyond, one never appears to be very far stratigraphically above or below the Stuhini Group-Hazelton Group unconformity. Therefore, like the Brucejack Fault itself, the unconformity is co- spatial with the regional-scale gossanous Sulphurets alteration system, and with most of the camp?s more significant mineral resources.
The Brucejack Fault is a very obvious topographic lineament. In spite of this, there is considerable discussion about the timing of potential movement on the fault. A much thicker section of Hazelton Group rocks on the east side of the fault suggests considerable east-side-down displacement, which may be interpreted as reflecting post-depositional displacement. Alternately, the presence of the overlying uppermost Salmon River Formation fine clastic units suggests that much of the movement was probably syn- volcanic, and that any later movement on what is the present trace (the lineament itself) was not large.
At Brucejack, the alteration and most of the mineralization and alteration are concentrated in the north – south arcuate band of gossanous rock, which is part of the Sulphurets alteration system. The rocks which host much of the alteration are part of lowermost Hazelton Group, which suggests that the unconformity with the underlying rocks of the Stuhini Group may have helped focus or control the emplacement of alteration and mineralization. It is also possible that some of the more porous and permeable rocks close to the unconformity, such as the conglomerates overlying it, may have helped focus or channel the alteration, and to some degree the mineralization. All of this has clearly been modified by later deformation and/or structures.
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3 April 2012 36 of 111
Pretium Resources Inc.: Brucejack Project
Mineral Resources Update Technical Report
The unconformity and the rocks which overlie it are relatively close to the surface the entire distance between the Brucejack and the Snowfield deposits, which is a distance of nearly 10 km. To the east, these rocks are commonly overlain by other, less readily altered lithologies, suggesting that very good potential exists for locating blind deposits in that direction, as well in places along the Brucejack-Snowfield trend where less altered rocks may overlie more favourable stratigraphy.
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