British Columbia Ministry of Energy, Mines and Natural Gas and Responsible for Housing
News | The Premier Online | Ministries & Organizations | Job Opportunities | Main Index

MINFILE Home page  ARIS Home page  MINFILE Search page  Property File Search
Help Help
File Created: 14-Nov-2012 by Garry J. Payie (GJP)
Last Edit:  24-Mar-2022 by Nicole Barlow (NB)

Summary Help Help

NMI
Name BRIDGE, BRUCEJACK, SULPHURETS Mining Division Liard
BCGS Map 104B050
Status Prospect NTS Map 104B08E
Latitude 056º 27' 10'' UTM 09 (NAD 83)
Longitude 130º 11' 15'' Northing 6257100
Easting 426800
Commodities Gold, Silver, Zinc, Lead, Molybdenum Deposit Types L02 : Porphyry-related Au
L03 : Alkalic porphyry Cu-Au
H05 : Epithermal Au-Ag: low sulphidation
H08 : Alkalic intrusion-associated Au
Tectonic Belt Intermontane Terrane Stikine
Capsule Geology

The Bridge zone is centered on a 3-hectare nunatak outcrop surrounded by ice of the eastern arm of the Sulphurets glacier. The area is characterized by strong sericite-pyrite alteration and is transected by a number of discontinuous mineralized quartz veins.

Based on the encouraging gold assays obtained from historical rock-chip sampling plus values obtained from the 2009 channel saw-cut rock geochemical program, Silver Standard tested the Bridge zone in 2009 with drill hole SU-10. Assay results for this drill hole showed that it intersected a broad zone of low-grade gold mineralization of possible economic significance. The mineralized intercept in SU-10, extending from surface, was reported as being 483 metres long, averaging 0.70 gram gold per tonne (as reported in Assessment Report 32074). This hole was re-entered and extended for an extra 118 metres and still ended in mineralization. The last 118 metre averaged 0.99 gram per tonne gold (as reported in Assessment Report 32074). The discovery of potentially bulk mineable gold at the Bridge zone prompted Silver Standard to drill twelve diamond boreholes in 2009 and an additional 21 holes in 2010 to probe for the limits of this mineralization. These drill holes determined that the bulk of the gold mineralization is hosted by an andesitic hornblende-plagioclase porphyry of the upper Unuk River Formation (Hazelton Group) that in general is moderately sericite-chlorite altered, with disseminated and stringer pyrite making up a few percent of the rock by volume. The iron sulphide is commonly seen replacing hornblende phenocrysts. Quartz plus/minus chlorite plus/minus sericite veins, 20 to 200 centimeters in thickness, were intermittently intersected by the drill holes, and these commonly contain minor to trace amounts of pyrite, sphalerite, galena, molybdenite and unknown dark grey, silver-bearing sulfosalt(s). Gold appears to be associated with the pyrite which also tends to contain arsenic in its mineral structure where gold is present. Core samples that yielded gold contents greater than 3 grams per tonne gold typically contain quartz veins with trace to minor amounts of electrum and native gold.

In 2010, drilling highlights included hole SU-87 which intersected 168 metres grading 1.09 grams per tonne gold and 4.04 grams per tonne silver and ended in mineralization (Armstrong, T.A. (2011-04-04): Technical Report and Updated Resource Estimate on the Snowfield-Brucejack Property).

Drilling in 2011 targeted a few of the high-grade intersections and the suggestion is that they are structurally controlled. Intersections include 458 grams per tonne gold in a one-meter intersection in hole SU-125, and a 19.0 grams per tonne gold intersection across 5.85 metres in hole SU-166 (Technical Report and Resource Estimate on the Brucejack Project for Pretium Resources, January 12, 2012).

In 2015, it was reported that results from holes SU-671 and SU-673, in conjunction with exploration work completed to date, demonstrated that the Valley of the Kings (104B 199), West Zone (104B 193), Flow Dome Zone, Bridge Zone, and Kitchen View Zone were part of a large hydrothermal system that has a larger area extent than previously thought.

Refer to West (104B 193) for complete geological details and related bibliographic information on those zones explored by Pretium Resources as part of the Brucejack Property.

Bibliography
EMPR BULL 63
EMPR EXPL 1976-E181; 1977-E222; 1980-464; 1981-248; 1982-382; 1983-520; 1986-B57, C441; 2011-16,18; 2012-33; 2013-47; *2014-101; 2015-128
EMPPR EXPLORATION OVERVIEW 2016-154,155,160
EMPR FIELDWORK 1982, pp. 171-174; 1987, pp. 199-209
EMPR MAP 65 (1989)
EMPR OF 1988-4
EMPR PF (Bridge, D.A., Ferguson, L.J. and Brown, M.G. (1981): 1980 Exploration Report on the Sulphurets Property for Esso Minerals Canada Ltd. (unpublished); Bridge, D. and Melnyk, W. (1982): 1981 Exploration Report on the Sulphurets Property for Esso Minerals Canada Ltd. (unpublished); Bridge, D. and Melnyk, W. (1983): 1982 Exploration Report on the Sulphurets Property for Esso Minerals Canada Ltd. (unpublished); Britten, R.M. (1983): Regional Geological Assessment of the Stewart-Sulphurets Area, and Geology and Alteration of the Sulphurets Prospect Area for Esso Minerals Canada Ltd. (unpublished); Lomenda, M.G. (1983): Geology, Alteration and Mineralization of the Mitchell-Sulphurets Ridge and Snowfields Gold zone, Sulphurets Property for Esso Minerals Canada Ltd. (unpublished); Melnyk, W. (1983): 1983 Canada Ltd. (unpublished); Geology Map - 1:31,250 Scale - Newmont Exploration of Canada Ltd., 1960's; Newhawk Gold Mines Ltd.,: Annual Reports for 1985, 1986 and 1987; News Releases for Dec.10, 1985, Jun.3, Jul.1,16,20, Aug.24, Oct.5, Nov.5,13,30, 1987, Feb.12, Apr.13, May 17, 1988; Third Quarter Report, 1987)
GSC MAP 9-1957; 1418A
GSC P 89-1E, pp. 145-154
PR REL Pretium Resources; Oct.13,22, 2009; Jul.12,29, Sep.8,13, Oct.6,20, 2010; Jul.7,27, Nov.27 2011; Dec.15, 2015
Kirkham, R.V. (1963): The Geology and Mineral Deposits in the Vicinity of the Mitchell and Sulphurets Glaciers, M.Sc. Thesis, U.B.C.
Simpson, T.M. (1983): The Geology and Hydrothermal Alteration of the Sulphurets Deposits, Northwest British Columbia, M.Sc. Thesis, University of Idaho
Armstrong, T.A. (2010-01-14): Technical Report and Resource Estimates on the West, Bridge, Galena Hill, Shore, SG & Gossan Hill Gold & Silver Zones of the Brucejack Property
Ghaffari, H. (2010-09-10): Technical Report and Preliminary Assessment of the Snowfield-Brucejack Project
Ghaffari, H. (2010-10-28): Technical Report and Preliminary Assessment of the Snowfield-Brucejack Project
Armstrong, T.A. (2011-03-04): Technical Report and Updated Resource Estimate on the Brucejack Property
*Armstrong, T.A. (2011-04-04): Technical Report and Updated Resource Estimate on the Snowfield-Brucejack Property
Ghaffari, H. (2011-06-03): Technical Report and Preliminary Economic Assessment of the Brucejack Project
Armstrong, T.A. (2012-01-12): Technical Report and Resource Estimate on the Brucejack Property
Ghaffari, H. (2012-02-20): Technical Report and Updated Preliminary Economic Assessment of the Brucejack Project
*Feasibility Study and Technical Report Update on the Brucejack Project, dated June 19, 2014.
Jones, I. (2019-04-04): Technical Report on the Brucejack Gold Mine
Pretium Resources Inc. (2020-03-09): Technical Report on the Brucejack Gold Mine, Northwest British Columbia
WWW www.pretivm.com

COPYRIGHT | DISCLAIMER | PRIVACY | ACCESSIBILITY