The Brett occurrence is located on the western slopes of Mount Reed, north of McDame Creek and approximately 3.5 kilometres east-southeast of the south end of Hot Lake.
Regionally, the area is underlain by quartzite and quartz arenite sedimentary rocks of the Boya Formation and limestone, marble and calcareous sedimentary rocks of the Rosella Formation, both of the Lower Cambrian Atan Group, and limestone, slate, siltstone and argillite of the Cambrian to Ordovician Kechika Group. The sedimentary units have been intruded by granites of the Eocene Mount Reed stock.
Locally, a magnetite-sphalerite skarn zone has been identified. Drilling has delineated a strike length of approximately 60 metres with a downdip extension of approximately 55 to 60 metres. The Brett zone skarn appears to be striking at an azimuth of 100 degrees to 110 degrees and dipping steeply to the south. There appears to be two magnetite-sphalerite–rich sections to the Brett zone. Molybdenum mineralization is also reported to occur in both skarn and hornfels lithologies; however, the higher grades of molybdenum are seen in the skarn units. The Brett zone remains untested along strike to the southeast and northwest and is open along its downdip extensions.
In 1997, diamond drilling yielded intercepts including 7.03 per cent zinc over 4.7 metres, 13.26 per cent zinc over 7.0 metres and 4.92 per cent zinc over 5.2 metres in hole DGBZ 97-1, and 5.08 per cent zinc over 0.9 metres and 10.7 per cent zinc over 10.3 metres in hole DGBZ 97-2 (Assessment Report 25254). Based on 1980 and 1997 drillholes, a drill-inferred reserve of 436,000 tonnes grading 10 per cent zinc was reported. This is not NI 43-101 compliant and should not be relied upon but may referred to as a historical estimate (Carpenter and Gilmour, 2008, page 35). Subsequent drilling, in 1997, on the extensions of the mineralized zones yielded up to 8.15 per cent zinc over 2.6 metres in hole DGBZ 97-9, located northeast of the previous drillholes (Assessment Report 25254).
In 2014, five of six drillholes intersected the Brett zone magnetite-sphalerite skarn. Drillholes 14-02 through 14-05 intersected the Brett zone and magnetite sphalerite skarn is at bedrock surface in drillholes 14-03, 14-05 and 14-06, with grades of 0.92 per cent, 1.78 per cent and 1.09 per cent zinc, respectively, within the top 5 metres (Assessment Report 35008). One 9.7-metre interval (not true widths) in DDH 14-02 assayed 7.27 per cent zinc (Pacific Bay Minerals Ltd., News Release, December 9, 2014).
Exploration work has also outlined three areas of strongly anomalous lead, zinc and silver mineralization. The areas include the Dan zone, located off the northwestern corner of the Brett grid, on a small hill approximately 400 metres northwest of the Brett occurrence, and two large areas within the Hot Lake grid. The Dan zone comprises a fault zone in limestone hosting galena-sphalerite veinlets, up to 0.1 metre wide. The two areas of anomalous soil geochemistry within the Brett grid documented up to 9082 parts per million lead and up to 34.9 parts per million silver; background lead values average 122 parts per million (George Cross News Letter No.223 [November 10], 1997).
In 1997, a 2-metre chip sample (149828) from the Dan zone assayed 1.45 per cent lead, 5.23 per cent zinc and 21.7 grams per tonne silver, and a nearby grab sample (149824) of limestone assayed 0.30 per cent tungsten (Assessment Report 25254).
Work History
In 1969, an aeromagnetic survey was flown for Brettland Mines Ltd. over an area that covered much of the same ground as does the present property. The survey revealed magnetic features that were interpreted as indicating major faulting and possible skarn type mineralization.
In 1970, geological mapping, a magnetometer survey, trenching and a 14-hole, 1250-metre drilling program was completed. All the options were dropped by 1971. In 1971, Reed Mines Ltd optioned the property from J. Reed. The property was optioned from Reed Mines by Glen Copper and four holes, totalling 375 metres, were drilled. During 1978 through 1981, Canadian Superior Exploration Ltd. completed program of geological mapping, geochemical (rock and silt) sampling and diamond drilling on the area as the Mount Reed property. This work was centred on molybdenum-tungsten skarn mineralization associated with the nearby Mount Reed (MINFILE 104P 043) occurrence.
In 1996, Daniel W. Brett completed a program of geological mapping and rock sampling on the area as the Reed property. In 1997, Demand Gold carried out a program of reconnaissance prospecting, geological mapping, a magnetometer survey and a soil geochemical survey. Nine drillholes on the Brett zone, totalling 1019 metres, were drilled to test magnetic highs thought to be related to zinc-lead-silver–bearing skarns (Assessment Report 25254). Zinc zones were encountered in three of the holes.
In 2008, Pacific Bay Minerals Ltd. completed a 917.0 line-kilometre airborne magnetic and electromagnetic survey on the area as the Haskin-Reed property. The following year, a program of geochemical (rock, silt and soil) sampling and trenching was completed on the property.
In 2014, Pacific Bay Minerals Ltd. completed six diamond drill holes, totalling 408.6 metres, on the Brett occurrence.
