The Gertie occurrence is located at an elevation of approximately 1480 metres on a northwest-facing slope, east of the Klawli River and approximately 3.5 kilometres south-southeast of the south end of Klawli Lake.
Regionally, the area is underlain by volcanic flows of the Lower Jurassic Chuchi Lake Formation and volcaniclastic rocks of the Upper Triassic Witch Lake Formation, both of the Takla Group, which have been intruded by ultramafic rocks of the Upper Triassic to Lower Jurassic Valleau Creek Plutonic Suite and granitic rocks of the Lower Cretaceous Klawli Pluton to the north, and quartz monzonitic to monzogranitic rocks of the Lower Jurassic Hogem Plutonic Suite to the south.
The westernmost outcrop is exposed along a glacial gully. An amygdaloidal, maroon and grey, plagioclase phyric latite flow hosts disseminated and fracture controlled malachite and minor azurite. Pink calcite (rhodochrosite?) and jasperoid quartz occur as vesicle infillings. A single grab sample from this locality yielded 0.2 per cent copper (Fieldwork 1991, page 116). A brecciated zone in a more greenish and aphanitic area of the outcrop contains minor chalcopyrite and has areas of bleaching and hairline fractures with chlorite envelopes. Multidirectional vuggy quartz veinlets are also present, and some contain malachite.
Native copper blebs, 1 by 2 centimetres in size, are associated with carbonate and jasper in open-space fillings and occur within a highly amygdaloidal part of the same flow package, 75 metres north of the gully. Two, 1-metre wide zones of strong propylitic alteration (epidote, chlorite) cut the outcrop and contain disseminated malachite.
An altered and bleached intrusive body outcrops 150 metres south of the gully. It contains a crackle breccia that grades into a matrix-supported breccia with milled fragments of intrusive rock floating in a hematite-rich matrix; no sulphides were visible at this locality.
The eastern outcrop is 1.2 kilometres northeast of the native copper showing. Brecciated green, grey and maroon crystal-lapilli tuff contains disseminated malachite, chalcocite and possibly tetrahedrite. A representative grab sample from this outcrop yielded 1.08 per cent copper and 17.5 grams per tonne silver (Fieldwork 1991, page 116).
Work History
During the early 1970s, Dolmage Campbell, on behalf of Umex, conducted initial exploration in the Jan claim area. This work outlined copper stream sediment anomalies in creeks draining the southwestern side of Klawli Lake. Campbell then performed a program consisting of line cutting, soil sampling, and a ground magnetometer survey on claims covering the stream sediment anomalies. The magnetometer survey duplicated the aeromagnetic anomaly on Klawli Lake, and the soil sampling outlined some copper anomalies just south of central Klawli Lake. Interpretation of the soil results was hampered by a thick layer of glaciofluvial material, as well as peat bogs. Placer further reports that several years later, Bernard Kahlert documented anomalous copper and gold values (over 600 parts per million copper, and up to 110 parts per billion gold) collected along the southern edge of the Andy claims, where the aeromagnetic anomaly drops off, confirming the Umex anomalies.
In 1989, Cathedral Gold Corp. completed a program of geological mapping and geochemical (rock and soil) sampling on the area north east of the Gertie occurrence as the Awl 1-3 claims.
The Jan claims were staked in 1990 by S. Visser. The claims were staked to cover a magnetic high. In 1991, Pacific Rim Mining Corp, on behalf of Visser, prospected the Jan claims and collected rock and silt samples. The Gertie showings were discovered by members of the BC Geological survey mapping crew on the Jan 12 claim in 1991. In 1992, Placer Dome was the operator. They collected 3 rock, 1 silt and 315 soil samples. The also conducted 12 kilometres of ground magnetic and electromagnetic surveying and 8.8 kilometres of induced polarization surveying. An induced polarization anomaly, roughly 400 metres wide and open to the north and east, into Klawli Lake was found and may represent a mineralized contact between pyroxenite and Takla volcanics. No Gertie style mineralization was found in outcrop or float during the 1992 program. However, outcroppings on the main grid were sparse.
In 2007, Solomon Resources Ltd. completed a program of geochemical (soil and silt) sampling and a 1458.4 line-kilometre airborne geophysical survey on the area as the Col-Magnet property.
In 2013 and 2014, Pacific Empire Minerals Corp., in conjunction with Nation River Resources Ltd. and Indata Resources Ltd., completed programs of geochemical (rock and soil) sampling and historical data compilation on the area as part of the Col-Later-Klawback property.
