The GK occurrence is situated in the Swannell Ranges (Omineca Mountains), approximately 20 kilometres north of Old Hogem and 61 kilometres northeast of Takla Landing.
The area is underlain by mesozonal plutonic rocks assigned to the Late Triassic to Early Cretaceous Hogem Intrusive Complex that have been emplaced into volcanic rocks of the Middle Triassic-Lower Jurassic Takla Group, east of the Pinchi fault zone. The plutonic rocks form an elongate batholith, extending from Chuchi Lake north to the Mesilinka River. The structural setting of the batholith and the intruded Takla Group is one of vertical tectonics associated with graben development (Bulletin 70).
Mapping carried out in the area in the early 1970s identified two major rock units: 1) granitoid rocks of the Hogem Intrusive Complex and 2) Duckling Creek Syenite Complex, a Middle Jurassic phase of the first unit. The most common granitoid rocks are quartz-bearing monzodiorite and monzonite, whereas the Duckling Creek rocks include porphyritic to pegmatitic syenite and holomafic pyroxenite. All of these rocks have reportedly been potassium feldspathized by fluids that preceded and accompanied the emplacement of the syenite complex (Assessment Report 3610, page 35).
A copper showing associated with dike emplacement has been located on the ridge immediately north of the Lorraine occurrence (MINFILE 093N 002). The mineralization occurs over a width of 61 metres but can be traced for only 53 metres across the ridge before becoming obscured by talus. Malachite and chalcopyrite are hosted, not only by the underlying intrusive rocks, but also within small quartz veins. The grade of this mineralization has been visually estimated at 0.3 per cent copper (Assessment Report 3995, page 8).
Small, glassy quartz veins are common throughout the map area, cutting all rock types. One unusually large vein, traced for over 41 metres along strike and averaging 60 centimetres wide, is exposed approximately 700 metres south-southwest of the ridge showing (Assessment Report 3995, Plate 1). This vein reportedly hosts malachite as well as a lens of massive chalcopyrite.
Other showings in the area include ultrabasic dikes hosting significant chalcopyrite and malachite mineralization over an area 36 by 15 metres further south on the same ridge, and fractures hosting up to 2.5 centimetres of bornite mineralization east of the Lorraine occurrence.
Work History
In 1971, geological mapping and soil geochemistry program was completed by Luc Syndicate on the COL claims.
In 1972, a geological mapping program was conducted by Luc Syndicate on the central and southern portions of the COL claims.
In 1990, a 2630 line-kilometre airborne magnetometer and very low frequency electromagnetic geophysical survey on the Duckling Creek properties was conducted by Golden Rule Resources Ltd.
In 2019, Teck Resources Limited conducted an airborne magnetic survey aimed at enhancing resolution of historical magnetic datasets and developing geological and structural understanding in the northeast portion of the Lorraine-Jajay and Jan-Tam-Misty mineral tenure. The survey identified potential new features in the Steelehead and Fox prospective areas.
