In August 2002, M. Mihalynuk of the British Columbia Geological Survey discovered massive sulphide mineralization during regional mapping in the Atlin area. The Joss'alun occurrence was discovered as part of a mapping program conducted under the joint federal and provincial Atlin Targeted Geoscience Initiative. The Joss'alun discovery is located approximately 75 kilometres by air, southeast of the community of Atlin. Access is by helicopter and the closest road access is a very rough fire abatement road that ends at Kuthai Lake, 30 kilometres northwest of the occurrence.
The area is underlain by submarine basalt flows, flow breccia, tuffaceous rocks and comagmatic mafic intrusive rocks of the oceanic Cache Creek Complex (upper Mississippian to Permian Nakina Formation). Textures displayed by the unit along strike of the Joss'alun occurrence confirm a submarine setting as pillow basalt, radiolarian-bearing Fe(iron)-rich chert and laminated interpillow micrite are well displayed. The mafic unit is structurally underlain by very dense and magnetic ultramafic rocks of the Nahlin body, interpreted as part of the ancestral Earth's mantle. Unconformably overlying the basalt is a unit comprised of very immature sedimentary rocks, mainly conglomerates, derived from both local and exotic sources.
Mineralization consists of a series of stacked, apparently conformable lenses of semimassive chalcopyrite and lesser pyrite, which are hosted by a dominantly mafic volcaniclastic unit. Individual lenses exceed 3 metres in strike length and are up to 90 centimetres thick. The mineralized discovery zone is approximately 190 metres in an east-west direction and 120 metres in a north-south direction. Some thin chalcopyrite veins (up to 5 centimetres thick) are clearly discordant. Sulphides in the lenses appear brecciated. Sparse blebs of chalcopyrite have been observed in outcrop up to 1 kilometre away, along the trend of the hostrocks in the discovery zone.
Samples assayed up to 9.77 per cent copper in grab, 3.35 per cent copper over a 90-centimetre chip, and 6.65 per cent copper over a 35-centimetre chip (personal communication - M. Mihalynuk, September 2002).
In 2008, a drillhole (BN08-10) was targeted on coincident induced polarization (IP) chargeability and copper soil geochemical anomalies located 250 metres northwest of the previously drilled Joss'alun showing. Copper mineralization occurs either as trace to 2 per cent disseminated chalcopyrite in tuffs and breccias or associated with epidote alteration in pillow margins. The best result from this hole was 3.12 metres grading 0.665 per cent copper from 220.62 metres including 1.00 metre grading 1.23 per cent copper from 221.62 metres (Assessment Report 30752).
Copper Ridge Explorations Inc. staked the Joss’alun ground in late 2002. In 2003, Imperial Metals Corporation optioned the claims to consolidate ownership into the Nak project and undertook a comprehensive exploration program. Chalcopyrite occurs as massive pods and discontinuous veins that are interstitial to poorly developed pillows and lesser agglomerate in basalt of the Cache Creek Complex. Pyrite and epidote are associated with chalcopyrite. Bodies of gabbro invade the mafic volcanic rocks and, based on their chemical similarity, are closely related. In the Joss’alun zone, geological mapping and soil geochemistry led to selection of drill targets. All seven holes drilled in the Joss’alun zone yielded significant copper values. The best intercepts are 0.94 per cent copper over 17.8 metres in hole 5, and 0.34 per cent copper over 53.4 metres in hole 7 (Exploration and Mining in British Columbia 2003, page 6). Two holes in the Jennusty zone failed to intersect significant copper mineralization. The Jennusty (104N 137) is a new occurrence about 1.7 kilometres north-northwest of Joss’alun.
Imperial Metals Corp. announced in early 2004 that it would not be proceeding with its option on the Joss'alun copper property. Consolidated Norsemont Ventures Ltd signed an agreement on June 2004 with Copper Ridge Explorations whereby Norsemont will have the right to earn up to a 75% interest in the property. Consolidated Norsemont completed an IP survey on the property in 2004. In 2007, Copper Ridge Explorations Inc. conducted mapping, prospecting and geochemical sampling; 97 soil samples and 12 grab samples were collected. In 2008, Lomiko Resources Inc. completed an exploration program consisting of an airborne geophysical survey and a follow-up program of ground geophysics (IP over 4.4 kilometres), line cutting, soil sampling (275 samples), mapping, prospecting and diamond drilling (three holes totalling 759.8 metres). Two holes (516.3 metres total) of the drill program were completed on the Box Lake showing (104N 139) located 2.6 kilometres southeast of the Joss'Alun. The airborne geophysics comprised an AeroTEM electromagnetic and magnetic survey over 603 line kilometres.
In 2015, Imperial Metals Corporation carried out prospecting, rock and soil sampling programs on the Nak property in an area between the Joss'alun and Box Lake occurrences. A total of 30 soil samples and 4 rock samples were taken.
