The Swannell occurrence is located on the Swannell River, 6.6 kilometres south of the historic Ingenika mine (094C 002) near Delkluz Lake, approximately 100 kilometres north-northeast of the community of Germansen Landing and 195 kilometres northwest of Mackenzie.
The area is underlain by carbonate strata belonging to the Cambrian to Ordovician Kechika Group, which unconformably overlie sandstones of the Neoproterozoic Ingenika Group. The Kechika Group forms the core of a broad north-plunging syncline that outcrops approximately 3 kilometres south of the Swannell River.
The showings are located on both banks of the Swannell River, with the best exposures in a deep trench cut by the river. The showings are subparallel to each other and consist of stratabound lead-zinc-silver. The main Swannell showing is the most significant of the group in terms of size and grade. Host rocks are dark grey to black argillaceous schists and slates interbedded with thinly bedded, blue-grey limestones (Geological Survey of Canada Memoir 274), all of which are probably part of the Ingenika Group. The rocks are highly sheared and contorted, generally with a northwest strike and a vertical dip. Graphite is common in the rocks as are white quartz veins up to 2.5 metres in width, which are commonly parallel to bedding.
Mineralization is controlled by carbonate lithology and structure. Base metal mineralization at the Swannell showing has a strike of 325 degrees and dips steeply to the east with a measured plunge of 60 degrees north. Galena, sphalerite, and pyrite are deposited as veins and disseminated replacements in dolomitized limestone and limy siltstone. Two parallel base metal mineralized horizons consisting of silicified dolomite with tan, brown and black sphalerite, galena, and pyrite are separated by 30 metres of carbonaceous siltstone and limestone. Drilling results indicate potential structural folding and deformation at depth. According to the Geological Survey of Canada Memoir 274, three types of mineral deposits are present on the Swannell property.
The first deposit type consists of quartz veins carrying up to 5 per cent pyrite and galena, sphalerite, minor malachite and covellite. One 0.5-metre-wide vein exposed over a length of 50 metres had been repeated by isoclinal folding to a width of 2.5 metres.
The second mineral deposit type consists of layers of quartz, crystalline calcite, sphalerite, galena and minor pyrite in blue-grey, thinly bedded limestone. The host strata are drag folded, and the mineralized layers are stratiform. A composite assay (Geological Survey of Canada Memoir 274, page 210) of two selected samples yielded 0.69 gram per tonne gold, 279.1 grams per tonne silver, 0.05 per cent copper, 24.6 per cent lead and 27.4 per cent zinc.
The third type of mineral deposit consists of bedding-parallel layers of coarse granular pyrite and fine galena and sphalerite in brecciated, silicified blue-grey limestone. One layer containing approximately 10 per cent sulphides reaches 3 metres in thickness. Some layers consist of semi massive sulphides. In a 1985 diamond drill program (Assessment Report 14032), Cominco Limited reported "fracture-controlled" galena-sphalerite mineralization and a grade of 0.23 per cent lead and 5.2 per cent zinc across 9.5 metres in the best hole.
The first claims in the area, the Dominion claims, were staked by H. Ravenal in 1936. Hand trenching was completed and the claims were examined by E. Brunland on behalf of Consolidated Mining and Smelting Company of Canada Limited (Cominco). In 1956, G. Ola staked the claims as the Swannell, Dell, Mike, Pedro and Fox claims. Cominco optioned the claims and completed geological mapping and sampling. In 1957, Cominco conducted regional and local mapping, geophysical surveying, and drilling on the Swannell property. Seven AQ-size drillholes totalling 336 metres were completed and three drillholes were abandoned in overburden. Cominco then terminated the option on the property.
Northlode Exploration Limited restaked the claims in 1966 and completed airborne and ground geophysical surveying, soil geochemistry, prospecting, trenching, geological mapping, and drilling. In 1967, a gravity geophysical survey was completed on a grid to the southwest of Delkluz Lake. Three drillholes were completed on gravity anomaly targets on the south side of the Swannell River but results of the drilling were never made available.
In 1981, Cominco Limited restaked the Swannell claims as the Kluz 1 to 4 claims. The following year, A.B. Mawer examined and re-evaluated the property on behalf of Cominco. In 1984, Cominco, through a joint venture with Elite Resources, completed horizontal-loop electromagnetic and induced polarization geophysical surveys. The following year, the Kluz 5 claim was staked and the joint venture completed three NQ-size diamond-drill holes totalling 465.7 metres on the southeastern corner of the Kluz 1 claim. Further drilling on the base metal horizon was recommended but not completed. In 1998, Cominco returned to the property, performed a site clean-up and restacked all of the 1985 drill core.
In 2001, Cross Lake Minerals Limited optioned the Swannell property from Teck Cominco (formerly known as Cominco) and staked the Del 4 and 5 claims. That year, Cross Lake undertook an exploration program consisting of geochemical sampling and drilling on the Swannell and Ingenika (094C 002, 3, 86) properties. A mobile metal ion (MMI) geochemical sampling technique was first tested on the Onwards South showing (094C 182) to the north. After receiving favourable results from the trial run, a MMI soil sampling grid was used to trace the strike extension of the known Swannell showing and explore for new mineralization. Three BQTK-size diamond-drill holes totalling 400.8 metres were completed on the Swannell property. The three holes were drilled to the west across the mineralized horizons on the north side of the Swannell River in the vicinity of the 1957 and 1985 Cominco drillholes and trenches. Two of the drillholes, holes CS-01-08 and CS-01-10, intersected both of the mineralized horizons. In 2002, Cross Lake completed four diamond-drill holes: one on the Ingenika property and three on the Swannell property. The drillholes were designed to test the MMI anomalies identified in 2001. Ownership of the Swannell property was transferred to Selkirk Metals Holdings Corporation in 2005. Selkirk later forfeited the claims in 2007.
Results from the 1957 drill program included 1.7 metres grading 14.5 per cent zinc, 4.3 per cent lead and 37.7 grams per tonne silver and 1.8 metres grading 15.4 per cent zinc, 1.2 per cent lead and 10.3 grams per tonne silver from drillhole CS-57-01 (Assessment Report 26702). From the 1985 drill program, drillhole CS-85-06 intersected 9.6 metres grading 5.83 per cent zinc, 1.29 per cent lead and 15.3 grams per tonne silver, including 2.8 metres grading 12.04 per cent zinc, 0.99 per cent lead and 11.3 grams per tonne silver (Assessment Report 26702). In 2002, drillhole CS-02-14 intersected a graphitic fault zone containing low-grade sphalerite, galena, and pyrite with crushed limestone fragments. The interval occurred from 64.4 to 65.4 metres and graded 2.97 per cent zinc and 0.68 per cent lead (Assessment Report 27253).
In 2015, Spearhead Mining Corporation completed a program of reconnaissance geological mapping, prospecting, and rock sampling (29) on the Swannell property which covered the Onward South (094C 182), Onward (094C 003) and Swannell occurrences. Rock samples confirm the high-grade nature of massive sulphide areas that have been sampled in earlier exploration campaigns.
In 2018, on behalf of Spearhead Mining Corporation, a program consisting of detailed rock sampling in addition to a pilot biogeochemical tree bark survey was carried out over claims covering the Onward, Swannell and Onward South showings. A total of 18 rock samples and 175 tree bark samples were taken.
