The Black Rock North occurrence is located north the junction of Sheep Creek and Annie Rooney Creek at an elevation of approximately 1050 metres.
Regionally, the area is underlain by fine clastic sediments of the Lower to Middle Ordovician Active Formation, undivided sedimentary rocks of the Cambrian Laib Formation, quartz arenite sedimentary rocks of the Neoproterozoic to Lower Cambrian Hamill Group and sedimentary rocks (limestone, slate, siltstone and argillite) of the Triassic to Jurassic Ymir Group, which have been intruded by granodioritic rocks of the Cretaceous Anstey pluton and small stocks of syenitic to monzonitic intrusive rocks of the Eocene Coryell Plutonic Suite.
The area lies within dolomitized limestone of the westernmost unit of the Lower Cambrian Laib Formation, Reeves member (correlative with the Badshot Formation). The Reeves limestone is interbedded with quartzites and phyllites with near-vertical dips. Minor amounts of skarn minerals have developed within the limestone and hornfelsed sediments.
Locally, north-trending shears have been welded by irregular lenses of white quartz, which are up to 1 metre in width but are barren of sulphides. Scattered lenses of disseminated sphalerite are hosted by dolomite and limestone and the largest of these lenses is approximately 5 metres in width and has a north-south strike length of approximately 9 metres.
On the north side of Sheep Creek, on the Black Rock 11 (Lot 14405) claim, two types of sulphide-bearing float boulders have been identified. The higher elevation boulders contain sphalerite and galena cementing silicified limestone breccia, whereas float identified at lower elevations containing alternating layers of galena, sphalerite and wollastonite, interpreted as skarn mineralization, was found in place on the HB Mine property immediately east of the Black Rock 10 (Lot 14408) claim.
In 1986, samples (BR86-08 and -09) from the lower zone of float boulders yielded up to 13.40 per cent lead and 14.90 per cent zinc, whereas samples (BR86-18 and -18A) from the upper zone of float boulders yielded up to 1.48 per cent lead, 5.78 per cent zinc, 23.6 grams per tonne silver, 0.33 gram per tonne gold, 187 grams per tonne germanium and 2 grams per tonne gallium (Assessment Report 15873). Also, at this time a sample (BR86-22) taken from a roadcut located in the southern end of the Black Rock No. 18 (L.15461) claim assayed 4.45 per cent zinc (Assessment Report 15873).
On the Jocelyn claim, located immediately to the west and covering Woodchuck Creek area, siliceous argillite and dolomite host fine pyrite along with rusty sheared or fractured zones with quartz veining. In 2012, three rock samples (HCR-1204, -1205 and -1206) yielded from 0.174 to 5.274 grams per tonne gold (Assessment Report 34410). No sample locations or descriptions were provided.
The area has been historically explored in conjunction with the nearby HB (MINFILE 082FSW004) past-producing mine. A former shaft, of unknown age, is reported to be located near the northwestern corner of the Black Rock 12 (L.14406) claim. Mineralization was first identified on the Black Rock claims in 1919 by J. Baxter. During 1951 through 1953, American Zinc Co. completed 34 drillholes, totalling approximately 5250 metres. In 1959, extensive trenching was performed on the north side of Sheep Creek in an area of sulphide-bearing boulders but failed to identify a bedrock source.
In 1979 and 1980, Mentor Exploration and Development completed programs of soil sampling and trenching on the area. In 1984, Greenwich Resources Inc. completed a program of rock and soil sampling, geological mapping and a ground electromagnetic survey. In 1986 and 1987, Source Resources, on behalf of St. Jame’s Minerals Ltd., conducted programs of prospecting, and geological mapping and rock and soil sampling the area. In 1990, St. Jame’s Minerals Ltd. completed a 7.0 line-kilometre ground magnetic and electromagnetic survey.
In 2011 and 2012, the area immediately west and covering Woodchuck Creek are was prospected and rock sampled as the Jocelyn claim.
