This property lies on the summit between Sheep & Lost Creeks, about 11 kilometres southeast of Salmo. Although the Emerald has in recent years been a tungsten producer (082FSW010), its early history as a lead-zinc producer is mentioned here because the Jersey workings were later extended into Emerald ground (082FSW310) and production figures for the two have not been recorded separately.
Production of lead-zinc ore from the Emerald was begun in 1906 by the owner, J. Waldbesen. In 1917 Iron Mountain Ltd. was formed to operate the mine and a 25 ton mill was put into operation. The Emerald was a small but steady producer of lead- zinc ore from 1906 to 1925.
A small amount of shallow development work was done on the Jersey claim from 1916 to 1919 and some ore was shipped, however the main ore deposit was not discovered at this time.
Canadian Exploration Ltd., while operating the Emerald tungsten mine, carried out an extensive diamond drilling program on the Jersey during 1948 and a large tonnage of lead-zinc ore was outlined. During 1948-49 the Emerald tungsten operation was closed down and the mill, beside the Nelson-Nelway Highway, was converted to a lead-zinc operation and production from the Jersey began in March 1949. The mine has operated continuously since that time, development work being done on all seven ore zones. Track mining has been used in A, C, and D zones and trackless mining in A, D, E, F, and G zones. The A zone has been developed from the south end of the Jersey zone to a point north of the Emerald, a distance of 1524 metres.
Ore reserves as of April 1, 1965 are reported at 671,075 tonnes grading 1.2 per cent lead and 4.1 per cent zinc.
The Jersey mine is a Kootenay Arc-type sedimentary exhalative deposit that occurs in the Kootenay Arc within what is called the Mine Belt, an area of carbonate hosted lead-zinc deposits associated with Lower Cambrian limestones of the Reeves Member (Laib Formation) and its equivalent, the Badshot Formation.
The dominant structure of the Mine Belt is the north trending Jersey anticline, an isoclinal fold whose axial plane dips 45 degrees to the east. The Jersey orebodies are gently dipping tabular or lenticular bands of sulphide which lie on the normal limb of the anticline parallel to the banding in the sediments. The orebodies trend 015 degrees and plunge 10 degrees southerly over a distances up to 1800 metres. The maximum east-west width is 600 metres.
The Reeves limestone is 120 to 150 metres thick in the mine area. Lead-zinc mineralization, occurring mainly in dolomite near the base of the Reeves Member, varies from 8 to 30 metres in thickness. The limestone and dolomite varies from a blue-green banded type to a white massive type. The dolomites are typically finer grained than the limestones. The Truman Member of the Laib Formation conformably underlies the Reeves Member, and forms the mine footwall rocks. This member consist of hard, dense, reddish green skarn and a brown argillite. The skarn is characterized by tungsten and minor molybdenum mineralization. The mine is bound on the east side by the Argillite (Iron Mountain) fault which down faults younger beds on the east side. The Dodger and Emerald stocks of the Middle to Late Jurassic Nelson Intrusions underlie the mine area.
Secondary, symmetrical anticlinal and synclinal fold structures along the normal limb of the anticline have been used to delineate ten ore zones (A to J) within the deposit. Mineralization occurs more strongly in the fold troughs relative to the fold crests. The amplitude of these folds rarely exceeds 15 metres and their axis trends slightly east of north. Numerous post-ore faults and lamprophyre dykes crosscut the stratigraphy.
Five ore bands, ranging in thickness from 0.3 to 9 metres are recognized in the mine. These bands in order of stratigraphic sequence are: 1) Upper Lead Band; 2) Upper Zinc Band; 3) Middle Zinc Band; 4) Lower Zinc Band; and 5) Lower Lead Band. Ore mineralization consists of fine-grained sphalerite and galena with pyrite, pyrrhotite and minor arsenopyrite. Cadmium is associated with sphalerite, silver with galena. Iron content of the sphalerite is low (about 6 per cent). The overall grade of the deposit is about 3.7 per cent zinc and 1.2 per cent lead.
In the A zone the ore bands are very close together and frequently have been mined as a unit up to 24 metres thick. Throughout the remainder of the mine these bands have been mined separately or in combinations.
The Lower Jersey zone is a zinc and lead enriched dolomite horizon located about 60 metres below the previously mined Jersey orebody. The zone was recognized in 1996 when a new mine model was prepared on the basis of surface and underground geology as well as two underground drillholes drilled prior to the mine's closure. Within the area previously tested, the widest mineralized intercept is 9 metres and the best single intersection graded 8.1 per cent zinc and 3.8 per cent lead across 1 metre (George Cross News Letter No. 27, February 7, 1997).
The Bismuth Gold zone is a flat lying, gold-enriched horizon which overlies and trends parallel to the east limb of the former Jersey deposit. Two holes drilled into this zone in 1996 intersected a flat lying, 9-metre thick, pyrrhotitic horizon with gold grades ranging from 2.0 to 8.3 grams per tonne. A review of the mine records for drilling completed in the 1940s and 1950s indicates this gold-rich sulphide zone was intersected in surface and underground drillholes over a north-south distance of 1000 metres. These records suggest the body ranges from 1 to 18 metres in thickness (George Cross News Letter No.27, February 7, 1997).
The Jersey mine commenced milling of lead-zinc ores in 1949 and continued until 1970 when operations ceased due to depletion of ore reserves. The mine produced about 6.4 million tonnes of ore from which 115 thousand tonnes of lead, 263 thousand tonnes of zinc and 21.5 thousand kilograms of silver were recovered.
Sultan Minerals Inc. explored and drilled the area in 1996 (1700 metres in 16 holes) and 1997 (1204 metres in 16 holes underground). The best intersection was 2.65 per cent zinc and 4.62 per cent lead over a 5-metre core length (4 metres true thickness). Sultan had plans for more work in 1999.
In 2008, Sultan reported measured and indicated resources of 2.3 million tonnes grading 0.372 per cent WO3 and 440,000 tonnes grading 0.103 per cent MoS2(N Miner Sept 1, 2008).
In 2009 Sultan reported resources for the Tungsten Zone:
(Press Release January 21, 2009 http://www.sultanminerals.com)
Category Amount (tonnes) WO3 (%)
Combined Measured and Indicated 2,467,000 0.358
Inferred 2,105,000 0.341
In 2010, Sultan reported an Indicated resource of 4.83 million tonnes grading 1.04 per cent Pb and 2.60 per cent Zn and an Inferred resource of 15.36 million tonnes grading 1.00 per cent Pb and 2.18 per cent Zn, using a cut-off grade of 1.5 per cent combined Pb-Zn (Press Release, Sultan Minerals Inc. March 1, 2010).