The Armstrong occurrence is situated northwest of Erie Lake, approximately 1.2 kilometres north of Highway 3 and 3 kilometres west of Salmo.
The area is underlain by Early Jurassic Rossland Group rocks intruded by phases of the Middle Jurassic Nelson Batholithic Suite. Within the Rossland Group, the Archibald Formation—a sequence of fine to coarse sediments—is overlain by the volcanic rocks of the Elise Formation and the mainly fine-grained clastic rocks of the Hall Formation. The Archibald Formation ranges from interlayered argillites and siltstones (exposed at the Maybee vein) to dark, laminated rusty argillites interlayered with occasional augite phyric flows marking a gradational contact with the overlying Elise Formation. The Elise Formation is subdivided into a basal unit of mafic flows and flow breccias overlain by a thick accumulation of intermediate pyroclastic rocks. To the south, exposures of the Lower Elise contain massive augite-phyric flows, flow breccias and heterolithic to mafic clast-dominated volcaniclastics interbedded with well-layered, mafic water-lain tuff beds. To the north, the Elise is dominated by well-layered fine to lapilli tuffs interlayered with dark graphitic argillite and dark grey argillaceous siltstone.
To the north, the southern edge of the Bonnington Batholith, part of the Nelson Plutonic Suite, is exposed, as is a small granitic stock in the valley to the south. Exposures of the Bonnington Batholith consist of potassium-feldspar porphyritic to locally massive granodiorite cut by felsic dikes.
Several generations of faulting have been recognized in the area. North-trending, east-verging thrust faults occurring to the south and southeast are cut by Cretaceous and Middle Jurassic plutons. Parallel, north-northeast–trending faults occurring to the south cut earlier folds and are cut and sealed by Jurassic plutons. Steeply dipping, northwest-trending extensional faults running through the centre of the Sadarsa property cut both earlier structures and Jurassic plutons.
At the Armstrong occurrence, granite of the Middle to Late Jurassic Nelson Batholith contains four widely spaced, parallel, silicified fracture zones that strike 305 degrees and dip about 50 degrees northeast.
The principal working consists of a silicified zone or vein that is coincident with and on the footwall of a basic dike approximately 0.7 metre thick. Galena, sphalerite, pyrite and arsenopyrite are sparsely disseminated throughout the silicified zone and stibnite is streaked on fracture surfaces. The mineralized fracture zone is in the order of 2 metres thick. A 30-centimetre sample assayed 0.69 gram per tonne gold, 459.43 grams per tonne silver, 3.7 per cent lead and 0.5 per cent zinc (Minister of Mines Annual Report, 1928, page 338).
Prior to 1902, the Transvaal and Zambesi Mining Company conducted development work on the Armstrong claim group, consisting of the Armstrong, Erie and Black Knight claims. By 1902, four adits had been driven on the claim group. The property was dormant from 1902 until 1928, when the claims were acquired by S.E. Coulter and P. Coulter. The old tunnels were cleaned out and the trail to the property was opened up. The workings, situated on the Black Knight claim, consisted of open-cuts and four tunnels. The tunnels developed four widely separated silicified fractured zones in granite. Minor underground development took place at that time. A 907-kilogram sample was excavated and sent for processing. The sample returned $22 CAD worth of silver (Assessment Report 18830, page 4).
In 1939, Law-Mac Mines Limited operated a gold and silver mine on the Salmo-Trail road near Erie. That same year, Law-Mac Mines completed approximately 557.784 centimetres (18.3 feet) of underground development, shipped 13 tonnes of ore for processing and recovered 31 grams of gold and 871 grams of silver (Ministry of Mines Annual Report, 1939, page 84).
In 1978 and 1979, Salmet Resources Corporation staked the Dan, Dan 2 and Dan 3 claims over the southern half of the modern Sadarsa property. The claims were held as part of the Silverhorn property. In 1980, Salmet Resources conducted a program of geochemical sampling, geophysical surveying and trenching on the Silverhorn claims to the immediate east.
The first record of exploration on the Sadarsa property was in 1981 on the Key claim to the west of the Dan and Armstrong claim groups. The Key claim covered an area containing the Meadows occurrence (MINFILE 082FSW268). Rick Wierzbicki carried out a limited molybdenum exploration program on the property, collecting two geochemical samples.
In 1983, Taiga Consultants Limited, on behalf of Rex Silver Mines Limited, conducted reconnaissance mapping, prospecting, sampling, soil geochemistry and ground geophysical surveying on the ORC claims to the north. Five samples were collected from the Erie Creek showing.
In 1989, a very low-frequency electromagnetic ground geophysical survey was conducted over the DC, Bear and Poogy claims to the immediate west of the historic Armstrong claim group (MINFILE 082FSW267). Following this survey, 117 soil samples were collected between 1989 and 1990. In 1990, a grid was established over the southeastern portion of the claim group. A total of 5.2 line kilometres of ground geophysical surveying were completed and 66 soil and eight rock samples were collected and sent for analysis.
In 1989, the northeastern portion of the modern Sadarsa property was staked as the Erie Creek property. Between 1989 and 1990, Desert Gold Resources Incorporated conducted an exploration program of geological mapping, geophysical surveying and soil, silt and rock geochemistry on the Erie Creek claim group.
In 1990, a program of prospecting, mapping, showing and outcrop sampling and geophysical surveying was completed on the Shamrock claim group by claim owners R. Bourdon and C. Pittman. A total of 29 samples were collected in the immediate vicinity of the Shamrock and Maybee veins.
That same year, R. Jordan conducted a mapping and prospecting traverse across the Sherman claim to the immediate east of the Armstrong claim group. The following year, Jordan followed up the mapping and prospecting program by collecting 23 soil samples on the Sherman claim and 35 samples on the RR claim to the northeast of the Armstrong claim group.
In 2007, D. Lavoie staked the Sadarsa claim group over an area encompassing the Armstrong claim group. That same year, prospector Tom Kennedy conducted a small rock geochemistry program on the property, collecting 42 rock samples. As a follow-up to the rock sampling program, Robert Klewchuk Limited was commissioned to conduct a soil sampling program on the property in 2008. Samples were collected over two grids—one to the southwest of the Erie Creek showing in the northern portion of the property and the other slightly north of and between the Meadows (MINFILE 082FSW268) and Shamrock occurrences in the southwestern portion of the property. Between 2009 and 2010, Kennedy conducted another rock geochemistry program in the southeastern corner of the property. Later in 2010, an additional nine samples were collected from the southwestern corner of the property from an area between the Meadows (MINFILE 082FSW268) and Armstrong occurrences.
In 2011, Trygve Hoy, on behalf of Kootenay Gold Incorporated (also referred to as Kootenay Silver Incorporated), conducted a short program of geological mapping and sampling on the property. Samples were collected from the Meadows occurrence, Shamrock vein, Maybee vein and a newly discovered vein exposed approximately 500 metres west of the Armstrong occurrence. That same year, Tom Kennedy collected 65 rock samples across the southern portion of the Sadarsa property.
In 2012, Kennedy carried out a 34-sample rock geochemistry program over the Shamrock zone. Sampling was focused in the area of the Shamrock vein and to the south of the Maybee vein.
In 1928, a 30-centimetre sample assayed 0.69 gram per tonne gold, 459.43 grams per tonne silver, 3.7 per cent lead and 0.5 per cent zinc (Minister of Mines Annual Report, 1928, page 338).
The most significant result from the 2007 rock sampling program was sample ER07-6, which returned 0.67 gram per tonne gold and 31.6 grams per tonne silver (Assessment Report 30175, page 7).
