The Ruddock Creek property lies on the northwest flank of Frenchman Cap Dome within the Precambrian-Paleozoic(?) Shuswap Metamorphic Complex. The core gneisses of the dome lie beneath gently north-dipping metasedimentary rocks consisting of micaceous schist, calc-silicate schist and gneiss, with intercalated layers of marble. Pegmatite and associated medium-grained granitic rocks replace and impregnate the metasediments.
The structure in the area is dominated by repetitive folding, followed by faulting. Earlier phase 1 folds are isoclinal and obscure. Notably, one large isoclinal syncline with the main mineralized zone (E zone) at the hinge, trending 285 degrees and plunging 28 degrees, is recognized. Later phase 2 folds are more open and well-displayed. The axis of the phase 1 fold is essentially parallel to the axis of the phase 2 folds, with axial planes striking 020 to 030 degrees and dipping 20 to 30 degrees west.
Two general types of faulting occur in the area. The first type, along the G and M showings, are irregular but fairly continuous branching zones of mylonite striking north and dipping 20 to 50 degrees west. The second type are late block faults, the most important lying west of the E zone and displacing the main orebody down on the west. On the average, the fault strikes north and dips 58 degrees west.
Three mineralized areas, referred to as the E, F, G and M zone; the Creek and T zone (see MINFILE 082M 083) and the Q, R, V and U zone (see MINFILE 082M 082), occur as contorted layers and lenses several metres thick and are traced intermittently over a strike length of several kilometres within schist, siliceous calc-silicate gneiss, quartzite and marble.
The principal sulphides are sphalerite, pyrrhotite, galena, pyrite and minor chalcopyrite, locally associated with barite and fluorite. Very fine-grained sphalerite and pyrrhotite with minor galena and rounded quartz eyes are common. Equally common are layers containing medium-grained dark-brown sphalerite with interstitial quartz and scattered quartz augen. Galena and sphalerite also occur as scattered grains in marble, calcareous quartzite and fluorite.
In the sulphide layer, lenses of massive sulphides up to 1.5 metres thick are common. They are complexly folded within themselves on axes that plunge to the west parallel to the folds in the surrounding rocks. The folds in the sulphides, which are outlined by banding and by discontinuous layers of schist, gneiss and quartzite, are irregular in form and usually disharmonic.
The E zone (main showing), outcropping at 2300 metres elevation, is 240 metres long and widens from 15 metres across the strike at the east end to 60 metres across the open limbs at the west. The F zone, at 2000 metres elevation, occurs along the strike 600 metres southwest of the E zone. The F zone is traced for 180 metres on the surface. Five hundred metres west of the E zone, between 2240 and 2500 metres elevation, are a disjointed series of small mineralized showings referred to as the G zone. This zone continues 600 metres north to the M zone, which is at an elevation between 2470 and 2620 metres. The G zone measures approximately 10 by 150 metres.
Drill indicated reserves at Ruddock Creek are 5 million tonnes grading 2.5 per cent lead and 7.5 per cent zinc (Canadian Institute of Mining and Metallurgy Bulletin, April 1982, page 119).
Exploration on the Ruddock Creek property dates from the discovery of massive sulphide mineralization and the subsequent staking of the ground in 1960 by Falconbridge. Falconbridge conducted the most extensive exploration over the period 1961 to 1963. Core drilling was completed at the E zone and the G, M, T, Q, U and V showings. Cominco Ltd. optioned the property from Falconbridge in 1975, carrying out drilling and geophysics on the property.
Doublestar Resources Ltd. acquired Falconbridge’s 58.9 per cent interest in January 2000 and in August and September 2000 carried out a detailed mapping program on the property. In February 2001, Doublestar Resources Ltd. purchased the 41.1 per cent interest of Cominco Ltd. to hold a 100 per cent interest in the property. In March 2004, Cross Lake acquired an option on the property from Doublestar Resources Ltd. Cross Lake drilled 11 holes totaling 1839 metres in 2004, expanding the E zone to the west and north.
As of 2004, the E zone had been traced for an approximate length of 250 metres and a width of 150 metres.
Between 2004 and 2009 Selkirk Metals Corp. (owned subsidiary of Imperial Metals Corp.) conducted extensive exploration, including over 1 kilometre of underground development, and surface and underground diamond drilling totaling 25 688 metres.
In 2005, the property containing the occurrence was acquired by Selkirk Holdings. Selkirk completed electromagnetic surveys, a grid based UTEM, a magnetic survey, a soil geochemical survey and 3,245.4 metres of diamond drilling. New anomalies from surveying show further extent of the mineralized zones where no previous work had been conducted. The 2005 diamond drilling program found the E Zone mineralization continues to the west of the E fault remaining open to the west. The most significant zone of mineralization found measured 15.05 metres (14.15 metres true thickness) of massive sulphides grading 14.74 percent zinc and 3.11 percent lead (Chapman, P. (2007-06-12): National Instrument 43-101 Technical Report on the Ruddock Creek Property). Mineralization in other drill holes showed evidence of local thinning, folding or remobilization of sulphides through metamorphism.
In a 2006 drilling exploration program by Selkirk Metals Corp., a total of 12,808.48 metres of core were drilled across 35 holes within the E Zone, 1,073.71 metres in 10 holes at the Creek Zone and 857.47 metres between 3 holes in the Oliver Creek area (Chapman, P. (2007-06-12): National Instrument 43-101 Technical Report on the Ruddock Creek Property). Three drill sites focused on the new anomalous zones suggested by the 2005 UTEM and airborne surveys. One found a pyrrhotite bearing horizon, similar to the unit underlying the mineralization in Zone E. Although no significant lead or zinc mineralization was found. The other two drill holes on anomalies found a mafic volcanic unit with no significant lead or zinc mineralization. The drilling program overall showed mineralization of the E Zone forms a planar sheet of massive sulphides with dip and plunge approximately 45 degrees to the northwest and 40 degrees to the west, respectively.
In 2007, Selkirk Metals Corp. conducted a drilling program on the E Zone totaling 2,366 metres between 9 holes.
In 2008, an extensive underground drill hole program was completed by Atlas Drilling Ltd. for Selkirk Metals Corp. Significant results from the E Zone included but are not limited to, 22.56 metres of 11.7 percent zinc and 2.27 percent lead in hole RD-152, and 15.29 metres at 12.19 percent zinc and 2.18 percent lead in hole EUG-08-021 (Chapman, J., Simpson, R. (2009-07-15): Mineral Resource Estimate of Ruddock Creek Deposit).
Imperial Metals Corp. released resource estimates in 2009 which reported indicated resources of 2 338 000 tonnes grading 7.79 per cent zinc and 1.61 per cent lead and inferred resources of 1 492 000 tonnes grading 6.50 per cent zinc and 1.26 per cent lead using a 4.0 per cent Zn+Pb cut-off grade. (V STOCKWATCH, July 20, 2009).
In 2010, Selkirk Metals Corporation conducted an underground drilling program to extend the E Zone decline. Three holes totalling 461 metres.
In 2011 Selkirk Metals continued extension of the E Zone decline alongside conducting an underground and surface drilling program focused on Creek, Q, and V Zones. The E Zone decline was extended to 1,291 metres below the surface.
In early 2012, Imperial Metals Corp. released an updated NI 43-101–compliant inferred and indicated resource estimate which reported indicated resources of 4 654 000 tonnes grading 6.77 per cent zinc and 1.38 per cent lead, and inferred resources of 5 382 000 tonnes grading 6.69 per cent zinc and 1.31 per cent lead using a 4.0 per cent Zn+Pb cut-off grade (Press Release, Imperial Metals Corp., March 14, 2012).
In 2012, Imperial Metals Corp. completed an exploration program which included surface diamond drilling on the V (MINFILE 082M 082) and Creek (MINFILE 082M 083) zones, underground diamond drilling on the lower E zone and an additional 69 metres of underground development for the collection of a metallurgical bulk sample. In total, 18 holes were completed in the V zone, seven holes in the Creek zone and 26 holes from underground, for a total of 10 081 metres of surface drilling and 5843 metres of underground drilling. The 2012 underground diamond drilling program concentrated on the updip extensions of the lower E zone.
In 2012, Selkirk Metals Corporation released an updated mineral resource estimate for the E Zone and the Creek Zone. The E Zone was estimated at a cutoff grade of lead plus zinc at 4.0 percent for 4,654,000 tonnes indicated grading 6.77 percent zinc and 1.38 percent lead, and 3,703,000 tonnes of inferred at 6.56 percent zinc and 1.24 percent lead (Miller-Tait, J., Simpson, R. (2012-03-01): Technical Report on Ruddock Creek Lead-Zinc Project).