Work History

Staked in Jun/68 by P. Risby as Cab cl 1-32 (Y25386), which were optioned by Atlas Explorations Limited and Mitsui Mining & Smelting Company Ltd and transferred to Atsui Mining Corporation Ltd. After Atsui mapped and sampled in 1968-70, in a joint venture with Dynasty Exploration Ltd, the property was transferred to a new company, Risby Tungsten Mining Ltd, and was optioned in Apr/70 by Caltor Syndicate (Rayrock Mining Limited, Ashland Canada Oil Ltd and Canadian Industrial Gas & Oil Company Ltd). Caltor drilled 8 holes (1,086 m) on the No. 2 zone during 1971 to earn a 55% interest in Risby Tungsten. Atlas changed its name to Cima Resources Limited in 1974 and Dynasty changed to Cyprus Anvil Mining Corporation in 1975. Cima performed linecutting in 1976 and trenching and sampling in 1977. In 1978, Risby Tungsten acquired the majority interest, enlarged the property and conducted more mapping, sampling and trenching.

The property was optioned in 1979 by a joint venture between Hudson Bay Mining & Smelting and Minorco Canada Limited, which performed mag and EM surveys and drilled 16 holes (1,626 m) on the No. 2 Zone in 1979, 15 holes (2,162 m) in 1980 and 9 holes (2,183 m) in 1981 and mapped in 1982. Risby Tungsten changed its name to Imperial Metals Corporation in 1981.

Restaked as Risby cl 1-4 (YB46673) in April/94 and the Johns cl 1-2 (YB54521) in Sept/94 by R. Berdahl. Berdahl added Gold cl 1-2 (YB66240) on the southwest boarder of the Risby in Sept/95. In Mar/01 Sur American Gold Corporation optioned the Risby, Johns and Gold claims from Berdahl. In 2006, Playfair Mining acquired 100% ownershp of the property from R. Berdahl. In 2006, a total of 754.88 m of diamond drilling was completed in six holes. Playfair Mining completed seven diamond drillholes for a total of 1,600 m in 2008.

A 43-101 compliant mineral resource estimate was released for the Risby deposit in 2007 (Wardrop, Sept 2007, for Playfair Mining Ltd). An updated 43-101 compliant resource estimate was prepared by PEG Mining Consultants Inc.(May 29, 2009).

Capsule Geology

The occurrence is located southwest of the Tintina Fault Zone in the Cassiar terrane (Platform). The Cassiar terrane is a curvilinear shelf which formed, between mid-Cambrian to Silurian time, roughly parallel to the western edge of the North American craton, but separated from it by the Selwyn Basin. Shallow water deposition on the platform continued until Late Devonian time. Block faulting and local uplift during the Late Devonian and Mississippian resulted in deposition of carbonaceous shale and chert pebble conglomerate in the Selwyn basin and across the Cassiar terrane.

The occurrence area covers a portion of the Lower Cambrian Rosella assemblage/suite (unit ICR) composed of limestone, argillaceous limestone, fossiliferous limestone and lesser marble, calc-silicate, calcareous phyllite, minor schist and the Ingenika assemblage/suite (unit PCI4) composed of siliciclastics, minor limestone schist, minor amphibolite and marble. The Rosella and Ingenika assemblages/suites are intruded by a middle Cretaceous quartz monzonite pluton of the Cassiar Suite (unit mKqC) (Gordey and Makepeace, 1999).

The skarn showings located on and near the margins of the medium-grained quartz monzonite are developed in limestone found interbedded with quartzite and quartz-biotite schist and limestone (Darney, Mar/69).

Mineralization found to date consists of two gossanous diopside-garnet skarn zones in Lower Cambrian carbonate that strike almost perpendicular to each other. The No. 1 zone is structurally complex and has been traced on surface over an area of 250 m by 75 m in a roof pendant (MIR 1969-70, 1972). It has a high pyrrhotite content with a little chalcopyrite and the pyrrhotite is locally auriferous with rock grab samples yielding up to 2.312 g/t Au (Berdahl, 1995b).

The larger No. 2 zone, which strikes north and dips east parallel to the intrusive contact, is mineralized over a length of 1,200 m and has a low sulphide content. It consists of two separate bands 1.5 to 4.5 m thick separated by 3 - 10 m of interbedded quartz biotite schist and local sills of quartz monzonite intrusive (Darney, 1969). Surface sampling indicated grades between 0.5 and 1.0% WO₃. The more persistent lower band extends for a strike length of 660 m and a vertical extent of 350 m. The best intersections were 3.4 m grading 1.3% WO₃ in the lower skarn and 3 m grading 1.4% WO₃ in the upper. The upper zone also gave an intersection of 0.7% over 14.0 m. In Jul/82 reserves were estimated at 2.7 million tonnes grading 0.81% WO₃.

Rock samples collected by Berdahl (1995a,b) from the two zones were elevated and moderately anomalous in bismuth (up to 0.1%), arsenic (up to 13%) and antimony (up to 168 ppm).

Diamond drilling in 2006 intersected 6.49 m @ 1.09% WO₃ in the Upper Skarn and 5.37 m @ 0.49% WO₃ in the Lower Skarn in hole RT06-05 (cut-off grade of 0.30% WO₃).

A 43-101 compliant mineral resource estimate was released for the Risby deposit in 2007 (Wardrop, Sept 2007). The study reported an Inferred Resources of 6,385,000 tonnes at 0.462% WO₃ (0.20% cut-off grade). A highlight intercept from the 2008 drilling is 4.43 m of 0.991% WO₃ in hole RT08-51.

An updated 43-101 compliant resource estimate was prepared by PEG Mining Consultants Inc.(May 29, 2009) which combined 2008 drill results with the 2007 resource estimate. The Inferred Resource as of May 14, 2009 is 8.537 million tonnes @ 0.475% WO₃ (cut-off grade of 0.2% WO₃).
 

61.859720

-133.384440

Assessment Reports that overlap occurrence

Report Number	Year	Title	Worktypes	Holes Drilled	Meters Drilled
094598	2006	Summary Diamond Drill Hole Report on the Risby Tungsten Project	Diamond - Drilling	6	754.88
093449	1995	General Prospecting Report on the Risby Gold Project	Rock - Geochemistry, Prospecting - Other
093358	1994	General Prospecting Report on the Risby Gold Project	Rock - Geochemistry, Prospecting - Other
091133	1979	Assessment Report Diamond Drilling Program	Diamond - Drilling	16	1625.80
060016	1969	Geochemical Report Cab Claim Group	Silt - Geochemistry, Soil - Geochemistry
060017	1969	Geological Report Cab Claim Group	Detailed Bedrock Mapping - Geology
018891	1968	Geological and Geochemical Report Cab Mineral Claim Group	Rock - Geochemistry, Soil - Geochemistry, Bedrock Mapping - Geology