Castle Mine Project
The only permitted underground asset in the Cobalt camp
The past-producing silver-cobalt Castle Silver Mine property is located 85 km northwest of Cobalt, Ontario, which is the centre of the historic Silver Cobalt Mining Camp.
When acquired, the property size was 2,815 hectares, but in recent years the size has been expanded primarily to the north to a total of 7,800 hectares (78 km sq).
Technical Report
NI 43-101 Technical Report on the Castle Mine Property was published in 2015
STRATEGY
First Ever Resource Estimate
The mining approach taken at the Castle Mine was to drill from underground to locate the high-grade silver veins and then use drilling to continue to locate and follow the veins. Each vein could extend many hundreds of meters and could vary in silver grade along the way.
Exploration
Much of the cobalt in the Castle Mine remains untouched since there was no interest at the time.
Production
Silver-cobalt mining economics could be enhanced by metal credits such as nickel and gold.
RESULTS
Phases of Development
Data allows interpretation of upper and lower contacts of the Nipissing diabase sill based on surface geology, underground mapping and historic drill hole information. Silver mineralization is historically spatially associated with the upper half of this intrusive body.
Phase 1
Selected drilling and sampling in Level 1 showed grades as high as 5.2% cobalt, 5.3% nickel and 13,208 g/t silver.
Phase 2
Underground drilling in 2019 in Level 1 of the Castle Mine discovered high-grade gold (22 grams/tonne) along with high-grade silver, cobalt and nickel.
History
The Castle Mine site operated at various times between 1917 and 1989. Production totalled 292,686,672 grams (9,410,095 oz.) silver and 376,053 lbs. cobalt from the No. 3 shaft.
The property still has all three existing shafts, and totals 78 square kilometres where only silver in a small area was targeted, leaving substantial discovery potential.
Geology
Management considers the property to have the potential to host significant cobalt plus high grade silver.
There is also a strong likelihood future cobalt mining economics will be enhanced by metal credits such as nickel, silver and others. Drilling and sampling underground at Castle showed grades as high as 5.2% cobalt.
BACKGROUND
Ore Grades Over Time
In the Greater Silver-Cobalt Camp, silver and cobalt are typically found together in varying grades in quartz and calcite veins in or near the Nipissing Diabase, while gold and copper tend to be found in the Archean Volcanic rock. Historical records show that the Castle Mine’s average ore grades were:
1923 - 1930
25 oz/ton silver and 1 lb/ton cobalt.
1979 - 1989
26 oz/ton (812 grams/tonne) silver.
Extended period of time
85 oz/ton (2,650 g/t) according to local reports.
DATA
Integration Of Sources
The company currently has access through an adit to Level 1 underground of the Castle Mine, which has in total 11 levels where mining occurred extending down to a depth of 259 meters below the surface. The terrain details are from a drone survey completed in the spring of 2016 that provided current and accurate surface elevation. From that other layers were added as follows:
Pink lines
Underground workings at Level 1 (depth of 79ft or 24m)
Yellow lines
Exploration holes drilled from Level 1
Blue lines
7 of 12 surface holes drilled by the company in 2011
Cross Section of Underground
Longitudinal section through Castle No.3 workings. View looking North. Mining occurred on 11 different levels during the 1900s down to approximately 850 feet (259.1m)
Cross Section
Cress Section looking Northeast through the Castle mine workings. Image shows IP data along Line0E from a 2011 induced polarization (IP) geophysical survey. Colour gradation for IP indicates High Resistivity (blue) to Low Resistivity (red). In this section, the blue roughly correlates with the diabase intrusive unit that is already well defined from underground drilling and workings.
