Overview
Status | Inactive / Suspended |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Shrinkage stoping
- Longhole stoping
|
Processing |
- Gravity separation
- Flotation
- Carbon in leach (CIL)
- Cyanide (reagent)
|
Mine Life | 4 years (as of Jan 1, 2011) |
The McGarry mineral property was pledged as security for a loan payable. |
Source:
The McGarry property is owned 75% by Kerr Mines Inc. and 25% by Jubilee Gold Inc.
August 20, 2018, Orefinders Closes McGarry Mine & Larder-Lake Project Acquisition. Orefinders has delivered the purchase consideration to Kerr Mines Inc.(“Kerr”) being 8 million of its common shares. Additionally, Kerr will receive 440,248 shares in PowerOre Inc. as the Kerr/Orefinders transaction was agreed to prior to Orefinders Plan of Arrangement with PowerOre. The 8 Million Orefinders shares are subject to a lock up agreement with Kerr and are scheduled to be free trading over a two-year period.
Deposit Type
- Breccia pipe / Stockwork
- Vein / narrow vein
- Sediment-hosted
Summary:
Gold-bearing zones in the Virginiatown camp area commonly occur as repetitive tabular lenses within veined green carbonate rock and pyritic cherty mudstones. In the carbonates, erratic and often coarse gold in native form occurs in contained quartz veining and is locally referred to as “green carbonate ore”. In the cherty mudstones, gold generally occurs in crystal intergrowth with disseminated pyrite and is locally referred to as “flow ore”. There are other deposit types such as graphite-rich and within altered albitite dikes but these are minor and local.
Brecciated stockwork zones of green carbonate rock also constitute an important deposit type in the area. In these, native gold occurs at quartz vein contacts and is particularly strongly associated with flat or low angle veining. Typically, such zones on the adjoining Kerr Addison mine property could be up to 100 ft in thickness and several hundred feet in length and vertical extent.
Because of the erratic distribution of gold within them, the stockwork zones are very difficult to identify, and were often recognized in drilling at the Kerr Addison mine by the presence of 20 to 30 percent vein quartz carrying a few flecks of native gold. They were generally mined on a bulk shrinkage basis. The only well identified occurrence of this style of mineralization at the McGarry Project is on the 2250 Level in the gold zone encountered in the 600W cross-cut in the 260N Zone.
An important deposit type at Armistice is “pyritic mudstone” with varying amounts of quartz. It is difficult to determine the primary nature of these pyritic mudstone units. They may be inter-volcanic, shallow marine\ accumulations of sediments derived from the volcanics with the sulphides and gold originating from gases and fluids emanating from fissures related to the volcanic activity.
Pyritic mudstone units (“flow ore”) constitute an important gold-bearing zones at McGarry. Pyritic mudstone units appear to follow distinct formational horizons. Gold in such zones occurs mainly in intergrowth with pyrite and only sparingly in native form. The pyrite is medium to coarse grained and occurs in the cherty mudstones in disseminations varying from 1 to 25 percent of the rock volume. Minor quartz veining and silicification is commonly in evidence. Arsenopyrite and occasionally chalcopyrite may be present.
A second gold-bearing mineralization type has similarities to the “green carbonate ore” at Kerr Addison. This style of mineralization was of lower grade at the Kerr Addison than the “flow ore” type. The pyrite content is in the 1 to 25% range. Gold distribution is probably the same as in the pyritic mudstones but has been locally concentrated into larger grains so that visible gold is more common. The overall gold distribution appears to have been dispersed over a larger and more poorly defined volume which lowers the average grade over mineable widths and lengths and, as a corollary, increases the internal dilution within potential stoping areas.
Mining Methods
- Shrinkage stoping
- Longhole stoping
Summary:
Shrinkage and longhole mining, and a hybrid combination of these methods, are applicable to this project.
In shrinkage stoping, the ore is mined out in successive flat slices, working upward from the level. After each slice is blasted down, enough broken ore is drawn off from below to provide a working space between the top of the pile of broken ore (“muck”) and the back of the stope. Usually about 40% of the broken ore will have been drawn off when the stope has been mined to the top. After the stope has been mined to the top, the remaining 60% of the ore in the stope is drawn down until the stope is empty. Shrinkage stoping is a method often applied to the mining of narrow veins and has been widely used in the Abitibi gold district. There are variations on the method of access to the top of the stope, to the method of drawing off the broken ore and to the drill/blast techniques for bringing down each successive slice of ore.
Processing
- Gravity separation
- Flotation
- Carbon in leach (CIL)
- Cyanide (reagent)
Source:
Summary:
A review of metallurgical test shows that recoveries of 95% of the gold has been demonstrated using conventional carbon-in-leach processes. In addition, test work has shown that recoveries of 44 to 65% of the gold in 6 to 16%, respectively, of the weight of the mill feed has been demonstrated by gravity or gravity/flotation techniques alone. The gravity testing has been done using shaking tables only. No test work with centrifugal concentrators has yet been done. These results warrant continued testing to optimize non-leach gold recovery options.
Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Gold
|
Recovery Rate, %
| ......  |
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Projected Production:
Commodity | Units | LOM |
Gold
|
oz
| 108,700 |
Operational Metrics:
Metrics | |
Total tonnes mined, LOM
| 752,500 tons * |
* According to 2011 study.
Reserves at June 30, 2014:
Category | Tonnage | Commodity | Grade | Contained Metal |
Indicated
|
492,000 tons
|
Gold
|
0.25 oz/ton
|
123,000 oz
|
Inferred
|
172,000 tons
|
Gold
|
0.17 oz/ton
|
30,000 oz
|
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