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CHIRANO GOLD MINE
Chirano Resources
The revised open pit and underground resources at Chirano as at December 31, 2009 are as follows:
Resource Estimate December 2009 |
| Resource Category |
Sector |
Cut Off (g/t) |
Tonnes (Mt) |
Au (g/t) |
Ounces (Moz) |
| Measured |
Open Pits |
1.0 |
16.1 |
1.88 |
0.98 |
| |
Akwaaba UG |
1.5 |
0.7 |
4.32 |
0.10 |
| Indicated |
Open Pits |
1.0 |
11.6 |
1.69 |
0.63 |
| |
Akwaaba UG |
1.5 |
7.0 |
5.23 |
1.18 |
| |
Paboase UG* |
1.5 |
7.7 |
4.19 |
1.04 |
| |
Stockpiles |
|
3.4 |
1.23 |
0.14 |
| Total Measured and Indicated |
|
|
46.6 |
2.71 |
4.07 |
| Inferred |
Open Pits |
1.0 |
5.6 |
1.7 |
0.3 |
| |
Akwaaba UG |
1.5 |
0.8 |
2.7 |
0.1 |
| |
Paboase UG* |
1.5 |
1.2 |
4.4 |
0.2 |
| |
Suraw UG |
2.0 |
2.0 |
3.9 |
0.3 |
| Total Inferred |
|
|
9.6 |
2.7 |
0.8 |
*May 2010
- Numbers may not add exactly due to rounding
- Open pit Mineral Resources are reported above a 1g/t cut off inclusive of ROM/low grade stockpiles. Gold grades for the reported open pit resource have been determined using Multiple Indicator Kriging (MIK) based on block dimensions of 12.5m (east) x 25m (north) x 6m (elevation) and using a selective mining unit of 2m (east) by 5m (north) by 2.5m (elevation). Gold estimation and model blocks were constrained within geologically derived wireframes. Due to the homogenous nature of the data no top cut has been applied to the resource data prior to estimation. It is observed that higher values in the dataset have little influence on the grade of the deposit.
- Akwaaba Underground Resources are reported above a 1.5 g/t cut off and below the 2212mRL which is the base of the Akwaaba open pit. Gold grades for the reported underground resource model have been determined using Ordinary Kriging (OK) with grades interpolated into parent blocks with dimensions of 5m (east) by 25m (north) by 10m (elevation). Gold estimation and model blocks were constrained within geologically derived wireframes.
- Paboase Underground Mineral Resources are reported above a 1.5g/t cut off and below the 2235m elevation, approximately and above the elevation of 1525m. Gold grades for the reported underground resource model have been determined using Ordinary Kriging (OK) with grades interpolated into parent blocks with dimensions of 2m (east) by 10m (north) by 25m (elevation). Gold estimation and model blocks were constrained within geologically derived wireframes.
- Suraw Underground Resource is reported above a 2.0g/t cut off and below 2224m elevation which is the base of current open pit design. Gold grades for the reported underground resource model have been determined using Ordinary Kriging (OK) with grades interpolated into parent blocks with dimensions of 2m (east) by 25m (north) by 25m (elevation). Gold estimation and model blocks were constrained within geologically derived wireframes.
- Open Pit and Akwaaba Deeps Mineral Resources are inclusive of Ore Reserves
The independent Resource estimate reported was undertaken by Nic Johnson (Member of the Australian Institute of Geoscientists) of Hellman and Schofield Pty Ltd with more than five years experience in the use of geostatistics for estimation of recoverable resources in gold deposits. For the purpose of reporting under National Instrument 43-101 Mr. Johnson is regarded as a Qualified Person.
Chirano Reserves
The Company’s consultants, AMC Consultants, have re-estimated Mineral Reserves for the Chirano mine, which are reported below as at 31 December 2009:
Reserve Estimate December 2009 |
Area |
Proven |
Probable |
Total |
|
Tonnes (MT) |
Au (g/t) |
Ounces (Moz) |
Tonnes (MT) |
Au (g/t) |
Ounces (Moz) |
Tonnes (MT) |
Au (g/t) |
Ounces (Moz) |
Open Pits |
16.4 |
1.55 |
0.82 |
4.7 |
1.34 |
0.20 |
21.2 |
1.50 |
1.02 |
Akwaaba |
- |
- |
- |
8.9 |
3.91 |
1.11 |
8.9 |
3.91 |
1.11 |
Paboase* |
- |
- |
- |
7.9 |
3.64 |
0.92 |
7.9 |
3.64 |
0.92 |
Stockpile |
3.4 |
1.24 |
0.14 |
- |
- |
- |
3.4 |
1.24 |
0.14 |
Total |
19.8 |
1.50 |
0.96 |
21.5 |
3.24 |
2.23 |
41.3 |
2.40 |
3.19 |
*May 2010
- Numbers may not add correctly due to rounding
Open Pits
- The Mineral Reserve estimate was made using a gold price of US$800
- Various cut-off grades were used to estimate the Open pit inventories and form the Mineral Reserve depending on material type and location with an average breakeven cut-off drade in the range of 0.60g/t and 0.65 g/t.
Akwaaba
- The Underground Mineral Reserve is based on SLC design and comprises development and production (stope) ore. Development ore includes only the Indicated Resources that are intersected by the development headings.
- For the SLC Stopes only Indicated Resource was included in the stoping shapes for production levels 2175mRL to 1775mRL
- All unclassified material (zero grade) lying within the above SLC Stopes was included as planned dilution essential for the mineable SLC shape. Similarly a small portion of Inferred resource (and its grade) required to define the SLC Stoping shapes was included as planned dilution with modeled grade. The total quantity included amounts to 1.08% of the SLC Stoping tonnes.
- A minimal quantity of inferred resource lying within the ore development was also included as planned dilution with modeled grade. The total quantity included amounts to less than 0.24% of the ore development ounces. All Inferred resource & unclassified material lying at the extremes of the ore body was excluded from the mine design and SLC Stoping shapes.
- The reserve estimate is based upon a cutoff grade of 2.2g/t and a gold price of US$800/oz.
Paboase
- The Underground Ore Reserve is based on SLC design and comprises development and production (stope) ore.
- The development and SLC Stope design shapes are based on Indicated Resources.
- All Inferred Resource material to be mined within the above SLC Stopes was considered dilution at zero grade. All Inferred Resource & unclassified material lying at the extremes of the ore body was excluded from the mine design and SLC Stoping shapes.
- Where an appropriate level of confidence exists for low grade mineralization within planned waste and dilution, this has been included in the reserve. This mineralization makes up 3% of the Au content in the reserve.
- The reserve estimates are based upon a cut off grade of 1.7g/t, and a gold price of US$800/oz.
The independent Surface Mineral Reserve estimate reported was undertaken under the supervision of Bruce Gregory (Member of the Australasian Institute of Mining and Metallurgy), Principal Mining Engineer of AMC Consultants Pty Ltd with more than five years experience in Ore Reserve estimation. For the purpose of reporting under National Instrument 43-101 Bruce Gregory is regarded as a Qualified Person.
The independent Akwaaba Deeps Undergound Mineral Reserve estimate reported was undertaken by Tony Silveira (Member of the Australasian Institute of Mining and Metallurgy), Senior Mining Engineer of AMC Consultants Pty Ltd with more than five years experience in Ore Reserve estimation. For the purpose of reporting under National Instrument 43-101 Tony Silveira is regarded as a Qualified Person
The independent Underground Ore Reserve estimate reported herein was undertaken by Herbert Smith B.Sc., P.Eng. (Member of the Association of Professional Engineers and Geoscientists of B.C.) of AMC Mining Consultants (Canada) Ltd with more than five years experience in Ore Reserve estimation for the purpose of reporting under National Instrument 43-101 Mr Smith is regarded as a Qualified Person.
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