Australia region - Mineral Resources and Mineral Reserves

Mineral Resources

The Mineral Resources declared within the Australia region are classified as Measured, Indicated or Inferred, as described in the SAMREC Code. Mineral Resource categories are assigned with consideration given to geological complexity, grade variance, drill hole intersection spacing and mining development. The following factors apply to the Mineral Resources reported:

  • All Mineral Resources are declared using a cut-off grade calculated for the individual deposit
  • Mineral Resources are further tested through the application of realistic modifying factors to ensure that there is a reasonable prospect of eventual economic extraction
  • Mineral Resources are quoted at an appropriate in situ economic cut-off grade with tonnages and grades based on the relevant resource block models. They also include estimates of any material below the cut-off grade required to be mined to extract the complete pay portion of the Mineral Resource
  • Open pit Mineral Resources (with the exception of Gruyere) comprise the material above the nominated cut-off grade within a diluted optimised pit shell and are constrained to an optimised minimum mining width shape
  • Underground Mineral Resources comprise the material above the nominated cut-off grade and are constrained to a practical mining shape and a minimum mining width
Mineral Reserves

The Mineral Reserve estimates are based on appropriately detailed and engineered LoM plans. All design and scheduling work is undertaken to a suitable level of detail by experienced engineers using appropriate mine planning software. The planning process incorporates relevant modifying factors and the use of cut-off grades and results from other techno-economic investigations. All prevailing geotechnical protocols and constraints are taken account of in the mine design and scheduling, including the provision of sufficient waste storage and tailing storage facilities to meet LoM requirements.

Australia region: Summary Mineral Resource and Mineral Reserve statement for operational mines1

   Mineral Resources        Mineral Reserves    
   December 2017  Dec 
2016
 
      December 2017  Dec 
2016
 
  
Measured,
Indicated
and Inferred 
Tonnes 
(Mt)
Grade 
(g/t)
Gold 
(Moz)
Gold 
(Moz)
   Proved and
Probable 
Tonnes 
(Mt)
Grade 
(g/t)
Gold 
(Moz)
Gold 
(Moz)
  
Agnew  11.5  5.25  1.946  2.142     Agnew  3.0  5.54  0.541  0.515    
Darlot        0.224     Darlot        0.056    
Granny Smith  38.6  5.70  7.075  6.520     Granny Smith  12.4  5.51  2.203  1.693    
St Ives  34.4  3.47  3.847  3.297     St Ives  19.4  2.51  1.568  1.740    
Gruyere  75.4  1.29  3.134  3.307     Gruyere  48.7  1.20  1.871  1.760    
Total  160.0  3.11  16.002  15.490     Total  83.5  2.30  6.183  5.764    
1 Managed, unless otherwise stated (Gruyere: only the Gold Fields attributable figures are reported)
Mineral Resources are inclusive of Mineral Reserves
All tonnes (t) relate to metric units and rounding-off of figures may result in minor computational discrepancies, where this happens, it is not deemed significant