West Africa region - Mineral Resources and Mineral Reserves

Mineral Resources

The Mineral Resources declared 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:

  • Cut-off grades are calculated for the individual deposits
  • The application of realistic modifying factors to ensure that there is a reasonable prospect of eventual economic extraction
  • Use of an appropriate in situ economic cut-off grade with tonnages and grades based on the relevant resource block models, and include estimates of any material below the cut-off grade required to be mined to extract the complete economic portion of the Mineral Resource
  • Open pit Mineral Resources comprise the material above the nominated cut-off within a diluted optimised pit shell and constrained to an optimised 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 realistic modifying factors and the use of appropriate cut-off grades, geotechnical criteria, mining fleet productivities and other techno-economic investigations.

West Africa region summary of the Mineral Resource and Mineral Reserve statement1

  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)		  
Damang 86.2 2.21 6.12 5.98     Damang 31.9 1.68 1.73 1.67  
Tarkwa – open pits 172.5 1.37 7.58 8.12     Tarkwa – open pits 122.5 1.23 4.83 5.10  
Tarkwa – surface stocks 72.2 0.46 1.07 0.98     Tarkwa – surface stocks 72.2 0.46 1.07 0.98  
Total West Africa 331.0 1.39 14.78 15.07     Total West Africa 226.6 1.05 7.63 7.76  

Mineral Resources are inclusive of Mineral Reserves. All tonnes (t) relate to metric units. Rounding-off of figures may result in minor computational discrepancies, where this happens it is not deemed significant. In West Africa (Damang and Tarkwa) the Mineral Resources and Mineral Reserves were determined using a gold price of US$1,400/oz and US$1,200/oz respectively

1Managed, unless otherwise stated