Performance review

Mineral Resource and Ore Reserve overview

The AngloGold Ashanti Mineral Resource and Ore Reserve are reported in accordance with the minimum standards described by the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code, 2012 Edition), and also conform to the standards set out in the South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (The SAMREC Code, 2007 edition and amended July 2009).

The Mineral Resource is inclusive of the Ore Reserve component unless otherwise stated. In complying with revisions to the JORC Code, changes to AngloGold Ashanti’s Mineral Resource and Ore Reserve have been reviewed and it was concluded that none of the changes are material to the overall valuation of the company. AngloGold Ashanti has therefore once again resolved not to provide the detailed reporting as defined in Table 1 of the code. The company will however continue to provide the high level of detail it has in previous years in order to comply with the transparency requirements of the code.

AngloGold Ashanti strives to actively create value by growing its major asset, the Mineral Resource and Ore Reserve. This drive is based on active, well-defined brownfields and greenfields exploration programmes, innovation in both geological modelling and mine planning, and continual optimisation of its asset portfolio.


The following local prices of gold were used as a basis for estimation in the December 2014 declaration:

Local prices of gold
 South AfricaAustraliaBrazilArgentina
2014 Ore Reserve1,100398,4521,2612,8018,979
2014 Mineral Resource1,600429,8031,5663,18412,319

The JORC and SAMREC Codes require the use of reasonable economic assumptions. These include long-range commodity price forecasts which are prepared in-house.


The total Mineral Resource decreased from 233.0Moz in December 2013 to 232.0Moz in December 2014. A gross annual increase of 8.7Moz occurred before depletion and disposals, while the net decrease after allowing for depletion and disposals was 1.0Moz. Changes in economic assumptions from December 2013 to December 2014 resulted in a 6.4Moz decrease in the Mineral Resource, while exploration and modelling resulted in an increase of 14.4Moz. Depletion from the Mineral Resource for the year totalled 5.9Moz and the reduction from the sale of Navachab, 3.8Moz. The Mineral Resource was estimated at a gold price of US$1,600/oz (2013: US$1,600/oz).

Mineral Resource
As at 31 December 2013 233.0
Disposal – Navachab (3.8)
Depletion (5.9)
QuebradonaNuevo Chaquiro Maiden Mineral Resource declaration5.5
La ColosaMineral Resource growth due to exploration success5.1
AGA MineraçãoExploration success at all three operations2.1
Sunrise DamRevisions to the modelling approach1.6
SiguiriHard rock exploration additions from three deposits1.5
OtherAdditions less than 0.5Moz1.5
MponengData driven revision to models and Mineral Resource clean up(3.4)
KopanangMineral Resource clean-up of uneconomic and inaccessible areas(1.8)
Moab KhotsongExploration-driven revisions to models(1.4)
(including Great Noligwa)  
GeitaIncreased costs resulting in reduced pit size(0.9)
OtherReductions less than 0.5Moz(1.1)
As at 31 December 2014Total232.0

Rounding of numbers may result in computational discrepancies.


The AngloGold Ashanti Ore Reserve reduced from 67.9Moz in December 2013 to 57.5Moz in December 2014. This gross annual decrease of 10.5Moz includes depletion of 4.9Moz and the sale of Navachab of 1.9Moz. The remaining reduction of 3.7Moz in the Ore Reserve resulted from changes to the economic assumptions between 2013 and 2014 which resulted in a reduction of 3.0Moz to the Ore Reserve, while exploration and modelling changes led to a further decrease of 0.7Moz. The Ore Reserve has been estimated using a gold price of US$1,100/oz (2013: US$1,100/oz).

Ore Reserve
As at 31 December 2013 67.9
Disposal – Navachab (1.9)
Depletion (4.9)
SiguiriInclusion of fresh rock from the Kami deposit0.6
Sunrise DamExploration success at Vogue0.4
OtherAdditions less than 0.3Moz1.0
ObuasiInitial results of feasibility study(2.6)
MponengRevisions to the CLR and VCR models due to new exploration and(1.3)
 development data 
Moab KhotsongNew surface exploration data led to revision of the project Zaaiplaats models(0.8)
(including Great Noligwa)  
CC&VIncreased costs and reduction in sub marginal ounces(0.4)
OtherReductions less than 0.3Moz(0.5)
As at 31 December 2014Total57.5

Rounding of numbers may result in computational discrepancies


Several by-products are recovered in the processing of the gold Ore Reserve. The AngloGold Ashanti Ore Reserve includes 55,600t of uranium oxide at the South African operations, 0.32Mt of sulphur in Brazil and 25.1Moz of silver in Argentina.

The maiden publication of the Nuevo Chaquiro Mineral Resource added 3.55Mt of copper, 76.5Moz of silver and 62,908t of molybdenum to the group’s total Mineral Resource.


AngloGold Ashanti has developed and implemented a rigorous system of internal and external reviews to provide assurance of its Mineral Resource and Ore Reserve estimates.

The information in this report relating to exploration results, Mineral Resources and Ore Reserves is based on information compiled by or under the supervision of the Competent Persons as defined in the JORC or SAMREC Codes. All Competent Persons are employed by AngloGold Ashanti, unless stated otherwise, and have sufficient experience relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaking. The Competent Persons consent to the inclusion of exploration results, Mineral Resource and Ore Reserve information in this report, in the form and context in which it appears. The legal tenure of each operation and project has been verified to the satisfaction of the accountable Competent Person.

During the past decade, the company has developed and implemented a rigorous system of internal and external reviews aimed at providing assurance in respect of Ore Reserve and Mineral Resource estimates. The Mineral Resource and Ore Reserve at the following operations were subject to an external review, in line with the policy that each operation or project will be reviewed by an independent third party on average once every three years:

  • Mponeng
  • Moab Khotsong
  • Iduapriem
  • Sunrise Dam
  • Cerro Vanguardia
  • Serra Grande
  • Obuasi

The external reviews were conducted by the following companies: The Mineral Corporation (Mponeng and Moab Khotsong), Coffey Mining (Iduapriem), Snowden (Sunrise Dam), Optiro (Cerro Vanguardia and Serra Grande), AMEC (Obuasi – Mineral Resource) and SRK (Obuasi – Mineral Resource and Ore Reserve). Certificates of sign-off have been received from all companies conducting the external reviews to state that the Mineral Resource and/or Ore Reserve at each operation complies with the JORC Code and the SAMREC Code.

Numerous internal Mineral Resource and Ore Reserve process reviews were completed by suitably qualified Competent Persons from within AngloGold Ashanti. A documented chain of responsibility exists from the Competent Persons at the operation to the company’s Mineral Resource and Ore Reserve Steering Committee. Accordingly, the Chairman of the AngloGold Ashanti Mineral Resource and Ore Reserve Steering Committee, VA Chamberlain, MSc (Mining Engineering), BSc (Hons) (Geology), MGSSA, FAusIMM, assumes responsibility for the Mineral Resource and Ore Reserve processes for AngloGold Ashanti and is satisfied that the Competent Persons have fulfilled their responsibilities.

A detailed breakdown of Mineral Resource and Ore Reserve and backup detail is provided in the Mineral Resource and Ore Reserve Report 2014.

Mineral Resource by region inclusive of Ore Reserve (attributable)
  TonnesGrade Contained gold
As at 31 December 2014Categorymilliong/tTonnesMoz
South AfricaMeasured147.192.35345.9111.12
  Inferred 47.34 10.31 487.87 15.69
Continental AfricaMeasured79.943.07245.067.88
  Inferred 277.85 2.40 667.86 21.47
  Inferred 23.35 2.73 63.84 2.05
  Inferred 1,076.04 0.74 799.23 25.70
AngloGold Ashanti totalMeasured543.411.77962.7430.95
  Inferred 1,424.57 1.42 2,018.80 64.91

Rounding of figures may result in computational discrepancies.

Mineral Resource by region exclusive of Ore Reserve (attributable)
  TonnesGrade Contained gold
As at 31 December 2014Categorymilliong/tTonnesMoz
South AfricaMeasured15.7515.17239.067.69
  Inferred 13.43 18.32 246.09 7.91
Continental AfricaMeasured36.804.89179.785.78
  Inferred 276.82 2.39 661.34 21.26
  Inferred 23.35 2.73 63.84 2.05
  Inferred 1,064.18 0.74 784.22 25.21
AngloGold Ashanti totalMeasured213.942.82602.9119.38
  Inferred 1,377.77 1.27 1,755.49 56.44
Ore Reserve by region (attributable)
  TonnesGrade Contained gold
As at 31 December 2014Categorymilliong/tTonnesMoz
South AfricaProved133.450.6485.202.74
  Probable 713.99 1.08 768.72 24.71
Continental AfricaProved44.951.5268.122.19
  Probable 203.84 2.55 520.67 16.74
  Probable 28.19 2.38 67.09 2.16
  Probable 72.87 1.50 109.03 3.51
AngloGold Ashanti totalProved331.300.97322.0310.35
  Probable 1,018.90 1.44 1,465.51 47.12

Rounding of figures may result in computational discrepancies.

Regional reviews Five-year operational statistics