Mineral Resource and Ore Reserve – a summary

Mineral Resources and Ore Reserves underpin growth

Mineral Resources and Ore Reserves 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, 2004 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). Mineral Resources are inclusive of the Ore Reserve component unless otherwise stated.

Mineral Resources

When the 2009 Mineral Resource is restated to exclude the sale of Tau Lekoa (6.2Moz), the Mineral Resource is reduced from 226.7Moz to 220.5Moz. The total Mineral Resource remained steady, dropping slightly from 220.5Moz in 2009 to 220.0Moz in December 2010. A year-on-year increase of 5.8Moz occurred before depletion is taken into account and a decrease of 0.5Moz after depletion. It should be noted that changes in economic assumptions from 2009 to 2010 resulted in the Mineral Resource increasing by 3.5Moz whilst exploration and modelling resulted in an increase of 0.7Moz.

The remaining increase of 1.6Moz resulted from various other factors. Depletions from the Mineral Resource for 2009 totalled 6.3Moz.

Mineral Resources have been estimated using a gold price of $1,100/oz (2009: $1,025/oz).

Ore Reserves

When the 2009 Ore Reserve is restated to exclude Tau Lekoa (0.8Moz), the 2009 Ore Reserve is reduced from 71.4Moz to 70.6Moz. Using the restated figure, the AngloGold Ashanti Ore Reserve increased from 70.6Moz in 2009 to 71.2Moz in December 2010. A year-on-year increase of 6.2Moz occurred before depletion of 5.6Moz, resulting in an increase of 0.6Moz after depletion. It should be noted that changes in the economic assumptions from 2009 to 2010 resulted in the Ore Reserve increasing by 2.4Moz while exploration and modelling resulted in a further increase of 3.8Moz.

Ore Reserves were estimated using a conservative gold price of $850/oz (2009: $800/oz).

Mineral Resource Moz
Mineral Resource as at 31 December 2009  226.7
Sale of Tau Lekoa  (6.2)
Restated 2009 Mineral Resource  220.5
Reductions   
Great Noligwa    Due to economics and depletion  (2.4)
TauTona    Transfers to Mponeng to improve change of mining  (1.3)
Siguiri    Revision to modelling procedures and increased costs  (1.0)
Other    Total of non-significant changes  (3.6)
Additions   
Vaal River Surface
{
 An economic study demonstrated that these tailings can be economically reworked to recover uranium 3.0
West Wits Surface  1.3
Other    Total of non-significant changes  3.5
Mineral Resource as at 31 December 2010  220.0

Rounding of numbers may result in computational discrepancies

Mineral Resource reconciliation
2010 vs 2009 (Moz)

Mineral Resource reconciliation

Ore Reserve reconciliation
2010 vs 2009 (Moz)

Ore Reserve reconciliation

Ore Reserve Moz
Ore Reserve as at 31 December 2009  71.4 
Sale of Tau Lekoa  (0.8)
Restated 2009 Ore Reserve  70.6
Reductions 
Geita  Depletions and model changes  (0.9)
Obuasi  Depletions and refinements to Ore Reserve estimation  (0.7)
Siguiri  Remodelling in accordance with reconciliation and depletion  (0.7)
TauTona  Depletion and transfers to Mponeng, minor model changes  (0.7)
Other  Total of non-significant changes  (1.2)
Additions 
Cripple Creek & Victor  MLE2 project study incorporated  1.4
Mponeng  Successful conversion drilling and minor transfers from TauTona and Savuka  1.2
Sadiola  Additions from Deep Sulphide project  0.8
Other  Total of non-significant changes  1.3
Ore Reserve as at 31 December 2010  71.2

Rounding of numbers may result in computational discrepancies

By-products

Several by-products are recovered as a result of the processing of gold Ore Reserves. These include 21,591t of uranium oxide from the South African operations, 443,761t of sulphur from Brazil and 34.6Moz of silver from Argentina. Details of by-product Mineral Resources and Ore Reserves are given in the Mineral Resource and Ore Reserve Report 2010*.

External audit of Mineral Resource

During the course of the year and as part of the rolling audit programme, AngloGold Ashanti’s 2010 Mineral Resources at the following operations were submitted for external audit by the Australian-based company Quantitative Group (QG):

AngloGold Ashanti’s 2010 Ore Reserves at the following operations were submitted for external audit by a number of international consulting companies, namely:

The company has been informed that the audits identified no material shortcomings in the process by which AngloGold Ashanti's Mineral Resources and Ore Reserves were evaluated. It is the company's intention to continue this process so that each of its operations will be audited, on average, every three years.

Competent persons

The information in this report relating to exploration results, Mineral Resources and Ore Reserves is based on information compiled by the Competent Persons. These individuals are identified in the expanded Mineral Resource and Ore Reserve Report 2010*. 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.

During the past decade, the company has developed and implemented a rigorous system of internal and external reviews of Exploration Results, Mineral Resources or Ore Reserves. A documented chain of responsibility exists from the Competent Persons at the operations to the company's Mineral Resource and Ore Reserve Steering Committee. Accordingly, the Chairman of the Mineral Resource and Ore Reserve Steering Committee, VA Chamberlain, MSc (Mining Engineering), BSc (Hons) (Geology), MGSSA, MAusIMM, 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 Resources and Ore Reserves is provided in the Mineral Resource and Ore Reserve Report 2010 (PDF - 5.69MB), which is available on or about 26 March 2011 on the AngloGold Ashanti website (www.anglogoldashanti.com), from where it may be downloaded as a PDF file using Adobe Acrobat Reader. The report is also available in printed format on request from the AngloGold Ashanti offices at the addresses given on the contact details page.

Inclusive Mineral Resource - attributable

    Tonnes Grade Contained gold
As at 31 December 2010 Category million g/t Tonnes Moz
South Africa  Measured 26.51 15.30 405.52 13.04
  Indicated 753.04 2.76 2,075.87 66.74
  Inferred 40.82 13.81 563.55 18.12
  Total (1)  820.38 3.71 3,044.94 97.90
Democratic Republic of the Congo  Measured – – – –
  Indicated 59.67 3.64 217.41 6.99
  Inferred 30.54 3.27 99.94 3.21
  Total  90.21 3.52 317.35 10.20
Ghana  Measured 77.12 4.83 372.49 11.98
  Indicated 83.38 3.82 318.84 10.25
  Inferred 105.26 3.71 390.99 12.57
  Total  265.76 4.07 1,082.33 34.80 
Guinea  Measured 43.18 0.65 28.28 0.91
  Indicated 101.78 0.77 78.19 2.51
  Inferred 77.77 0.85 66.11 2.13
  Total  222.73 0.77 172.58 5.55 
Mali  Measured 15.52 1.36 21.17 0.68
  Indicated 54.86 1.79 98.07 3.15
  Inferred 19.87 1.66 32.98 1.06
  Total 90.24 1.69 152.22 4.89
Namibia Measured 23.30 0.86 20.09 0.65
  Indicated 72.57 1.28 92.78 2.98
  Inferred 23.33 1.13 26.41 0.85
  Total 119.20 1.17 139.28 4.48
Tanzania Measured – – – –
  Indicated 80.32 3.37 270.88 8.71
  Inferred 21.95 3.62 79.57 2.56
  Total 102.27 3.43 350.46 11.27
Australia Measured 34.88 1.74 60.55 1.95
  Indicated 35.49 2.85 101.12 3.25
  Inferred 19.84 2.90 57.63 1.85
  Total 90.21 2.43 219.30 7.05
Argentina Measured 11.12 1.50 16.63 0.53
  Indicated 20.86 3.82 79.69 2.56
  Inferred 10.20 3.19 32.55 1.05
  Total 42.18 3.06 128.87 4.14
Brazil Measured 11.18 6.39 71.43 2.30
  Indicated 15.60 6.10 95.14 3.06
  Inferred 30.80 6.81 209.73 6.74
  Total 57.57 6.54 376.31 12.10
Colombia Measured – – – –
  Indicated 15.78 0.93 14.75 0.47
  Inferred 414.06 0.98 406.06 13.06
  Total 429.85 0.98 420.81 13.53
United States Measured 283.04 0.78 221.76 7.13
  Indicated 216.53 0.73 157.18 5.05
  Inferred 79.61 0.75 59.66 1.92
  Total 579.18 0.76 438.60 14.10
Total Measured 525.84 2.32 1,217.92 39.16
  Indicated 1,509.88 2.38 3,599.94 115.74
  Inferred 874.07 2.32 2,025.18 65.11
  Total 2,909.79 2.35 6,843.04 220.01
  1. (1) The reduction in grade relative to the Measured and Inferred Mineral Resource is due to the inclusion of 505Mt at 0.28g/t of tailings and rock dump Mineral Resource.

Exclusive Mineral Resource – attributable

    Tonnes Grade Contained gold
As at 31 December 2010 Category million g/t Tonnes Moz
South Africa  Measured 15.29 17.73 271.14 8.72
  Indicated 563.41 1.65 927.58 29.82
  Inferred 19.64 18.69 367.04 11.80
  Total (1)  598.34 2.62 1,565.75 50.34
Democratic Republic of the Congo  Measured – – – –
  Indicated 26.23 2.93 76.72 2.47
  Inferred 30.54 3.27 99.94 3.21
  Total  56.77 3.11 176.66 5.68
Ghana  Measured 29.69 6.96 206.52 6.64
  Indicated 34.46 2.45 84.26 2.71
  Inferred 105.26 3.71 391.01 12.57
  Total  169.41 4.02 681.79 21.92
Guinea  Measured 4.46 0.80 3.59 0.12
  Indicated 34.07 0.77 26.22 0.84
  Inferred 77.77 0.85 66.11 2.13
  Total  116.30 0.82 95.91 3.08
Mali  Measured 4.69 0.75 3.50 0.11
  Indicated 18.27 1.69 30.79 0.99
  Inferred 19.09 1.70 32.37 1.04
  Total 42.05 1.59 66.66 2.14
Namibia Measured 9.03 0.58 5.24 0.17
  Indicated 42.83 1.11 47.50 1.53
  Inferred 23.33 1.13 26.41 0.85
  Total 75.20 1.05 79.15 2.54
Tanzania Measured – – – –
  Indicated 41.62 2.93 121.83 3.92
  Inferred 21.95 3.62 79.57 2.56
  Total 63.57 3.17 201.40 6.48
Australia Measured 10.83 0.93 10.10 0.32
  Indicated 12.10 2.92 35.29 1.13
  Inferred 19.84 2.90 57.63 1.85
  Total 42.77 2.41 103.02 3.31
Argentina Measured 1.36 3.61 4.91 0.16
  Indicated 16.70 2.20 36.72 1.18
  Inferred 9.95 2.97 29.56 0.95
  Total 28.01 2.54 71.18 2.29
Brazil Measured 6.37 6.15 39.19 1.26
  Indicated 8.35 6.10 50.93 1.64
  Inferred 28.08 6.78 190.31 6.12
  Total 42.81 6.55 280.44 9.02
Colombia Measured – – – –
  Indicated 15.78 0.93 14.75 0.47
  Inferred 414.06 0.98 406.06 13.06
  Total 429.85 0.98 420.81 13.53
United States Measured 135.85 0.75 102.38 3.29
  Indicated 137.77 0.71 98.42 3.16
  Inferred 69.52 0.77 53.85 1.73
  Total 343.14 0.74 254.66 8.19
Total Measured 217.57 2.97 646.57 20.79
  Indicated 951.59 1.63 1,551.01 49.87
  Inferred 839.05 2.15 1,799.86 57.87
  Total 2,008.21 1.99 3,997.44 128.52
  1. (1) The reduction in grade relative to the Measured and Inferred Mineral Resource is due to the inclusion of 505Mt at 0.28g/t of tailings and rock dump Mineral Resource.

Ore Reserves by country – attributable

    Tonnes Grade Contained gold
As at 31 December 2010 Category million g/t Tonnes Moz
South Africa  Proved 12.03 8.24 99.07 3.19
  Probable 191.99 4.41 845.74 27.19
  Total 204.02 4.63 944.81 30.38
Democratic Republic of the Congo  Proved – – – –
  Probable 33.44 4.21 140.69 4.52
  Total 33.44 4.21 140.69 4.52
Ghana  Proved 44.01 3.13 137.85 4.43
  Probable 49.30 4.41 217.28 6.99
  Total 93.31 3.81 355.13 11.42
Guinea  Proved 39.05 0.62 24.38 0.78
  Probable 67.44 0.74 49.71 1.60
  Total 106.49 0.70 74.08 2.38
Mali  Proved 4.96 2.23 11.03 0.35
  Probable 39.18 1.78 69.82 2.24
  Total 44.14 1.83 80.86 2.60
Namibia Proved 14.27 1.02 14.49 0.47
  Probable 29.74 1.45 42.99 1.38
  Total 44.01 1.31 57.48 1.85
Tanzania Proved – – – –
  Probable 40.92 3.20 131.06 4.21
  Total 40.92 3.20 131.06 4.21
Australia Proved 24.05 2.10 50.45 1.62
  Probable 23.39 2.81 65.83 2.12
  Total 47.44 2.45 116.28 3.74
Argentina Proved 9.54 1.22 11.63 0.37
  Probable 8.57 5.32 45.62 1.47
  Total 18.10 3.16 57.25 1.84
Brazil Proved 6.91 5.80 40.06 1.29
  Probable 7.40 5.26 38.88 1.25
  Total 14.30 5.52 78.94 2.54
United States Proved 147.19 0.81 119.37 3.84
  Probable 78.76 0.75 58.76 1.89
  Total 225.95 0.79 178.13 5.73
Total Proved 302.00 1.68 508.32 16.34
  Probable 570.12 2.99 1,706.39 54.86
  Total 872.12 2.54 2,214.71 71.20

(2) The reduction in grade relative to the Proved Ore Reserve is due to the inclusion of 111Mt at 0.49g/t of tailings and rock dump Ore Reserve.

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