Mineral Resources and Ore Reserves
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Total in situ Mineral Resources at year end for the Group, net of mining depletion, are estimated at 62 million ounces of gold and 5 million tonnes of copper, which is an increase in the resource of 8.4 million ounces of gold and an increase of 1.2 million tonnes of copper compared with June 2003.
There was a major increase in Mineral Resources at Cadia East Underground with the addition of 8.4 million ounces of gold and 1.2 million tonnes of copper in situ.
Ore Reserves are estimated at 28 million ounces of gold and 1.4 million tonnes of copper in situ.
Mineral Resources and Ore Reserves conform to the Australasian Code for Reporting of Mineral Resources and Ore Reserves (The Joint Ore Reserves Committee Code). Ore Reserves are a sub-set of Mineral Resources. External and internal audits are conducted on completed estimates. All costs and prices are in Australian dollars unless stated otherwise. Relevant information on the methods and parameters used to estimate Mineral Resources and Ore Reserves are presented in the Newcrest Supplementary Information Booklet located in the Annual Report section on the Company’s website at www.newcrest.com.au.
Cadia Hill
The Cadia Hill Mineral Resource and Ore Reserve were depleted by 14.5 million
tonnes during the period. This was partially offset by a 6.1 million tonne
increase due to copper recovery improvements. A reduction of 12.3 million
tonnes to the Cadia Hill Ore Reserve was also made by removing marginal
material that will not be processed. Reconciliation of production results
continue to show very good correlation with the Mineral Resource and Ore
Reserve models.
Cadia Extended
The open pit mining at Cadia Extended was completed and the associated Ore
Reserve was depleted during the year. The Mineral Resource has been depleted
by mining and the remaining Mineral Resource is being evaluated.
Cadia Stockpiles
Open pit stockpiles increased by 4.5 million tonnes during the period. This
change is net of mining reclaim, new material added and metallurgical adjustments.
Ridgeway
Continued drilling of Ridgeway Deeps has resulted in an addition to the
Mineral Resource. This was offset by mining depletion resulting in a net
reduction of 1.5 million tonnes to the Mineral Resource during the period.
At Ridgeway Underground there was a net increase in Ore Reserves after mining depletion of 0.7 million ounces of gold and 0.09 million tonnes of copper in situ. An increase in reserves of 1.23 million ounces and 0.15 million tonnes of copper defined from the Ridgeway Deeps zone and other extensions was offset by Ridgeway mining depletions to arrive at the net outcome.
Cadia East Open Pit
The Mineral Resource for the open cut component to the Cadia East deposit
remains unchanged. Resource definition drilling is planned to upgrade this
resource in 2004/05.
Cadia East Underground
The underground component of the Cadia East Mineral Resource (formerly known
as Cadia Far East) increased by 400 million tonnes during the period. The resource is predicated on bulk
underground extraction methods and has been reported within conceptual mining outlines.
An updated Mineral Resource estimate was published in a market release in February 2004. Subsequent drilling has significantly expanded the deposit further to the west resulting in increased tonnes in the Inferred category. Mineralisation remains open at depth and to the west.
Telfer
The Telfer Mineral Resource and Ore Reserve Statements remain unchanged
since June 2003.
Open Pit
Open Pit mining commenced late 2003 and this material was stockpiled, according
to ore type, in preparation for milling which will commence in the December
quarter 2004. Total grade control production reconciliation to the reserve
remains in line with the feasibility estimates.
Telfer Deeps
Drilling and bulk sampling exploration activity continued in the western
flank of the feasibility sub-level cave operation. Bulk sampling results
within the sub-level cave are in line with feasibility estimates.
The Telfer Open Pit ore reserve is constrained within pit designs based on optimisation shells generated using the profit algorithm approach.
The Telfer Deeps ore reserve is based on a sub-level cave mining method designed using a series of break even boundaries for each production level.
Studies continue to evaluate mining strategies for the potential extensions to the Telfer Deeps mineralisation.
Boddington
The Boddington Expansion Mineral Resource and Ore Reserve estimates and
the Basement Mineral Resource estimate are the same as those reported last
year. A revision of the resource estimate is in progress and will incorporate
revisions of cost assumptions arising from the Feasibility Study Update
currently in progress.
Toguraci
Net of mining depletion the Toguraci Ore Reserve increased by approximately
5 percent during the year to 0.22 million ounces contained gold. Resource
additions at Kayu Manis replaced mining depletion. The Toguraci Mineral
Resource therefore remained unchanged at 0.30 million ounces.
Material changes during the period included the addition of a new resource at Kayu Manis, subsequent redesign of the pit and depletion due to the commencement of mining.
The Kayu Manis vein is located immediately to the south of Damar and represents a natural extension of the pit in that direction. The net contribution of Kayu Manis to the Mineral Resource was 0.05 million ounces and the Toguraci pit was re-optimised to include Kayu Manis.
Mining focussed on the Damar and Midas veins where a total of 0.06 million ounces was depleted. Strong grade over-performance at Damar and contributions from cross-cutting mineralised structures resulted in a net production of 0.07 million ounces. Significant open pit upside remains with the likely inclusion of the BoD veins located to the west of Damar.
Gosowong Extended (Kencana)
The first Mineral Resource estimate for the Kencana discovery was released
in February this year. The Gosowong Extended Project team has commenced
to progress studies into the feasibility of developing the Kencana Shoot
as a new high grade ore source at Gosowong.
Cracow
The Royal and Crown Mineral Resources remain unchanged.
Underground drilling commenced which will provide data on geology and grade continuity for the location of the initial ore drives and for stoping block outlines in the upper levels. Remodelling of the upper part of the Royal will then be completed and this will permit an update of the Royal Resource in 2004/05.
2004 Mineral Resources
| Measured Resource | Indicated Resource | Inferred Resource | Gold In situ | Copper In situ | Competent Person | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gold and Copper Resources |
Dry Tonnes (million) | Gold Grade (g/t Au) |
Copper Grade (% Cu) |
Dry Tonnes (million) | Gold Grade (g/t Au) |
Copper Grade (% Cu) |
Dry Tonnes (million) | Gold Grade (g/t Au) |
Copper Grade (% Cu) |
(million ounces) | (kilo-tionnes) | |
| Cadia Hill | 210 | 0.71 | 0.16 | 40 | 0.59 | 0.16 | 5.6 | 400 | 1 | |||
| Cadia Extended | 0.1 | 0.36 | 0.20 | 36 | 0.40 | 0.22 | 4.0 | 0.39 | 0.17 | 0.51 | 87 | 1 |
| Cadia Stockpiles | 15 | 0.41 | 0.16 | 0.20 | 24 | 1 | ||||||
| Ridgeway | 42 | 2.0 | 0.66 | 16 | 2.1 | 0.67 | 19 | 1.4 | 0.54 | 4.5 | 480 | 1 |
| Ridgeway Stockpiles | 0.076 | 2.9 | 0.87 | 0.007 | 0.66 | 1 | ||||||
| Cadia East Open Pit | 300 | 0.46 | 0.37 | 4.3 | 1100 | 1 | ||||||
| Cadia East Underground | 210 | 1.0 | 0.38 | 320 | 0.69 | 0.30 | 14 | 1800 | 1 | |||
| Telfer | ||||||||||||
| Open Pit | 170 | 1.3 | 0.17 | 200 | 1.7 | 0.13 | 94 | 1.1 | 0.12 | 21 | 670 | 2 |
| Underground | 46 | 2.8 | 0.52 | 11 | 2.0 | 0.41 | 4.8 | 290 | 2 | |||
| Satellites | 0.72 | 4.2 | 0.06 | 1.7 | 2.6 | 0.08 | 0.24 | 1.9 | 2 | |||
| Stockpiles | 3.1 | 0.83 | 0.14 | 0.08 | 4.4 | 2 | ||||||
| Subtotal | 170 | 1.3 | 0.17 | 250 | 1.9 | 0.20 | 110 | 1.2 | 0.15 | 26 | 960 | |
| Boddington | ||||||||||||
| Basement | 0.081 | 1.8 | 0.12 | 2.1 | 0.022 | 9.0 | 0.02 | 3 | ||||
| Boddington Expansion | 29 | 0.93 | 0.11 | 82 | 0.83 | 0.12 | 51 | 0.8 | 0.091 | 4.4 | 180 | 4 |
| Subtotal | 29 | 0.93 | 0.11 | 82 | 0.83 | 0.12 | 51 | 0.8 | 0.091 | 4.4 | 180 | |
| Toguraci Open Pit | 0.23 | 34 | 0.10 | 17 | 0.30 | 5 | ||||||
| Gosowong Extended | 0.25 | 69 | 0.44 | 26 | 0.92 | 5 | ||||||
| Toguraci Stockpiles | 0.014 | 27 | 0.013 | 5 | ||||||||
| Gosoowong Stockpiles | 0.071 | 2.7 | 0.0063 | 5 | ||||||||
| Cracow | 1.7 | 10 | 0.55 | 6 | ||||||||
| Total Gold and Copper Resources | 62 | 5,000 | ||||||||||
1. C. F. Moorhead, 2. G. R. Howard, 3. K. P. Gleeson, 4. S. Williams, 5. G. N. Petersen, 6. J. F. Leckie/P. Creenaune
Rounding, conforming to the JORC Code, may cause some computational discrepancies and total gold has been rounded to two significant figures. The gold and copper grade totals in the resources are weighted averages.
Information in this report which relates to Mineral Resources is based on and accurately reflects reports prepared by the Competent Person named beside the information. All these persons are full-time employees of Newcrest Mining Limited or the relevant subsidiary, except K. P. Gleeson, who is a full-time employee of Boddington Gold Mine Management Company Pty Ltd and S. Williams, who is a full-time employee of Newmont Australia Limited, and consent to the inclusion of material in the form and context in which it appears. Mr J. F. Leckie, Chief Geologist Mining and Development, Newcrest Mining Limited, is the Competent Person who has compiled this resource report. All the Competent Persons are Members or Fellows of The Australasian Institute of Mining and Metallurgy and/or the Australian Institute of Geoscientists and have the relevant experience in relation to the mineralisation being reported on by them to qualify as Competent Persons as defined in the Australasian Code for Reporting of Mineral Resources and Ore Reserves.
Newcrest has retained Mr Peter Stoker of Hackchester Pty Ltd to act as an external auditor for the Newcrest Mineral Resources where Newcrest is the operator. Mr Stoker has progressively audited these Mineral Resources and has stated that he is not aware of any issues which materially affect the reported Mineral Resources. Mr Stoker is a geologist with 35 years’ experience in mine geology, Mineral Resource and Ore Reserve estimation, feasibility studies, project evaluation and mineral exploration.
2004 Ore Reserves
| Proved Reserve | Probable Reserve | Gold In situ | Copper In situ | Competent Person | |||||
|---|---|---|---|---|---|---|---|---|---|
| Gold and Copper Resources |
Dry Tonnes (million) | Gold Grade (g/t Au) |
Copper Grade (% Cu) |
Dry Tonnes (million) | Gold Grade (g/t Au) |
Copper Grade (% Cu) |
(million ounces) | (kilo-tionnes) | |
| Cadia Hill | |||||||||
| Cadia Hills | 145 | 0.81 | 0.18 | 3.2 | 0.41 | 0.19 | 3.8 | 260 | 1 |
| Stockpiles | 15 | 0.41 | 0.16 | 0.2 | 24 | 1 | |||
| Subtotal | 160 | 0.77 | 0.17 | 3.2 | 0.41 | 0.19 | 4.0 | 284 | |
| Ridgeway | |||||||||
| Underground | 31 | 2.0 | 0.66 | 29 | 1.7 | 0.56 | 3.5 | 360 | 2 |
| Stockpiles | 0.08 | 2.9 | 0.87 | 0.01 | 0.7 | 2 | |||
| Subtotal | 31 | 2.0 | 0.66 | 29 | 1.7 | 0.56 | 3.5 | 360 | |
| Telfer* | |||||||||
| Main Dome | 130 | 1.3 | 0.21 | 120 | 1.5 | 0.15 | 12 | 430 | 3 |
| West Dome | 37 | 1.0 | 0.08 | 49 | 1.1 | 0.08 | 3.0 | 55 | 3 |
| Telfer Deeps | 39 | 2.7 | 0.50 | 3.4 | 200 | 4 | |||
| Subtotal | 167 | 1.3 | 0.18 | 210 | 1.6 | 0.20 | 18 | 685 | |
| Boddington | |||||||||
| Expansion | 28 | 0.94 | 0.12 | 59 | 0.84 | 0.13 | 2.4 | 110 | 5 |
| Subtotal | 28 | 0.94 | 0.12 | 59 | 0.84 | 0.13 | 2.4 | 110 | |
| Gosowong | |||||||||
| Toguraci Pit* | 0.18 | 37 | 0.22 | 6 | |||||
| Toguraci Stockpiles | 0.01 | 27.0 | 0.01 | 6 | |||||
| Gosowong Stockpiles | 0.07 | 2.7 | 0.01 | 6 | |||||
| Subtotal | 0.08 | 6.0 | 0.18 | 37 | 0.24 | ||||
| Total Gold and Copper Reserves | 28 | 1,439 | |||||||
1. C. F. Moorhead, 2. G. Dunstan, 3. M. Staples, 4. A. Pratt, 5. S. Williams, 6. G. N. Petersen
Rounding, conforming to the JORC Code, may cause some computational discrepancies and total gold has been rounded to two significant figures.
Information in this report which relates to Ore Reserves is based on and accurately reflects reports prepared by the Competent Person indicated beside the information. All these persons are full-time employees of Newcrest Mining Limited or the relevant subsidiary, except S. Williams, who is an employee of Newmont Australia Limited and M. Staples, who was an employee of Australian Mining Consultants Pty Ltd contracted to Newcrest Mining Limited, who has consented to the inclusion of material in the form and context in which it appears. Mr A. S. Logan, Manager Business Improvement, Newcrest Mining Limited, is the Competent Person who has compiled this reserve statement. All the Competent Persons are members of The Australasian Institute of Mining and Metallurgy and/or the Australian Institute of Geoscientists and have the relevant experience in relation to the mineralisation being reported on by them to qualify as Competent Persons as defined in the Australasian Code for Reporting of Mineral Resources and Ore Reserves.
AMC Consultants Pty Ltd was engaged to conduct audits on the process used for Ore Reserve estimation for Cadia Hill, Ridgeway and Gosowong. AMC Consultants is not aware of any issues with the process used which may materially affect these reported Ore Reserves. Reserves quoted for Telfer and Boddington are unchanged from the 2003 report.
*A small proportion (approximately 5 percent) of the Telfer and Toguraci open pit reserves fall within pit increments which are dependent on the inclusion of Inferred Resources to meet the economic criteria for production. Newcrest has every expectation that additional drilling that is planned will upgrade these Inferred Resources.