Broken Hill - Southern Operations
Resource and reserve estimates for the Southern Operations at Broken Hill are based on assays from diamond drilling and geological interpretation of drilling and geological mapping of underground development. This information is interpreted by mine geologists and used to develop a three-dimensional model of the geology, the distribution of mineralisation and mine openings. The current measured, indicated and inferred resource is 20.2 Mt at 9.0% zinc, 5.0% lead and 52 g/t silver, reported at an in-situ cut-off grade of 7.0% zinc and lead. Identified resources in areas considered inaccessible or unlikely to be accessed by future development have been excluded from the reported resource. These resources are retained in the geological model to enable their potential to be assessed should future mine development make their recovery possible. Modest potential exists for additional lead lode resources to be identified in the northern part of the mine.

The current proved and probable reserve is 16.6 Mt at 7.4% zinc, 3.9% lead and 41 g/t silver. The reserve estimate is based on the measured and indicated resource by intersecting actual three dimensional stope design shapes with the resource model and applying an external dilution factor based on the characteristics of each lode and stope type.

Compiled by C. Lutherborrow – Manager Geology and D.R. Edwards – Superintendent Mining Projects, Pasminco Broken Hill Mine.


Broken Hill – Potosi
Production from the Potosi open cut ceased in January 2000. Since 31 March 1999, 0.15 Mt at 6.5% zinc, 3.0% lead and 23 g/t silver was mined, fully depleting the previously reported ore reserve. Residual mineralisation extending to the north from beneath the Potosi open pit is currently considered uneconomic. A geological model has been prepared that represents currently known mineralisation between the Potosi open pit and the Barrier Main Lode three kilometres to the north to facilitate further assessment of its potential for surface or underground mining.

Compiled by C. Lutherborrow – Manager Geology and D.R. Edwards – Superintendent Mining Projects, Pasminco Broken Hill Mine.


Broken Hill – North No. 1 Underground
A detailed study of mineralisation between the North No 1 open pit resulted in 0.4Mt at 8.6% zinc, 8.3% lead and 149g/t silver being added to resources, using the same cut-off grade criteria used by the Southern Operations. The resource estimate is based on an exhaustive compilation of historic drilling and sampling data, additional RC drilling and modelling of both mineralisation and previously mined areas. Ore will be extracted by an underground decline from the existing open pit. The current reserve, inclusive of expected dilution and with recovery factors applied, is 0.18Mt at 7.4% zinc, 6.0% lead and 149g/t silver. Development will commence on receipt of approval by government agencies.

Compiled by C. Lutherborrow – Manager Geology and D.R. Edwards – Superintendent Mining Projects, Pasminco Broken Hill Mine.


Rosebery
The mineral resource at Rosebery has been estimated using assays from diamond drilling and geological mapping, interpreted by mine geologists to develop a three dimensional model of the orebody and remnant pillars. The current measured, indicated and inferred resource for the Rosebery mine is 9.5Mt at 14.8% zinc, 5.1% lead, 0.42% copper, 161g/t silver and 2.4g/t gold. A resource of 0.7Mt at 4.4% zinc, 2.1% lead, 0.2% copper, 139g/t silver and 2.8g/t gold is estimated for the South Hercules, Browns Tunnel and Southern Trenches prospects in the Rosebery mine area. Resources are reported using cut-off criteria based on the expected recovered metal value of contained zinc, lead, copper, silver and gold ($85 for underground resources and $65 for resources potentially amenable to surface mining). A minimum width requirement of 3 metres is also applied and resources must be considered currently or potentially accessible. Proved and Probable Reserves as at 31 March 2000 were 2.4Mt at 10.6% zinc, 3.9% lead, 0.52% copper, 120g/t silver and 2.5g/t gold. All reserves are within the Rosebery mine.

Reduced exploration during 1999 resulted in resources depleted by mining not being replaced. Revised geological interpretations of specific areas of the mine and the evaluation of resources potentially amenable to open cut mining also contributed to a reduction in resources since the last annual statement. Ventilation constraints in the Northern Exploration Decline slowed development and restricted infill drilling to convert identified resources to reserves. Decreases were partially offset by improved access to remnant pillars in the upper part of the mine. Exploration recommenced in March 2000. The focus will be on defining additional resources in known lenses in the northern part of the mine, and locating potential repetitions of mineralised lenses along strike to the south.

Compiled by P. Edwards – Geology Superintendent and R. McLean – Manager Mine Technical Services, Pasminco Rosebery Mine.


Elura
The Elura mine resource is based on assays from diamond drill holes and underground mapping, used to develop a detailed three-dimensional geological model of the orebody. The current measured and indicated resource of 19.2Mt at 8.6% zinc, 5.3% lead and 65g/t silver using a 10% zinc and lead cut-off. The resource estimate is based on the reinterpretation of deposit geology, controls on mineralisation continuity and distribution, and the characteristics of different ore types undertaken by mine geologists during the past year. The revised resource model forms the basis of a life of mine study, to be completed in August 2000.

The ore reserve at 31 March 2000 was 12.1Mt at 8.2% zinc, 4.9% lead and 58g/t silver, inclusive of dilution and recovery factors. All reserves are classified as proved following a full redesign of the stoping layout below 6 level completed during the past year.

Compiled by P. Leevers – Mine Geology Superintendent, R.W. Symes – Manager Technical Services NSW Mines and P. Fairfield – Manager Mining, Pasminco Elura Mine.

Century
Ore production from the Century open cut mine commenced during September 1999. The current measured, indicated and inferred resource stands at 102.4Mt at 12.2% zinc, 1.7% lead and 45g/t silver above a cut-off grade of 3.5% zinc, based on assays from diamond drill holes, used to develop a geological model of the deposit. The current proved and probable reserve is 96.9Mt at 11.6% zinc, 1.6% lead and 43g/t silver, inclusive of allowances for ore loss and dilution.

Additional drilling and detailed geological mapping has revealed greater than expected levels of faulting and folding affecting the distribution of mineralisation. Detailed geological mapping and reinterpretation of drilling data has established greater than expected resource continuity in the upper zone of the orebody. Appropriate systems are being implemented to ensure planned production levels will be maintained. Revision of the resource and reserve models currently in progress, focussing on the upper part of the orebody, will contribute to improved understanding of mineralisation distribution and opportunities for additional resource recovery. A system for reconciliation of mine production and concentrator receipts has been developed to ensure performance targets are met as the mine moves towards full production.

Compiled by I.J. Kelso – Senior Mine Operations Geologist and S. Bennett – Senior Mining Engineer, Pasminco Century Mine.

Dugald River
Re-evaluation of the Dugald River resource resulted in extensive revision of the geological model to improve the definition of distinct ore types and controls on mineralisation distribution. Grade estimation procedures used to develop the model benefited from an improved appreciation of mineralisation continuity. The current indicated and inferred resource estimate is 58.7Mt at 11.0% zinc, 1.8% lead and 34g/t silver using a cut-off of 7% zinc and lead cut-off, or 49.9Mt at 11.5% zinc, 1.9% lead and 37g/t silver at a 10% zinc and lead cut-off. Further drilling to obtain additional samples for metallurgical studies, test aspects of the revised geological model and improve the current understanding of major structures controlling mineralisation distribution and continuity is planned to commence in May 2000.

Compiled by C. Lutherborrow – Manager Geology, Pasminco Broken Hill Mine.

Gordonsville and Clinch Valley - Tennessee
Gordonsville and Clinch Valley are underground mines based on strata bound, carbonate hosted zinc resources. Several effectively flat lying deposits are mined at Gordonsville. The Clinch Valley deposit occurs in an area affected by regional thrust faulting in a moderately dipping sequence. Resources and reserve estimates are based on assays provided by surface and underground drilling. Classification of resources based on the density of drilling and whether mineralisation can be accessed from existing workings. Reported resources do not include reserves.

Reserves are estimated by applying a minimum mining height of 11 feet (approx. 3.4 metres) to resource blocks that may be developed from existing mine workings. Intersection thicknesses are converted to true thicknesses at Clinch Valley to compensate for the dip of the ore horizon. Blocks with diluted grades less than 2% zinc are excluded from reserves. Diluted block grades exceeding 4.5% zinc are cut to this value. No provision is made for pillars. Reserves at the Gordonsville and Clinch Valley Mines as of 31 March 2000 were 20.1Mt at 3.3% zinc and 2.9Mt at 3.3% zinc respectively.

US public resource and reserve reporting requirements currently differ from those applying in Australia. Work is in hand to ensure future resource and reserve reports will comply with JORC* standards.

Compiled by A. Wallace Mitchell – Geological Consultant.

Ernest Henry
Pasminco has a 49% interest in the Ernest Henry Mine in Queensland (MIM Ltd 51%).

Copper and gold mineralisation forming the Ernest Henry deposit occurs in a breccia comprising altered and replaced intermediate volcanics that is currently being mined by open-cut methods. Mineralogically distinct supergene and primary ore types are recognised within the deposit. The resource and reserve estimates are based on assays from diamond drilling used in conjunction with a geological interpretation of the different ore types forming the deposit to prepare a three dimensional block model. A life of mine study was completed during 1999-2000. The mine also moved from a contractor to owner operated mining operation during the past year.

The estimated supergene and primary resource at 31 March 2000 was 148Mt at 1.1% copper and 0.53g/t gold, using cut-off grades of 0.5% and 0.4% copper for supergene and primary mineralisation respectively. These resources incorporate an ore reserve comprising 106Mt at 1.1% copper and 0.55g/t gold as defined in the latest life of mine open pit study. A review of the resources that do not form part of the life of mine plan is to be undertaken prior to the publication of the next reserve/resource statement.

Compiled by D.J. Ayliffe – Senior Mine Geologist and Richard Crookes – Mining Manager, Ernest Henry Mine.



* Australasian code for reporting of mineral resources and ore reserves (The JORC Code), prepared by the Joint Ore Reserve Committee of the Australasian Institute of Mining and Metallurgy, Australian Institute of Geoscientists and Minerals Council of Australia (JORC), effective September 1999.

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The financial information presented on this web site represents extracts from the audited financial report of Pasminco Limited for the financial year ended 30 June 2000 issued on 22 September 2000. These extracts cannot be expected to provide as full an understanding of the financial performance, financial position and financing and investing activities of the entity as a reading of the complete financial report.

The complete financial report, and the audit report thereon, can be obtained, free of charge, on request to the entity
annualreport@Pasminco.com.au

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