Estimacion de reserva

ESTIMATION OF MINERAL RESOURCES And MINERAL RESERVES BEST PRACTICE GUIDELINES

Committee Members Paul Bankes - Teck Cominco Limited, Vancouver. Ralph Bullis - Echo Bay Mines Ltd., Edmonton. Neil Gow - Roscoe Postle Associates Inc., Toronto. Bernie Haystead - CIBC World Markets, Toronto. Alfred Hills - Placer Dome Inc., Vancouver. Stephen Juras - MRDI, Vancouver. Marc Legault - Agnico-EagleMines Limited, Toronto, Philip Olson - Claude Resources Inc., Saskatoon. Albert Samis - Teck Cominco Limited, Vancouver. Paul Severin - Falconbridge Limited, Toronto. Val Spring - Watts, Griffis and McOuat, Toronto. Advisors Francis Manns - Toronto Stock Exchange, Toronto. Deborah McCombe - Ontario Securities Commission, Toronto. Alastair Sinclair - University of British Columbia, Vancouver.

May 30, 2003 - Adopted by CIM Council on November 23, 2003.

Table of Contents Executive Summary............................................................................................................ 1 General Guidelines .............................................................................................................. 7 Preamble.......................................................................................................................... 7 1. Qualified Person.......................................................................................................... 7 2. Definitions ................................................................................................................... 8 3. The ResourceDatabase............................................................................................... 9 4. Geological Interpretation & Modeling...................................................................... 13 5. Mineral Resource Estimation.................................................................................... 16 6. Quantifying Elements to convert a Mineral Resource to a Mineral Reserve ........... 19 7. Mineral ReserveEstimation...................................................................................... 22 8. Reporting................................................................................................................... 25 9. Reconciliation of Mineral Reserves .......................................................................... 30 Selected References...................................................................................................... 35 Guidelines Specific to Particular Commodities ................................................................ 36 Potash............................................................................................................................ 36 Industrial Minerals........................................................................................................ 37 Coal ............................................................................................................................... 44 Uranium ........................................................................................................................ 47

Executive Summary The following is a summary, in table format, of the main elementsof the Estimation Best Practice Committee's report “Estimation of Mineral Resource and Mineral Reserve Best Practice Guidelines”. While the summary table is provided for convenience, the Committee recommends that the report be read in its entirety and the table summary not be used as a stand alone document. These guidelines are not intended to be either prescriptive or exhaustive. They do notpreclude innovation.

Preamble: These guidelines have been prepared by the Canadian Institute of Mining and Metallurgy and Petroleum (CIM) led Estimation Best Practices Committee. They are intended to assist the Qualified Person(s) (QP) in the planning, supervision, preparation and reporting of Mineral Resource and Mineral Reserve (MRMR) estimates. All MRMR estimation work from which public...