March 24, 2018
  CIM Magazine - Standards Column
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CIM Standing Committee of Reserves Definitions
CIM Reserve Definitions Committee History
The CIM Definition Standards for Mineral Resources and Mineral Reserves, prepared by the CIM Standing Committee on Mineral Reserve and Mineral Resource Definitions, provides definitions and guidelines for the classification of Mineral Resource, Mineral Reserve and mining studies used in Canada. The Mineral Resource, Mineral Reserve, and Mining Study definitions are  incorporated, by  reference, into National Instrument 43-101  –  Standards  of  Disclosure  for Mineral Projects (NI 43-101).

The category of an estimate is based on confidence in the geological information available on the mineral deposit; the quality and quantity of data available on the deposit; the level of detail of the technical and economic information that has been generated about the deposit, and the interpretation of the data and information.

Special Committee on Reserve Definitions was formed

In 1991, CIM, through its Mineral Economics Society, formed a Special Committee on Reserve Definitions to prepare standard definitions of mineral resources and mineral reserves. The report of the Special Committee on standard mineral and resource definitions was presented to CIM Council in May 1994 and published in October 1994 in the CIM Bulletin.

In June 1994, CIM Council established an Ad Hoc Committee to review and revise the Special Committee Report. The Ad Hoc Committee report on resource and reserve definitions was accepted by CIM Council in February 1996 and, at that time, Council established the Standing Committee on Reserve Definitions.

The Ad Hoc Committee Report was published in the September 1996 CIM Bulletin.

Reserve Definitions revised by CIM Standing Committee

In 1997, the Ontario Securities Commission (OSC) and the Toronto Stock Exchange (TSE) established the Mining Standards Task Force (MSTF) to “review the standards governing the conduct of mineral exploration programs and the disclosure of results” of these programs.

MSTF released a draft report in June 1998 and a final report entitled "Setting New Standards" in January 1999. One of the primary recommendations of the MSTF Report was the "adoption, by the Canadian Securities Administrators (CSA) in National Instrument 43-101 (NI 43-101), of the CIM guidelines for the estimation, classification and reporting of resources and reserves, as amended from time to time".

On July 3, 1998, the CSA published a first draft of National Instrument 43-101 (NI 43-101) as the replacement for National Policy 2-A and National Policy 22. During this period and in consultation with CSA and others, the CIM Standing Committee revised and updated the CIM Definition Standards which were accepted by CIM Council in August 20, 2000.

NI 43-101 came into effect February 1, 2001.

Reserve Definitions reflect detailed guidance

Subsequent to the publishing of the August 20, 2000 CIM Standards on Mineral Resources and Mineral Reserves, various CIM committees have compiled and published more extensive documentation on mining industry standard practices for estimating Mineral Resources, Mineral Reserves and mining studies.

These standard practices provide commodity-specific detailed guidance. On November 14, 2004, CIM Council adopted an update to the CIM Definition Standards to reflect the more detailed guidance available and effect certain editorial changes required to maintain consistency with current regulations. 

The December 13, 2005 version of the CIM Definition Standards included further editorial changes required to maintain compatibility with the new version of NI 43-101. On November 27, 2010 definitions for Pre-Feasibility Study and Feasibility Study were added to the CIM Definition Standards, and these definitions were referenced by National Instrument 43-101 in 2011.

In 2011, the CIM Standing Committee on Mineral Reserve and Mineral Resource Definitions began a major update of the CIM Definition Standards to address recent changes in NI43-101 as well as industry, CSA, CRIRSCO and UN requests for clarification and guidance. In May 2013, the Standing Committee began a 90 day period of Industry, CSA and member consultation.  Following consultation, the committee reviewed and analyzed all comments.   Portions of the proposed definitions and guidance were subsequently modified to address industry concerns. On May 10, 2014, CIM Council adopted the updated CIM Definition Standards.