JORC definitions

The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves 2012 edition (JORC Code), is an internationally recognized professional code of practice that sets minimum standards for the public reporting of exploration results, mineral resources and ore reserves. Below are the precise definitions of JORC terminology:

The JORC Code provides a system for the classification and reporting of mineral resources and ore reserves according to the levels of confidence in geological knowledge and technical and economic considerations (as shown in the JORC Code 2012 visual, on page 63). The key principles governing the application of the JORC Code are transparency, materiality and competence.

Transparency requires that the reader of a report is provided with sufficient information, in a clear and unambiguous form, to understand the report. Materiality requires that it contains all the relevant information that investors would reasonably require in the reporting of mineral resources or ore reserves.  Competence requires that the public reporting of mineral resources and ore reserves is prepared and certified by suitably qualified and experienced persons, called Competent Persons.

Mineral resources and ore reserves reported according to the JORC Code must accurately reflect the information and supporting documentation prepared by a Competent Person who is subject to an enforceable professional code of ethics by a recognized professional organization. A company issuing a public report prepared by a Competent Person is also required to identify the person, reveal if the person is a full-time employee, and if not, disclose the name of the person’s employer.

Mineral resource is a concentration or occurrence of material of economic interest in or on the Earth’s crust in such form, grade/quality and quantity that there are reasonable prospects for eventual economic extraction. The location, quantity, grade, continuity and other geological characteristics of a mineral resource are known, estimated or interpreted from specific geological evidence and knowledge, including sampling. Mineral resources are sub-divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories.

Inferred mineral resource is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of limited geological evidence and sampling. Geological evidence is sufficient to imply but not verify geological and grade continuity.

It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes.An Inferred Resource has a lower level of confidence than that applying to an Indicated Mineral Resource and must not be converted to an Ore Reserve. It is reasonably expected that the majority of Inferred mineral resources could be upgraded to Indicated mineral resources with continued exploration.

Indicated mineral resource is that part of a mineral resource for which quantity, grade or quality, densities, shape and physical characteristics are estimated with sufficient confidence to allow the application of Modifying factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. Geological evidence is derived from adequately detailed and reliable exploration, sampling and testing gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes, and is sufficient to assume geological and grade/quality continuity between points where data and samples are gathered. An Indicated mineral resource has a lower level of confidence than that applying to a Measured mineral resource and may only be converted to a Probable ore reserve.

Modifying factors are considerations used to convert mineral resources to ore reserves. These include, but are not restricted to mining, processing, metallurgical, infrastructure, economic, marketing, legal, environmental, social and governmental factors.

Ore reserve is the economically mineable part of a Measured and/or Indicated mineral resource. It includes diluting materials and allowances for losses, which may occur when the material is mined or extracted and is defined by studies at Pre-feasibility or feasibility level, as appropriate, that include application of Modifying factors.Such studies demonstrate that, at the time of reporting, extraction could reasonably be justified. The key underlying assumptions and outcomes of the Pre-feasibility study or

Feasibility study must be disclosed at the time of reporting of a new or materially changed ore reserve. Ore reserves are sub-divided in order of increasing confidence into Probable and Proved.

Probable ore reserve is the economically mineable part of an Indicated, and in some circumstances, a Measured mineral resource. The confidence in the Modifying factors applying to a Probable ore reserve is lower than that applying to a Proved ore reserve. A Probable ore reserve has a lower level of confidence than a Proved ore reserve but is of sufficient quality to serve as the basis for a decision on the development of the deposit. 

Probable ore reserve is the economically mineable part of an Indicated, and in some circumstances, a Measured mineral resource. The confidence in the Modifying factors applying to a Probable ore reserve is lower than that applying to a Proved ore reserve. A Probable ore reserve has a lower level of confidence than a Proved ore reserve but is of sufficient quality to serve as the basis for a decision on the development of the deposit.

Proved ore reserve is the economically mineable part of a Measured mineral resource. A Proved ore reserve implies a high degree of confidence in the Modifying Factors. A Proved ore reserve represents the highest confidence category of reserve estimate. The style of mineralization or other factors could mean that Proved ore reserves are not achievable in some deposits.

Competent Person is a minerals industry professional who is a member or fellow of The Australasian Institute of Mining and Metallurgy, or of the Australian Institute of Geoscientists, or of a Recognized Professional Organization, as included in a list available on the JORC and Australian Stock Exchange websites. These organizations have enforceable disciplinary processes including the powers to suspend or expel a member. A Competent Person must have a minimum of five years relevant experience in the style of mineralization or type of deposit under consideration and in the activity which that person is undertaking.