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Ministry of Energy Mines and Responsible for Core Review

9. INVENTORY

 

9.1 Inventory Data
9.2 Zone Name
9.3 Inventory Category
      9.3.1. Reserve
      9.3.2 Resource
      9.3.3 Other
9.4 Year
9.5 Sample Type
9.6 Quantity
9.7 Commodity/Grade
9.8 Comments - Inventory   
9.9 Reference

9.1 INVENTORY DATA

 

The MINFILE coding form includes space for information on deposit economics or mineral inventory.

Several parameters affect the qualitative and quantitative reporting of the economic potential of a mineral occurrence. Some of these are the variable reliability of reporting, differences in interpretation of terms, and changing economic conditions.

The Reserve category is used only for an inventory in an operating mine or a mine near production. Ore reserves are reported as Proven, Probable and Possible. The Resource category is used for all other inventories. Resources are reported as Measured, Indicated and Inferred. A combination of categories is reported as Combined. If the category is not known then Unclassified is used. Sample data can be entered using the Assay/Analysis category. The reserves/resources are reported in tonnes with the grade of commodities.

Reserves and resources are not calculated by Ministry of Energy, Mines and Petroleum Resources personnel but are quoted from referenced industry sources and/or publications. Due to differences in identifying categories in the data sources, Ministry personnel may occasionally have to interpret which category the figures are placed into. The reader should refer to the original data for detailed information.

In general, the inventory is identified by occurrence, zone name and year. There may be an unlimited number of ore zones per occurrence. In addition, each zone name may have inventory for each category. Each ore zone can have a maximum of two inventory calculations per year, per category (e.g., Calculation A & B). This allows for changes in calculations due to grade-tonnage relationships; calculation A may be high-grade low tonnage while calculation B may reflect a low-grade tonnage. Generally, only data for the most recent year is maintained in the database. Older data is erased when data for a new year is input. Only one calculation may be used per ore zone in the ASSAY/ANALYSIS category. The ASSAY/ANALYSIS data cannot coexist with reserves information for any given ore zone name.

NOTE: Conversion factors are included in Appendix VII.

 

9.2 ZONE NAME

(*)

(R26-28) (E27)

 

This is the name of the distinct unit or ore zone of a deposit for which a calculation is made. Several zones may be associated with each deposit and may include categories in both the Reserve and Resource fields. If a deposit has only one ore zone or does not distinguish between ore zones, then the name of the deposit is used for the zone name.

When using the ASSAY/ANALYSIS category, the ZONE NAME should be chosen from the generic name list in Appendix XV.

 

9.3 INVENTORY CATEGORY

(*)

(R26,R28) (E29)

 

9.3.1 RESERVE: The Reserve category is used only for a mineral and/or substance inventory in an operating mine or mine near production. Sufficient information is available to form the basis of a preliminary mine production plan. Factors that affect ore reserve estimates are geological, economic, mining, metallurgical, marketing, environmental, social and governmental conditions. Ore reserves are reported as Proven, Probable and Possible.

Proven (PV): Ore reserves are stated in terms of mineable tonnes and grades in which the identified substance has been defined using sufficient metallurgical, mine method, geoscientific, infrastructure, operating and capital cost data. Other applicable reserve adjectives may include measured recoverable, diluted, mineable, ore, or in situ.

Probable (PB): Ore reserves are stated in terms of mineable tonnes and grades where sufficient information is available about the thickness, grade, grade distribution, mineable shape and extent of the deposit. Continuity of mineralization should be clearly established. Other applicable reserve adjectives may include measured geological, drill indicated, or indicated.

Possible (PS): Ore reserves are stated in terms of mineable tonnes and grades computed on the basis of limited geoscientific data, but with a reasonable understanding of the distribution and correlation of the substance in relation to this data. Other applicable reserve adjectives may include inferred, geological, mineral inventory, or potential.

9.3.2 RESOURCE: The Resource category is used for a mineral and/or substance inventory other than an operating mine. Valuable or useful material is quantified on the basis of geoscientific data and expected economic merit. Mine, metallurgical, price and cost data are not necessarily available. In reporting a resource, there is an implication that there are reasonable prospects for eventual economic exploitation. Resources are reported as Measured, Indicated and Inferred.

Measured (MG): Sufficient information is available about the thickness, grade, distribution, mineable shape and extent of the deposit to give defined grade and tonnage figures. Continuity of mineralization should be clearly established. Other applicable resource adjectives may include proven, measured recoverable, diluted, mineable, or in situ.

Indicated (IN): Tonnage and grade are computed partly from detailed sampling procedures and partly from projection for a measurable distance, based on geoscientific data. Sampling procedures are too widely spaced to ensure continuity but close enough to give a reasonable indication of continuity. Other applicable resource adjectives may include probable, measured geological, or drill indicated.

Inferred (IF): An estimate of tonnage and grade computed from geoscientific data or other sampling procedures, but before testing and sampling information is sufficient to allow a more reliable and systematic estimation. Other applicable resource adjectives may include possible, geological, mineral inventory, or potential.

9.3.3 OTHER: These are to be used only if the data cannot be categorized as Reserves or Resources.

Combined (CB): This designation is used when an inventory figure is reported to be a combination of categories (e.g.) PV + PB (Proven and Probable) reserves or MG + IF (Measured and Inferred) resources. It can be applied to both the Reserve and Resource categories.

Unclassified (UN): This designation indicates that the criteria for qualifying the inventory figures are not available. The Unclassified category can be applied to both the Reserve and Resource categories. For example, a tonnage figure is given with grades of commodities, but the category is not stated.

Assay/Analysis (BA): Samples of one or more of the various sample types listed below have been collected and analyzed. This category is reserved for deposits which have no reported inventory figures. The value quoted should normally be representative of a group of samples and is not necessarily the assay containing the highest values. If available the sample size should be identified in the comment field. The 'SAMPLE TYPE' must be identified when using this category.

Unknown (**): This designation indicates that not enough information is available to determine the category.

9.4 YEAR

 (*) (R26,R27)

 

This is the year the inventory figures were published and is mandatory information for any inventory data. If the inventory figures were calculated in any year prior to the official publication date, the source and year of the calculations should be identified in the comment field.

 

9.5 SAMPLE TYPE

(R27) (E28)

 

When the Assay category is chosen, the sample type must be identified using one of the following:

 

CODE SAMPLE TYPE AND DEFINITION
AUGR Auger - a sample taken using and auger.
BULK

Bulk - a large volume sample collected from one or more sites for assay or metallurgical testing. It includes limited sampling or mining in initial production stages for plant site and operations testing.

CHIP

Chip - a large number of small chips or specimens collected over a specific area.

CHNL

Channel - a sample of all material collected from a channel of specific dimensions across a sample site.

DIAD

Drill Core - a split or other type of drill core sample.

GRAB

Grab - a single sample normally selected to represent either high or low grade material.

ROCK

Rock - this may be a chip, channel or grab sample which has been analyzed by standard geochemical techniques rather than assay techniques.

TRNC Trench - a sample taken from a trench.
****

Unknown - This may only be used when the data is important and needs to be included but the sample type is not known.

 

9.6 QUANTITY

(*)

(R26)

 

Reserves or resources must be quoted in metric tonnes. General or approximate figures are only acceptable where no other information is available; this should be clearly explained in the comment field. This is not filled in for Assays.

 

9.7 COMMODITY/GRADE(*)

(R28)

 

The inventory information can have data on up to six commodities. These should reflect only those commodities which can be recovered from a deposit. Minor or accessory commodities of economic interest can be identified in the commodities field of the Mineral Occurrence section.

Commodities are entered by selecting from the Commodities table (see Appendix II) followed by the grade (precious metals in grams per metric tonne, other commodities as per cent). Some industrial minerals may be quoted in kilograms. Commodities entered in the inventory data field, must first exist as commodities in the Mineral Occurrence section of the database. In many of the reports, the commodities are indicated by the standard two-letter, elemental chemical symbol or two-letter codes (see Appendix II); these are also used when searching for commodities.

 

9.8 COMMENTS - INVENTORY

(C11)

 

This is a 70-character, free-format field to identify information on cutoff grades or other data pertinent to the final figures. Unlimited lines are allowed.

 

9.9 REFERENCE

(*)

(C12)

 

The source of the inventory figures is mandatory. Avoid using abbreviations to minimize confusion on the source of the reference. When necessary, an abbreviated format for the reference, similar to the bibliography, is acceptable. One, 70-character line is allowed.