What is Mineral Resource Assessment Level 2 Data:  The data are downloadable as shape files or e00 files of mineral potential tracts for British Columbia.  The tracts are also displayed as a layer on MapPlace.  The tracts were defined originally during the 1992-1997 mineral potential project (MRA1).  Tract boundaries are based on underlying bedrock geology.  Several tracts in the coastal area of BC were considered to be too large (>100,000 Ha) and were subsequently subdivided and reanalyzed for the Coast Information Team (MacIntyre et al).  Results of this analysis have been reintegrated with the full provincial database (MRA2).

Gross values for known and undiscovered resources are assigned to each tract as well as relative tract ranking for both metallic and industrial (non-metallic, non-energy) minerals.  The industrial mineral values are currently not available. Detailed metadata for the files are in preparation and will be contained in MRA2_meta.doc.

Constraints on use/interpretation: Mineral Resource Assessment maps and products are a very valuable component in any land use planning process.  In jurisdictions containing substantial mineral resources such as British Columbia they are essential.  Although considered essential to the process they are only a component of the information needed to make an informed decision on land use.  There are a number of limitations to any Mineral Resource Assessment product.

1) The principle limitation is the timeliness of the assessment.  All assessments are made based on historic information and current knowledge.  They are therefore, a snapshot in time.  They cannot be expected to accurately portray the mineral potential of a portion of land far into the future.  Our knowledge of mineral deposits will advance with time, changing our ability to discover and develop deposits in unimagined environments, at greater depths and with lower grades.  New technologies will allow certain deposit types to be discovered with greater ease and will allow the profitable exploitation of deposits that are currently uneconomic.  In addition, deposit types that were not believed to exist in the study area during the analysis may subsequently be found within the area.  Societal demands for certain commodities will change causing the relative values of deposits to change and thus the relative ranking of mineral assessment tracts.

2) The Level 1 MRA was conducted at a scale of 1:250 000 to inform regional scale planning.  However, as the planning process progressed, smaller and smaller study areas were proposed and land use planning initiated.  In some LRMP areas only a few 1:250 000 scale mineral assessment tracts covered the whole LRMP.  In these small areas an analysis of greater detail than the initial 1:250 000 study is required to be able to make any reasonable contribution with respect to mineral potential.  The MRA2 data attempt to do this, at least in the coastal area of BC. Scale constraints still apply to other areas of the province.

3) The mineral assessment evaluation was carried out on a regional basis and tract rankings are relative and not absolute.  Comparison of tract rankings from widely separated regions may result in flawed analysis due to their very different histories.  Two tracts may have exactly the same mineral potential but due to the remote location of one relative to the other it will not have received the exploration attention over time and will likely have a lower mineral potential ranking than the tract that received the most exploration.  Detailed comparison of tract rankings within a region or closely separated tracts in two adjacent regions is valid, as they will in most cases have shared a common exploration and developmental history.

Advice on depiction – legendizing data: Two maps are needed to depict the MRA2, based upon the relative ranking (1 for lowest; 907 for highest) for metallic or industrial mineral commodities.  The different natures of these two commodity types and the determination of their rankings precludes combining them.

For each commodity type, the tracts should be grouped into a minimum of five categories and preferably 10 for the whole province.  The divisions between categories must be based upon the percentage of total area (i.e. category 1 = the 20% of the province with the highest tract rankings; etc.).  Other groupings are discouraged.