Purpose
The assessment of resource values is an important government responsibility as
communities attempt to balance environmental goals with responsible development
initiatives. In Yukon, land is under increasing pressure from competing and commonly
conflicting interests. Mineral Resource Assessments provide a scientific perspective
on mineral potential for a variety of land use planning processes.
The purpose of a Mineral Resource Assessment is to estimate the relative mineral
potential of an area before making land use decisions that might affect the amount and
type of activity permitted in that area. Incorporating essential information on mineral
resources within a multidisciplinary approach to planning contributes to informed and
balanced decision making. Potential conflict may be avoided and conservation objectives
may be met while still preserving access to resources.
Mineral Resource Assessments evaluate the potential of a region to host mineral deposits
and are based on the compilation of the best available geological data. A panel of
professional geologists estimates the resource potential of different tracts of land,
based on characteristics of individual mineral deposit types. A mineral potential map
displays the results of the assessment by showing the relative mineral potential of
different parts of the area under study.
Methodology
Mineral assessments in Yukon are done using a similar method to that used by the
British Columbia Geological Survey and United States Geological Survey and are
designed to assess potential for more than 40 different types of metallic and
industrial minerals including coal. Many of these
mineral deposit profiles are
available for download. Potential for oil and gas resources are assessed in a separate process.
Figure 1. North Yukon mineral assessment 2004.
Assessments consist of: (1) compilation of available geoscientific data and pertinent mineral
deposit models; (2) identification of gaps in the geoscientific database; (3) additional fieldwork
and final data compilation; (4) definition of areas of similar geology called tracts; and
(5) evaluation of individual tracts by a panel of professional geologists. Evaluations of a
tract are estimates of the probability for the occurrence of one or more mineral deposits of a
specific size and type in the tract. One or more of the geology, the type of mineral showings,
the geochemical signature or the geophysical signature may indicate a favourable environment
for the occurrence of a specific mineral deposit type in the tract.
Assessments are done on regional and detailed scales. The methodology is similar for both
scales, up until the final assessment stage. For regional assessments, evaluations are entered
into a Monte Carlo simulator program and converted to probability graphs. The program then
combines the estimates with grade and tonnage data for one or more specific mineral deposit
types to predict the amount of individual commodities and thus the total value of the mineral
esources in that tract. This value is highly speculative and will never be realized by future
mineral development, but can be effectively used to compare one tract to another. For detailed
assessments, panelists rank the tracts with respect to one another without the probabilistic estimation.
The final product is an overall relative ranking of the tracts displayed as a mineral potential map.
Figure 2. Mineral potential map of the North Yukon planning region.
Limitations
Mineral assessments are based on the best geoscientific information available at the time of the study.
Assessments must be revised as knowledge of the geology of an area and the types of mineral deposits that
could occur within that area improves. This type of study represents a "best estimate at the time" on
resources that are hidden in the ground and cannot be quantified. Conclusions derived from such a study
are only as sound as the data that are available for the evaluation.
Projects
Six regional-scale assessments have been conducted to date, which cover the entire Yukon with the
exception of a region in southwest Yukon that includes Kluane Park. Currently, regional assessments
are in progress for two large areas in North Yukon to provide accurate mineral potential data for regional
land use planning processes. Detailed or site-specific assessments are complete or in progress for several
existing and proposed Special Management Areas.
Conclusions
Mineral potential maps provide a comparative ranking of an area that reflects current thinking on
geological favourability for specific mineral deposit types. Maps are derived by a sound, scientifically
rigorous and reproducible method that supports the land-use planning process by providing decision-makers
with factual information on existing and potential mineral resources. The mineral assessment process is
recognized and used in other jurisdictions to assist land-use planning.
For more information on MRAs, please contact:
Lee Pigage
