Identified Resources
.—Resources whose location, grade, quality, and quantity are
known or estimated from specific geologic evidence. Identified resources include
economic, marginally economic, and sub-economic components. To reflect varying
degrees of geologic certainty, these economic divisions can be subdivided into measured,
indicated, and inferred. Demonstrated.—A term for the sum of measured plus indicated.
Measured
.—Quantity is computed from dimensions revealed in outcrops,
trenches, workings, or drill holes; grade and/or quality are computed from
the results of detailed sampling. The sites for inspection, sampling, and
measurements are spaced so closely and the geologic character is so well
defined that size, shape, depth, and mineral content of the resource are
well established.
Indicated
.—Quantity and grade and/or quality are computed from
information similar to that used for measured resources, but the sites for
inspection, sampling, measurement are farther apart or are otherwise less
adequately spaced. The degree of assurance, although lower than that for
measured resources, is high enough to assume continuity between points
of observation.
Inferred
.—Estimates are based on an assumed continuity beyond
