120
σ r
Panel Standard Deviation
Panel Mea
M M n
=
× 100%
Relative
confidence limit
r
90
1 645
12
15
%
.
%
= ±
×
<
σ
As in the kriging-based approach, this still assumes an underlying normal distribution for
an annual production of 12  months with similar grade distributions. The simplicity of this
approach is that it avoids the construction of a large scale model to assess multiple periods of
annual production in order to make confidence interval statements relevant for an Indicated category
assignment. The assumption of normality permits assignment of the monthly panel to an Indicated category assuming independence between 12 monthly panels of similar distributions.
Figure  3. (a) Simulated panel grades in three realizations; (b) Distribution of the simulated panel
grades in one panel with its conditional mean and standard deviation.
Figure 4. Indicated and Inferred category on an open pit bench within the pit area: (a) Indicated category
blocks and panels; (b) panel categories based on simulation: Inferred (dashed line) and Indicated (thick line).
-
(a)
(b)