Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
14-24
coordinates were multiplied by a factor of 10 for variogram calculation to minimize the
contribution of the Z component to variograms in the XY space. The distances for the
Z-axis variograms were divided by 10 for fitting of variogram models, restoring them
to the original scaling.
TREO and other grade variograms were computed using log-transformed
correlograms within the high-grade and low-grade OreZONEs independently. Only
data from the oxide and OxCa zones were used for variogram calculation.
Variograms for %CaO were subdivided into oxide and OxCa as well as OreZONE.
Variograms for the OreZONE indicator variable were computed using correlograms
without any transformation of the zero/one (0,1) indicator. Only those composites
from the oxide and OxCa zone were used for experimental variogram calculation. The
resulting variograms are summarized in Table 14.15.
Variogram models were fitted to the experimental variograms using Sage and up to
two nested, exponential variograms. The traditional convention for the exponential
variogram range was used, which is approximately one-third of the practical range.
Experimental variograms and models are shown for directions closest to the principal
variogram axes in Figure 14.12 through Figure 14.16.
F-function values for 20x20x20-foot blocks were computed for each variogram for
later use in validating the grade estimation. The F-function value is equal to the
variance of samples within a block of a particular size and shape. Smoothing factors,
which are the variance reduction factors that would be expected when moving from
the distribution of samples to the distribution of blocks are listed in Table 14.15.
