Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
14-17
14.8 Grade-Zoned Composite Statistics
Basic statistics and grade distributions for TREO are shown in Table 14.11 and
Figure 14.9, and indicate that the grade-zoning process partitions TREO into high-
grade and low-grade populations.
The distribution of high-grade TREO is nearly lognormal, as shown by the nearly
straight line in the lognormal cumulative frequency distribution. About 75% of the
high-grade composites are above 1.5% TREO; an additional 25% of the composites
are internal low-grade zones that are included to makeup the minimum mining width.
Less than 3% of the low-grade OreZONE are above 1.5% TREO, and those
composites represent patchy higher-grade stockwork mineralization.
The TREO OreZONE partitions also subdivide the distributions of FMR, iron oxide,
manganese oxide, thorium, and uranium abundances into higher-grade and lower-
grade populations, as shown in Figure 14.10, although the process is less efficient,
and the ratio of grades in the high-grade OreZONE to the low-grade OreZONE is
lower than for TREO. In addition, thorium shows a higher-grade population in the
low-grade OreZONE that is attributable to higher thorium grades in the Whitetail
deposit.
The TREO OreZONEs do not effectively partition CaO, however, as oxide type is the
dominant factor in the CaO distribution. As shown in Figure 14.11, TREO OreZONE
codes effectively partition the OxCa zone into low and high-grade CaO, but leaching
of carbonates in the oxide zone reduces CaO grade to a level that is similar
regardless of the TREO OreZONE code. A small number of high CaO assays in the
oxide zone and low CaO assays in the OxCa zone are observed and should be
checked in the next version of the model.
