technical report on the nechalacho deposit, thor lake project ...

14. DATA VERIFICATION
QUALITY ASSURANCE / QUALITY CONTROL
In 2007, Avalon commissioned CDN Laboratory from British Columbia to generate three
standards called AVL-H, AVL-M or AVL-L. These standards would be inserted into the assay
stream. Avalon then commissioned Dr. Barry Smee to review the round robin and assess the
quality of the data.
In 2010, Avalon commissioned CDN Laboratory from British Columbia to generate a further
standard called S-04-09. This standard would be inserted into the assay stream, alternating
with the original three standards. Avalon then commissioned Dr. Barry Smee to review the
round robin and assess the quality of the data. The Round Robin on the new standard included
samples of the original three standards, rare earth certified standards, all randomized for the
Round Robin. When inserted into the sample database, this standard was referred to as STD-
H2.
The statistics of QAQC control samples was presented previously in the Scott Wilson RPA
(2010) and is updated here. The control samples inserted into the sample stream from drill
holes 137 to 311 are presented in Table 14-1.
Table 14-1 Statistics of QAQC Control Samples, L09-137 to L10-311
Samples Analyses Blanks Standard-L Standard-M Standard-H Standard-H2 Standards total
Total number 10,491 15,474 417 180 162 121 306 769
Percent of samples 4.0% 1.7% 1.5% 1.2% 2.9% 7.3%
Percent of analyses 2.7% 1.2% 1.0% 0.8% 2.0% 5.0%
As can be seen, blanks were inserted on average at the rate of 4.0%, or one in 25 samples, and
standards at the rate of 7.3%, or one in 13 samples. The rate of insertion of standards was
varied according to whether the samples were from a mineralized zone or not with a standard
every 10 samples in mineralization and every 40 samples outside mineralization. Some 10,491
samples were analysed by ALS method MS81 (so called “regular” analysis) and some 4,983, or
47%, were re-analysed for method MS81H, for higher rare earth and Zr analytical limits. As
noted elsewhere, samples were also analysed for additional methods such as tests of XRF
analysis for Zr, Nb and Ta. These additional analyses are not included in the statistics above.
The results of the standard analyses were checked against the certified or provisional means
and tolerances listed in the standard certificates as well as against the lab’s (ALS) own precision
tolerance level of +/-10%. The three rare earth elements with the potential highest value (Nd,
Technical Report 43-101 – March 13, 2011 Page 14-1
Prepared by Avalon Rare Metals Inc.