NT GoMap
Detailed Reference Report
Cover Information
Megatype Government Scientific Publication; NTGO Publication
Type EGS Open Report
Number 1999-002
Filing/Pub Date 1999-11-01
Release Date
Title Extech III: Biogeochemical Survey, Yellowknife Area 1999, NTS 85J/9 (Outer Spruce Bark and Labrador Tea Stems)
Author Nickerson D
Territory NWT
NTS 085J09
Bounding Box
Latitude min: 62.5
max: 62.75
Longitude min: -114.5
max: -114
Geographic Area Yellowknife
Period of Work From To
Target(s) of Exploration Gold
Publisher Dept. Indian Affairs and Northern Development, NWT Geology Division
Availablity Distributed by NTGO
Medium Digital File(s) 4.3 MB in 8 files; 14 page report as Word 95 or PDF, 5 tables in Excel, 1 cpt file.
Miscellaneous Exploration
No Digital Data
Comment Biogeochemical methods were used to assess gold or other metals potential and delineate target areas for more detailed exploration. Preliminary examination had shown that black spruce (Picea mariana) and labrador tea (Ledum groenlandicum) were ubiquitous and with the fore-knowledge that both these species accumulated gold and other metals of interest, it was decided to use the outer bark of the former and the stems of the latter as sampling media. Samples were collected by hand using simple tools. After drying, the samples were ashed and the ash analysed by both INAA and ICP by Activation Laboratories Ltd. of Ancaster, Ontario. This report contains a compilation of results which demonstrate that the technique is workable although of reduced effectiveness in proximity to the existing mining operations due to widespread gold and arsenic contamination. Good results were obtained in connection with a small base metal showing at Homer Lake, and some very limited initial work was done to see if the same technique could be applied to diamond exploration.

Activity Lab Work / Physical Properties
Details Method/Medium Scale of Work
Activity Sampling
Comment Outer bark and labrador tea stem samples were collected. Care was taken to collect bark from the entire circumference of the tree, not just from one side. Samples were taken somewhere between 0.5m to 2.0m above ground level. The stems were generally about 40cm long and were manually stripped of flowers and leaves before being cut up into pieces some 5 cm long to facilitate their placement into sample bags and further processing. In a similar fashion to that described above, a number of plants from, if possible, several growth areas were taken at each location. At each site, observations were made and recorded as to apparent depth of overburden. Before being shipped out for analysis the samples were dried for several days in a clean drying room maintained between 40 and 45?C. Labrador tea stems lost about half of their field weight as a result of drying but the loss with spruce bark was considerably less. Ashing and analysis were both performed by Activation Laboratories Ltd. of Ancaster, Ontario. Samples were ashed for 24 hours at 475?C in a specially dedicated oven. The principal method of analysis employed was instrument neutron activation analysis using a one gram or thereabouts sample of ash. Because INAA does not determine copper and certain other elements of interest, 0.25g of ash was digested in aqua regia and analysed on a Perkin Elmer Optima 3000 ICP to provide these additional values.
Details Method/Medium Scale of Work
Plant Grid/Target/Local Sampling

Associated Occurrences



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