Survey Metadata

In July 2005, helicopter-supported stream sediment and water sampling was carried out in the Horn Plateau area, Northwest Territories.  The survey area coincided with NWT’s Edéhzíe candidate protected area.  A total of 357 sites were sampled, covering approximately 19,600 km² of the roughly 25,000 km² candidate area.  The sampling density in the southeast is lower than the rest of the area.  The rest of the candidate protected area was sampled in an earlier survey, completed in 2003 and released in Geological Survey of Canada Open File 4674.

The data from both 2003 and 2005 are published in Geological Survey of Canada Open File 5478.

This survey was carried out using National Geochemical Reconnaissance (NGR) protocols.

NGR stream sediment, water and HMC

At each site a pre-labelled Kraft paper bag was two-thirds filled with silt or fine sand collected from the active stream channel.  In practice, the silt sample was collected after water samples were collected but before a bulk sediment sample.  Handfuls of silt from various points in the active stream channel were collected while gradually moving upstream.  A moss mat sample was sometimes collected when a suitable sample was scarce or absent.

At every site, waters were sampled mid-channel, from flowing water where possible.  At sites where sediments were taken for heavy mineral concentration (approximately every second site) two water samples were generally collected.  Samples were collected in 125 mL Nalgene bottles.  The bottles were rinsed two or three times before collecting the sample.

Material for heavy mineral concentrates was collected from the upstream points of mid-channel bars, at a single point where possible.  Material was wet-sieved through a 12-mesh stainless steel sieve into a 5-gallon plastic pail lined with a heavy-duty plastic bag until a sample weight of 10-15 kg was attained.