Survey Metadata

In August 2003, helicopter-supported stream sediment and water sampling was carried out in the lower Willowlake River area of the Northwest Territories.  The survey area coincided with a western portion of the NWT’s Edéhzíe candidate protected area.  A total of 260 sites were sampled, covering approximately 5,400 km² of the roughly 25,000 km² candidate area.

The data, including mineralogical and kimberlite indicator mineral electron microprobe data and analytical data for HMCs from 102 sites, are published in Geological Survey of Canada Open File 4674.

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.