Geofile 2006-11 (Geoscience BC Report 2006-4) reports new regional geochemical drainage sediment – water survey data from the Anahim Lake (NTS 93C) and Nechako River (93F) map sheets. This digital release consists of a survey summary, data listings, statistics and maps in PDF format, plus ZIP files with raw data files in XLS and DBF formats and base data in GIS importable shape files.

There are over 60 base and precious metal occurrences in the Anahim Lake - Nechako River map sheets including several such as the 3T’s and Clisbako, which have extensive exploration history. However, exploration for new deposits has been hampered by widespread glacial sediment and Miocene lava cover. During 2005 a total of 2070 drainage sediment and water samples were collected from 1957 sites covering 19 500 square kilometres. Most of the samples were taken from lakes and analysed for trace and minor elements by instrumental neutron activation and by aqua regia digestion - inductively coupled plasma mass spectrometry (ICP/MS), for loss on ignition (LOI) and for fluorine. Water samples were analysed for pH, conductivity and fluoride. Survey data has been combined with the results of two previous lake sediment and water geochemical surveys (Open File 1994-19) completed near the Fawnie Range and around Ootsa Lake. Gold values up to 694 ppb and copper up to 1536 ppm have been detected in sediment samples.

The 2005 surveys were fully funded by Geoscience BC (Contribution Number GBC016).

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