July 31, 2006: Additional surveys conducted in 2004-2005 resulted in new compilations shown on the 2005 Geophysical Surveys Map.

A 1:250 000 scale geophysical map of Quesnel Lake, compiled using survey data acquired between 1991 and 2005, is available as Geological Survey of Canada, Open File 5295; free Download from GEOSCAN.

View Quesnel Geophysics Map

How the Magnetic and Radiometric Maps Can be Used:

Multiparameter (gamma-ray, magnetic) geophysical surveys are useful in mineral exploration and bedrock mapping studies. In the Quesnel Trough, these surveys are particularly useful in exploring for alkalic porphyry Cu-Au porphyry deposits like Mt. Polley, or related deposits like QR. The potassium, potassium/thorium, magnetic total field and magnetic vertical gradient maps can be used to help identify potassic alteration and magnetite enrichment/depletion zones associated with copper-gold mineralization, and also help in mapping lithologies and structures. For additional information on the GSC NATGAM program and interpretation of radiometric maps, go to  http://gsc.nrcan.gc.ca/gamma/index_e.php.

Survey Summary:

The 1993 Mount Polley survey was flown with the GSC Sky-van fixed wing aircraft. Flight lines were flown in an east-west direction with a line-spacing averaging 500 m. The data was released in 1995 as GSC Open File 2802 by R.B.K. Shives et al.

HORSEFLY MULTISENSOR GEOPHYSICAL SURVEY
Open File 2004-9 / GSC OF 4615 & GSC OF 4616
Helicopter-borne gamma ray spectrometric and magnetic total field geophysical survey, Horsefly Area, British Columbia
(Parts of NTS 93A/3,5,6,11)
Shives, R.B.K., Carson, J.M., Ford, K.L., Holman, P.B., Cathro, M.

IMPERIAL METALS CORP. MOUNT POLLEY 2003 MULTISENSOR GEOPHYSICAL SURVEY
Open File 2004-10 / GSC OF 4619
Helicopter-borne gamma ray spectrometric and magnetic total field geophysical survey,
Imperial Metals Corporation’s Mount Polley Mine area, British Columbia
(Part of NTS 93A/12)
Shives, R.B.K., Carson, J.M., Ford, K.L., Holman, P.B., Cathro, M.

In 2003 Imperial Metals Corporation conducted a multisensor (gamma-ray spectrometric, magnetic total field) helicopter-borne geophysical survey over the Mount Polley Mine area, British Columbia, Canada. Flight lines were oriented east-west, spaced at 100 m intervals. The survey was flown under contract, by Fugro Airborne Surveys. The survey was funded by Imperial Metals Corporation and the British Columbia & Yukon Chamber of Mines "Rocks to Riches" Program.  This data was published as GSC OF 4619 in 2004 and to MapPlace as BCMEM Open File 2005-10 on March 26, 2004.

TISDALL LAKE 2004 MULTISENSOR GEOPHYSICAL SURVEY
Open File 2005-16
Helicopter-borne gamma ray spectrometric and magnetic total field geophysical survey, Tisdall Lake area, British Columbia
(Parts of NTS 92P/15; 93A/2, 3,6,7)
Shives, R.B.K., Carson, J.M., Dumont, R., Holman, P.B., Yeager, D., Geological Survey of Canada

In 2004 the Geological Survey of Canada conducted a multisensor (gamma-ray spectrometric, magnetic total field) helicopter-borne geophysical survey in the Tisdall Lake Area, southeast of Mount Polley, British Columbia, Canada. Flight lines were oriented NE-SW, spaced at 250 m intervals. The survey was flown under contract by Fugro Airborne Surveys. Funding was provided by Amarc Resources Ltd.  Support for the Geological Survey of Canada’s Radiation Geophysics Section, acting as the Scientific Authority for the survey, was provided under Natural Resources Canada – Earth Sciences Sector’s Northern Resources Development Program.

This data was published to MapPlace as BCMEM Open File 2005-16 on April 8, 2005. A full product release (in late spring 2005) will be made by the Geological Survey of Canada as a series of Open Files, including printed colour maps, images of the printed maps in PDF format, and digital line and grid data.

Analogue and digital products include data for eight radiometric and two magnetic parameters:

For information contact

Brian Grant, BC Geological Survey,
B.C. Ministry of Energy, Mines and Petroleum Resources,
PO Box 9333 Stn Prov Govt,
Victoria, B.C.   V8W 9N3
E-mail: Brian.Grant@gov.bc.ca
Telephone: (250) 952-0454 Fax: (250) 952-0381
Website: http://www.em.gov.bc.ca/geology/

3. Available only from the Radiation Geophysics Section in Ottawa, on demand.