The MapPlace - Toodoggone Geophysics
and Geology Map
(BCMEM OF
2004-8 / GSC OF 4606 - 4613) |
 |
| Details: The
Toodoggone map features new multisensor, airborne geophysical surveys, which includes
2 magnetic
and 8 radiometric parameters. The files are also available for download
in georeferenced TIF and PNG formats and GeoSoft gridded data (.grd)
format. The 2003
surveys, including the Horsefly/Mount Polley
Geophysics, were posted to MapPlace March 26, 2004.
View
Toodoggone Geophysics Map
Survey Background
TOODOGGONE
MULTISENSOR GEOPHYSICAL SURVEY
Open
File 2004-8
Helicopter-borne gamma ray spectrometric and magnetic total field
geophysical survey, Toodoggone Area, British Columbia
(Parts of NTS 94D/15, E/2,3,6,7,10,11)
R.B.K. Shives, J.M. Carson, K.L. Ford, P.B.
Holman, L. Diakow
In 2003 the BC Ministry of Energy, Mines and Petroleum Resources and the Geological Survey of Canada conducted a multisensor
(gamma-ray spectrometric, magnetic total field) helicopter-borne
geophysical survey in the Toodoggone area, British Columbia, Canada.
Flight lines were oriented NE-SW, spaced at 400 m intervals. The survey
was flown under contract, by Fugro Airborne Surveys. The survey was funded
by the British Columbia Ministry of Energy, Mines and Petroleum Resources and Natural Resources
Canada through the Targeted Geoscience Initiative, and by a consortium of
companies including Bishop Resources Inc., Finlay Minerals Ltd., Northgate
Exploration Ltd., Sable Resources Ltd.,and Stealth Minerals Ltd.
The
overall purpose of the surveys is to provide modern high-definition
radiometric and magnetic data that can be used in the assessment and
development of targets for mineral exploration, and to assist in future
bedrock and surficial mapping studies. The Geological Survey of Canada has
had good results in previous multisensor surveys over similar BC porphyry
deposits (e.g. Afton and Mt. Milligan). The radiometric (K and eTh/K
ratio) and magnetic (total field and calculated vertical gradient) maps
are particularly useful in identifying potassic alteration and magnetite
enrichment/depletion zones associated with these copper-gold deposits, and
in mapping bedrock lithologies and structures.The surveys were completed during August and
September 2003 using an Aerospatiale AS350 helicopter. The flight path was
recovered using a post-flight differential Global Positioning System. A
vertically mounted video camera was used for verification of the flight
path. The traverse lines were flown at an average spacing of 400 m for
Toodoggone, (500 m for Horsefly and 100 m for Imperial Mt. Polley) with
control lines flown at 4000 m intervals (2000 m for Imperial Mt. Polley).
Helicopter flight height was maintained at an average ground clearance of
135 m (60 m).
The gamma ray spectrometry data were recorded at a
1.0 second sample rate using a 256-channel Exploranium GR820 spectrometry
system with 33.6 liters of downward-looking and 4.2 liters of
upward-looking sodium iodide detectors. The aeromagnetic data were
recorded at a 0.1 second sample rate using a 0.01 nT split-beam line
cesium vapour magnetometer suspended below the helicopter.
Final results will be presented in GSC and BCGS Open
File formats in May 2004. The Open Files will consist of digital data (Geosoft
compatible line and gridded formats) and colour interval maps at
1:20,000 and 1:50,000 scales, for 10 layers (listed below). Map images
will be presented as georeferenced .tif files for easy import into GIS
programs and as .pdf files with marginal notes, legend and topographic
base information. Data will be made available for purchase as digital line
or grid data on CD-ROM (from GSC only), in paper format as print-on-demand
colour maps from GSC (only) and as web-viewable, downloadable images in PDF format, at no cost,
from BCGS and GSC-NATGAM websites.
Analogue and digital products
include data for eight radiometric and two magnetic parameters:
| MapPlace Layer
Themes |
PDF
Themes Files
See Note 1 |
| MTF - Magnetic total
field (nT) |
T_mtf.pdf
(4.1 MB) |
|
CVG -
Calculated magnetic vertical gradient (computed, nT/m) |
T_cvg.pdf
(4.4 MB) |
|
POT -
Potassium (K, %) |
T_pot.pdf
(4.1 MB) |
|
URA -
equivalent Uranium (eU, ppm) |
T_ura.pdf
(4.4 MB) |
|
THO - equivalent Thorium (eTh, ppm) |
T_tho.pdf
(4.3 MB) |
|
ADRN -
Natural air absorbed dose rate (ADRN, nGy/h) |
T_adrn.pdf
(4.1 MB) |
|
RUT -
equivalent Uranium/equivalent Thorium (eU/eTh) |
T_rut.pdf
(4.4 MB) |
|
RUK - e
quivalent Uranium/Potassium (eU/K, ppm/%) |
T_ruk.pdf
(4.4 MB) |
|
RTK - e
quivalent Thorium/Potassium (eTh/K, ppm/%) |
T_rtk.pdf
(4.3 MB) |
|
TER - Ternary
radioelement map (K, eU, eTh) |
T_ter.pdf
(3.9 MB) |
| 1:250K Scale Geology, Mineral Occurrences &
Titles |
T_geology.pdf
(0.5 MB) |
| All Themes in one file (11 by 17 images) |
T_geophysics.pdf
(9.8 MB) |
|
GSC Open Files
4606 -
4612 |
Final Product Release |
| Plot size PDF |
1:50K,
1:250K |
| File
Downloads |
Zip
Files |
| Georeferenced TIFF files (UTM Zone 9 NAD 83) |
T_tif_Z9.zip
(4.3 MB) |
| Georeferenced TIFF files (Albers NAD 83) |
T_tif_AL.zip
(4.0 MB) |
| Georeferenced PNG files (UTM Zone 9 NAD 83) |
T_png_Z9.zip
(2.3 MB) |
| Georeferenced PNG files (Albers NAD 83) |
T_png_AL.zip
(2.2 MB) |
| Original GSC SurView data files for viewing and
printing only (.gri & .grx) |
T_gri.zip
(8.4 MB) |
| Original GSC
GeoSoft gridded data format (.grd) |
T_grid.zip
(7.6 MB) |
| Original GSC
Ternary data (.bil), see Note 2 |
T_ternary.zip
(1.0 MB) |
Note 1: The PDF maps were created from
MapPlace using the Rasterize print job option to
eliminate the black background. The TIF and PNG download images include
the geophysical information without topographic base
information.
Note 2: To display the Ternary images
using
Geosoft's
Oasis Montaj the following instructions will
yield the best results.
 | In Oasis, select the grid pulldown menu. |
| select Display grid as Ternary image |
| Colour model must = RGB |
| Colouring method must = Linear |
| The three colour component files must be opened as Files
of Type BIL with *.hdr header. |
| Red-Cyan = TERURA_C.BIL |
| Green-Magenta - TERPOT_M.BIL |
| Blue-Yellow = TERTHO_Y.BIL |
| Shading grid = nothing |
| Shading grid colouring method = Linear |
| To display the triangular Ternary Legend select Display
grid - Ternary Legend |
| Colour model must = CMY |
If these instructions are not followed, the resulting image
will be a three colour image but not the intended GSC style
image. These ternary images should not be treated as data. The
derivation of the colours involves multiple histogram
equalizations.
|
Legend:
K - potassium, i.e. K40 (units: %)
eU - equivalent uranium concentration by weight (the spectrometer
directly measures Bi214, that is an indirect measure of uranium) (units:
ppm)
eTh - equivalent thorium concentration by weight (the
spectrometer directly measures Tl208, that is an indirect measure of
thorium) (units: ppm)
Total Count - all counts from 400 to 3000 keV. (units: cps or uR/h)
Natural Exposure - computed from K (%), eU (ppm), eTh (ppm)
concentrations:
Exposure = 1.505 K + 0.625 eU + 0.31 eTh (uR/h)
(Grasty et al, 1984) 'Exposure' is different from the traditional 'Total
Count', in that it excludes radiation from man-made contaminants.
Natural Air Absorbed Dose Rate - computed from K (%), eU (ppm),
eTh (ppm) concentrations:
Absorbed Dose Rate = 13.08 K + 5.43 eU + 2.69 eTh (nGy/h) 'Natural Air
Absorbed Dose Rate' is different from the traditional 'Total Count', in
that it excludes radiation from man-made contaminants.
eU/eTh, eU/K, eTh/K - ratios of K, eU, eTh that are useful for
interpretation
|
Units:
nT - unit of magnetic total field (nano Tesla)
ppm - unit of concentration by weight (part per million), used
for eU (uranium) and eTh (thorium)
% - for potassium (K40): unit of concentration by weight
Ur - unit of radioelement concentration by weight
(1 Ur is defined as the total count rate from 1 ppm uranium in
equilibrium)
µR/h - unit of Exposure (micro Roentgen/hour)
nGy/h - unit of Natural Air Absorbed Dose Rate (nano Gray/hour)
|
British Columbia Mineral Tenure Information
Clients are reminded that accurate
and up-to-date mineral tenure maps are the paper (counter) maps
at the Mining Recorder's (Government Agent) offices. The claim
information on the MapPlace MTO layer is current to the previous
day. The PDF
maps (Ministry of Sustainable Resource Management) are
out-of-date and should not be relied upon for staking decisions.
The Toodoggone survey is within the Omineca and Liard Mining
Divisions and maps are available from the Mining Recorder's
offices in Smithers (Omineca MD) and Vancouver (Liard MD).
The BCGS (TRIM) claim maps relevant for the Toodoggone
Geophysical Surveys are: 094D.087, 097; 94E.006-007, 014-017, 024-027,
033-037, 043-047, 053-056, 065.
Locations
to View Paper Maps
Vancouver Mineral Development Office, BC Ministry of Energy, Mines and Petroleum Resources
300 - 865 Hornby Street, Vancouver, B.C.
Contact Tom Schroeter, Senior Regional Geologist, 604 660-2812
or Larry Diakow, Senior Project Geologist, 250 952-0430
Mining Operations Branch, BC Ministry of Energy, Mines and Petroleum Resources
162 Oriole Road, Kamloops, B.C.
Contact: Mike Cathro, Regional Geologist, 250 371-6069
Mining Operations Branch, BC Ministry of Energy, Mines and Petroleum Resources
3793 Alfred Avenue, Prince George, B.C.
Contact: Bob Lane, Regional Geologist, 250 561-5606
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/
* * * FINAL PRODUCT
RELEASE * * *
The Geological
Survey of Canada and the BC Ministry of Energy, Mines and Petroleum Resources provided multisensor geophysical survey data for these surveys available in variety
of digital and printed formats in January 2005:
1. Available from GSC offices in Vancouver & Ottawa on demand
| 1:50 000 scale colour interval, hardcopy maps |
| 1:250 000 scale colour interval hardcopy maps |
2. Available from GSC Offices in Vancouver, Ottawa and Crown
Publications Ltd. in Victoria, or download from
MapPlace:
| Digital images of colour interval maps on CD-ROM
in Portable Document Format (PDF). |
|
GSC Open File
4613 (Plot size PDF 2 to 7 MB)
Read me |
1:50K |
1:250K |
| MTF - Magnetic total
field (nT) |
94E:10/11, 7, 6, 3, 2
94D:15 |
4612_09.pdf
(3.2 MB) |
|
CVG -
Calculated magnetic vertical gradient (computed, nT/m) |
94E:10/11, 7, 6, 3, 2
94D:15 |
4612_10.pdf
(3.6 MB) |
|
POT -
Potassium (K, %) |
94E:10/11, 7, 6, 3, 2
94D:15 |
4612_02.pdf
(3.3 MB) |
|
URA -
equivalent Uranium (eU, ppm) |
94E:10/11, 7, 6, 3, 2
94D:15 |
4612_03.pdf
(3.6 MB) |
|
THO - equivalent Thorium (eTh, ppm) |
94E:10/11, 7, 6, 3, 2
94D:15 |
4612_04.pdf
(3.5 MB) |
|
ADRN -
Natural air absorbed dose rate (ADRN, nGy/h) |
94E:10/11, 7, 6, 3, 2
94D:15 |
4612_01.pdf
(3.3 MB) |
|
RUT -
equivalent Uranium/equivalent Thorium (eU/eTh) |
94E:10/11, 7, 6, 3, 2
94D:15 |
4612_05.pdf
(3.7 MB) |
|
RUK - e
quivalent Uranium/Potassium (eU/K, ppm/%) |
94E:10/11, 7, 6, 3, 2
94D:15 |
4612_06.pdf
(3.6MB) |
|
RTK - e
quivalent Thorium/Potassium (eTh/K, ppm/%) |
94E:10/11, 7, 6, 3, 2
94D:15 |
4612_07.pdf
(3.6 MB) |
|
TER - Ternary
radioelement map (K, eU, eTh) |
94E:10/11, 7 ,6, 3, 2
94D:15 |
4612_08.pdf
(3.3 MB) |
| **Also see
Analogue and Digital Products for MapPlace
layer themes and file downloads. |
3. Available only from the Radiation Geophysics Section in Ottawa,
on demand.
| Customized geophysical survey digital data on
CD-ROM in a user-compatible format. |
|
This page was last updated
September 12, 2007. |
