| The MapPlace - Iron Mask Geophysics (BCMEM
OF 2005-13
/
GSC OF 2817) |
 |
| Details:
Iron Mask Geophysics
covers the 1995
Iron Mask survey represented in Geological
Survey of Canada
Open File 2817. This survey was
published to MapPlace on April 8, 2005. The MapPlace data includes digital
gridded images for 2 magnetic and 7 radiometric parameters for each survey
area. The downloadable files from this website are in georeferenced TIF –
tagged image and PNG formats (UTM NAD 83 and Albers projections) and GRD -
Geosoft gridded data format (UTM NAD 83 only). PDF theme files,
which represents a subset of the geophysical data,
available in
Open File 2006-12:
Integrated Airborne Geophysical, Geology and Mineral Occurrence Data, Iron
Mask Batholith. Geology of the Iron Mask Batholith
is available as
Open File Map
2006-11. See
GeoFile 2006-5
for a review of the regional geological setting, tectonics, geochronology,
geophysics, mineralization and alteration characteristics of the Iron Mask
Batholith.
View
Iron Mask Geophysics Map
Survey Summary:
IRON MASK GEOPHYSICAL SURVEY
BCMEM Open
File 2005-13
/
GSC Open File 2817
Airborne geophysical survey,
Iron Mask Batholith, British Columbia
(Parts of NTS 92I/08NW; 92I/09SW; 92I/10; 92I/15SE)
By
Shives, R.B.K.; Carson, J.M.,
Geological Survey of Canada; 61 pages,
18 maps
Analogue and
digital products include data for seven radiometric and two magnetic
parameters:
| Map Layer
Themes |
Iron Mask
PDF
Themes Files |
| MTF - Magnetic total
field (nT) |
See
Open File
2006-12:
Integrated Airborne Geophysical, Geology and Mineral Occurrence
Data, Iron Mask Batholith. |
|
CVG -
Calculated magnetic vertical gradient (computed, nT/m) |
|
POT -
Potassium (K, %) |
|
URA -
equivalent Uranium (eU, ppm) |
|
THO - equivalent Thorium (eTh, ppm) |
|
ADRN -
Natural air absorbed dose rate (ADRN, nGy/h) |
|
RUT -
equivalent Uranium/equivalent Thorium (eU/eTh) |
|
RUK - equivalent Uranium/Potassium (eU/K, ppm/%) |
|
RTK - equivalent Thorium/Potassium (eTh/K, ppm/%) |
| 1:250K Scale Geology, Mineral Occurrences &
Titles |
| All Themes in one file (11 by 17 images) |
| File
Downloads |
Zip
Files
see Note 1 |
| Georeferenced TIFF files (UTM Zone 10 NAD 83) |
I_tif_Z10.zip
(3.6MB) |
| Georeferenced TIFF files (Albers NAD 83) |
I_tif_AL.zip
(3.6MB) |
| Georeferenced PNG files (UTM Zone 10 NAD 83) |
I_png_Z10.zip
(1.8MB) |
| Georeferenced PNG files (Albers NAD 83) |
I_png_AL.zip
(1.9MB) |
| Original GSC SurView data files for viewing and
printing only (.gri & .grx) |
I_gri.zip
(10.9MB) |
| Original GSC Geosoft gridded data format (.grd),
see Note 2 |
I_grid.zip
(12.5MB) |
Note 1: The TIF and PNG download images include
the geophysical information without topographic base
information.
|
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)
|
|
This page was last updated
September 12, 2007. |
