NT GoMap
Detailed Reference Report
Cover Information
Megatype Government Scientific Publication; NTGO Publication
Type EGS Open Report
Number 2001-003
Filing/Pub Date 2001-11-01
Release Date
Title Slave Magnetics Compilation (SMAC): A digital image compilation of public total field magnetic data as filed in accordance to the Canada Mining Regulations, NWT and NU
Author Armstrong JP, Kenny G
Territory NWT
Bounding Box
Latitude min: 62
max: 68
Longitude min: -118
max: -108
Geographic Area Slave Craton; Northwest Territories; Nunavut
Period of Work From To
Target(s) of Exploration None/Any
Publisher Dept. Indian Affairs and Northern Development, NWT Geology Division
Availablity Distributed by NTGO
Medium Digital File(s) 8 CD's up to 700 MB each. 4585 MB in 1144 files. PDF, ESRI shapefile, Access or dBase, georeferenced TIF.
Miscellaneous Exploration
No Digital Data
Comment The purpose of SMAC is to create a GIS compatible digital image database of high resolution total field magnetic airborne geophysical surveys. Much of this data is contained as hard-copy (paper) maps within Assessment Reports submitted pursuant to the Canada Mining Regulations, some of the data has been filed in a digital form. For the initial phase total field magnetics data was accessed from public assessment filings for the period 1990-1998 that cover the Slave craton from the Arctic coast to Great Slave Lake. Digital data, where available, was reprocessed and gridded with Geosoft Montaj and 200 dpi geotiff images generated. Paper maps were scanned with an E-size drum scanner. The resulting TIFF image (400 dpi, CCITT Group 4 compression) was geo-referenced (indexed) with CAD Overlay. Colour maps were scanned with an indexed colour look up table comprised of 32 colours. Colour TIFF images are saved with Macpaint packbit compression. Images were cropped to only include the actual survey area. Multiple images from the same survey were merged together to form one image. All tiff files are accompanied by an associated world file (*.tfw). A polygon was created outlining the area for each survey. An accompanying table houses the following information: assessment report, property operator, geophysical contractor, survey platform (heli/fixed wing), line spacing, bird height, date of survey, digital data (yes/no), etc... The table is constructed in such a form to enable linkage between the individual images and the table.


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