Surficial geology index map

This entry provides access to surficial geology maps that have been published by the Geological survey of Canada. Two series of maps are available: "A Series" maps, published from 1909 to 2010 and "Canadian Geoscience Maps", published since 2010.

Three types of CGM-series maps are available:

1)Surficial Geology: based on expert-knowledge full air photo interpretation (may include interpretive satellite imagery, Digital Elevation Models (DEM)), incorporating field data and ground truthing resulting from extensive, systematic fieldwork across the entire map area. Air photo interpretation includes map unit/deposit genesis, texture, thickness, structure, morphology, depositional or erosional environment, ice flow or meltwater direction, age/cross-cutting relationships, landscape evolution and associated geological features, complemented by additional overlay modifiers, points and linear features, selected from over 275 different geological elements in the Surficial Data Model. Wherever possible, legacy data is also added to the map.

2)Reconnaissance Surficial Geology: based on expert-knowledge full air photo interpretation (may include interpretive satellite imagery, DEMs), with limited or no fieldwork. Air photo interpretation includes map unit/deposit genesis, texture, thickness, structure, morphology, depositional or erosional environment, ice flow or meltwater direction, age/cross-cutting relationships, landscape evolution and associated geological features, complemented by additional overlay modifiers, points and linear features, selected from over 275 different geological elements in the Surficial Data Model. Wherever possible, legacy data is also added to the map.

3)Predictive Surficial Geology: derived from one or more methods of remote predictive mapping (RPM) using different satellite imagery, spectral characteristics of vegetation and surface moisture, machine processing, algorithms etc., DEMs, where raster data are converted to vector, with some expert-knowledge air photo interpretation (training areas or post-verification areas), varying degrees of non-systematic fieldwork, and the addition of any legacy data available.

Each map is based on a version of the Geological Survey of Canada's Surficial Data Model (https://doi.org/10.4095/315021), thus providing an easily accessible national surficial geological framework and context in a standardized format to all users.

"A series" maps were introduced in 1909 and replaced by CGM maps in 2010. The symbols and vocabulary used on those maps was not as standardized as they are in the CGM maps. Some "A series" maps were converted into, or redone, as CGM maps, Both versions are available whenever that is the case.

In addition to CGM and "A series" maps, some surficial geology maps are published in the Open File series. Those maps are not displayed in this entry, but can be found and accessed using the NRCan publications website, GEOSCAN:(https://geoscan.nrcan.gc.ca).