Geological maps at this scale were usually compiled for the production of "Going" maps, which were needed in situations where off-road, overland routes might have to be undertaken by tanks and heavy vehicles. Prepared by S.O.II (Geology) and G.S.I. (R.E.) H.Q. 21 Army Group. This map was originally held by the Department of Defence, and was acquired by the Laurier Military History Archive (LMH) from the Directorate of History and Heritage, Government of Canada, in the 1990s. Digitization and georeferencing of the map was performed at the University of Waterloo.