Contained within the 3rd Edition (1957) of the Atlas of Canada is a map that shows the locations of glacial materials, circa mid-1950s. The extents of existing glaciers and ice caps are shown. The direction of ice movement is illustrated by denoting the trends of drumlins (elongated or oval hills of glacial drift), drumlinoid ridges, flutings, glacial striae, grooves and roche-moutonee (rounded glacially shaped rock) as well as the direction of valley glacier movements. Areas of extinct glacial lakes are shown with glacial spillways which are outlets of these extinct glacial lakes. Deposits of ground moraine, end moraine and undifferentiated glacial drift are shown along with trends of minor moraine. Moraine is generally defined as till, gravel, sand, clay etc. that has been carried and deposited by a glacier. Also shown are the locations of eskers, which are irregularly stratified, winding ridges of sand, gravel and boulders deposited by fast flowing glacial streams that may run through, over or under ice.