Glacial till is an unsorted, unstratified mixture of sediments ranging from clay to boulders, deposited directly by glacial ice. It is significant in understanding past glacial environments, the dynamics of ice movement, and the geological history of glaciated regions. Till forms the basis for many glacial landforms, including moraines and drumlins.
Reference: Dreimanis, A. (1976). Tills: Their Genetic Terminology and Classification. Geological Society of America Bulletin.