A poorly sorted mixture of mud, sand and gravel-sized material deposited directly from glacier ice. The principal types of till are basal, deposited beneath a glacier, and embracing lodgement till (plastered on the bed) and meltout till (released from slow-moving or stagnant ice); and supraglacial meltout till, let down onto the substrate from the glacier surface.

Basal till from the last major glaciation in Britain, c. 18,000 years ago; north shore of Loch Torridon, NW Scotland. Photo M. J. Hambrey.