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Definition:
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An unsorted and unstratified accumulation of glacial sediment, deposited directly by glacier ice. Till is a heterogeneous mixture of different sized material deposited by moving ice (lodgement till) or by the melting in-place of stagnant ice (ablation till). After deposition, some tills are reworked by water. 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.
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