Till
（重定向自Glacial deposit）
![Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as matrix support, is diagnostic of till.](/Images/godic/202501/15/Geschiebemergel4529.JPG")
![Glacial till with tufts of grass](/Images/godic/202501/15/Glacial_till_exposed_in_roadcut-750px4529.jpg")
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Till or glacial till is unsorted glacial sediment.
Till is derived from the erosion and entrainment of material by the moving ice of a glacier. It is deposited some distance down-ice to form terminal, lateral, medial and ground moraines.
Till is classified into primary deposits, laid down directly by glaciers, and secondary deposits, reworked by fluvial transport and other processes.