Glaciers are effective agents for transporting enormous quantities of rock debris. The load consists of rock debris ranging in size from fine particles to huge boulders, which are distributed more or less evenly throughout the whole mass of the glacier. A large part of the load of valley glaciers is contributed by:
– erosion of rocks by the glacier; ;
– weathering and mass-wasting processes which operate quite effectively in mountain slopes, above the level of the glacier ice:
– plucking of the unconsolidated materials over which the glacier moves.
Much of the load of the valley glaciers is carried on the glacier- surface and on its sides.
The load is carried frozen within the ice, however, larger and heavier rock-fragments sink down through the ice and accumulate at the bottom of the glacier, which is responsible for the rasping and abrasive action of the glacier.
The load carried by the glaciers is known as Glacial-drift, which is unsorted and unstrati-fied.