the furthest reach of the glacier, as meltwater streams spread material out forming a broad
plain called anoutwash plain(Figure10.44).
Figure 10.44: Stratified drift carried by meltwater spreads out to form an outwash plain just
beyond the furthest reaches of the glacial ice. ( 25 )
If an isolated block of ice remains behind as the glacier retreats, it may be surrounded
and eventually covered over by these layers of sediment. In many years time, as the ice
melts, it fills the depression with water, forming small circular lakes calledkettle lakes
(Figure10.45). These small lakes are common in the areas where glaciers made their
farthest advances.
Figure 10.45: Small, circular lakes are common in areas of glacial outwash. They form from
blocks of ice left behind as the glacier retreats. ( 21 )
Several types of stratified deposits form in glacial regions but are not formed directly by the
ice. In glaciated areas, lakes are covered by ice in the winter. During the winter months,
darker, fine grained clays sink to the bottom of the quiet waters in the lake. In the spring,