| A | B |
|---|
| alluvial fan | a fan-shaped deposit of sediment formed when a stream’s slope is abruptly reduced |
| deflation | the lifting and removal of loose material by wind |
| desert pavement | a layer of coarse pebbles and gravel created when wind removed the finer material |
| dune | a hill or ridge of wind-deposited sand |
| glacier | a thick mass of ice originating on land from the compaction and recrystallization of snow that shows evidence of past or present flow |
| ice age | a period of time when much of Earth’s land is covered by glaciers |
| loess | deposits of windblown silt, lacking visible layers, generally light yellow, and capable of maintaining a nearly vertical cliff |
| moraine | a ridge of unsorted sediment left by a glacier |
| playa lake | a flat area on the floor of an undrained desert basin (playa that fills and becomes a lake after heavy rain) |
| snowline | lowest elevation in a particular area that remains covered in snow all year |
| till | sediment of different sizes deposited directly by a glacier |
| valley glacier | a glacier confined to a mountain valley, which in most instances had previously been a stream valley; also known as an alpine glacier |
| cirque | an amphitheater-shaped basin at the head of a glaciated valley produced by frost wedging and plucking |
| continental glacier | a very large, thick mass of glacial ice that covers a large region and flows outward in all directions from one or more accumulation centers; also called a continental ice sheet |
| crevasse | a deep crack in the brittle surface of a glacier |
| drumlin | a streamlined asymmetrical hill composed of glacial till; The steep side of the hill faces the direction from which the ice advanced. |
| esker | sinuous ridge composed largely of sand and gravel deposited by a stream flowing in a tunnel beneath a glacier near its terminus |
| glacial erratic | an ice-transported boulder that was not derived from bedrock near its present site |
| kettle | depression created when a block of ice became lodged in glacial deposits and subsequently melted |
| outwash plain | a relatively flat, gently sloping plain consisting of materials deposited by meltwater streams in front of the margin of an ice sheet |
| firn | coarse grains of ice resulting from recrystallization of compressed snow |
| ventifact | a cobble or pebble polished and shaped by the sandblasting effect of wind |
