Chapter 7 Vocabulary

Front 1

Ice age

Back 1

A period if time when much of Earth's land is covered in glaciers. Sheets of ice that were thousands of meters thick shaped places like the Alps, Cape Cod, nad Yosemite Valley

Front 2

Glacier

Back 2

A thick ice mass that forms over hundreds or thousands of years. Today it still overs nearly 10 percent of Earth's land area

Front 3

Snowline

Back 3

The lowest elevation in a particular area that remains covered in snow all year. At the poles it occurs at sea level.

Front 4

Valley glacier

Back 4

Ice masses that slowly advance down valley that were orginally occupied by streams. It also flows between steep rock walls from a place near the top of the mountain valley

Front 5

Ice sheet

Back 5

Enormous ice masses that flow in and directions form one or more centers and cover everything but the highest land

Front 6

Glacial trough

Back 6

The once narrow V-Shaped valley is changed into a v-Shaped glacial trough

Front 7

Till

Back 7

Material deposited directly by the glaciers. It's deposited as the glacier melts and drops its load of rock debris.

Front 8

Stratified drift

Back 8

Sediment laid down by glacial meltwater. It contains particles that are sorted according to size and weight of the debris often consits of sand and gravel, because the meltwater cannot move large boulder sand finer sediments remain suspended and are carried far from the glacier.

Front 9

Moraine

Back 9

When glaciers melt, they leave layers of ridges of till. These widespread glacial features come in several varieties

Front 10

Alluvial fan

Back 10

Fan-shaped deposit of sediment formed when a stream's slope is abruptly reduced

Front 11

Playa lake

Back 11

A flat area on the floor of an undrainage desert basin that fills and becomes a lake after heavy rain

Front 12

Delation

Back 12

The lifting and removal of loose particles such as clay and silt

Front 13

Desert pavement

Back 13

A layer of coarse pebbles and gravel created when wind removed the finer material

Front 14

Loess

Back 14

Wind blown silt that blankets the landscape

Front 15

Dune

Back 15

Unlike deposits of loess, which form blanket-like layers over broad areas, winds commonly deposit sand in mounds or ridges