Landforms Resulting from Fluvio Glacial Deposition What happens when the glacier melts?

Landforms Resulting from Fluvio Glacial Deposition By the end of this cycle you will be able to describe the formation of: Outwash plains Eskers Kames Kettleholes

Landforms Resulting from Fluvio Glacial Deposition You will know if you have been successful if you can: answer a past paper question devise a past paper question marking guide mark your partner’s answer

Introduction Fluvio glacial material differs from till in that it is sorted, stratified (layered). Because it was transported by water over longer distances than ice it consists of more rounded deposits of mainly sand and gravel.

Features of fluvio glacial deposition Outwash plains Eskers Kames Kettleholes

Outwash plains Outwash plains are formed in the following way: Meltwater streams rush through the terminal moraine picking up rock pieces. The streams then drop these pieces beyond the terminal moraine as they slow down. The largest pieces are dropped first, for example gravel, followed by smaller ones, for example sand. These areas of sand and gravel, rounded and sorted by meltwater, are called outwash plains.

Braided Streams Form on the outwash plain where channels of meltwater get become clogged by course deposits, encouraging the stream to braid or divide into smaller streams.

Eskers Eskers are formed in the following ways: A meltwater stream follows a tunnel beneath the melting glacier. The stream carries and deposits moraine, filling up the tunnel. When all of the ice melts, a long ridge of moraine is left in the shape of the stream’s tunnel. These long ridges are called eskers.

Kames Kames form in the following way: Some ice is stagnant (doesn’t move) – normally at the edge or detached from the main glacier. Sands and gravel are washed into the crevasses of the stagnant ice. As the ice melts the debris is deposited on the ground. These mounds of debris are called kames.

Kettleholes Kettleholes form in the following way: As the glacier retreats it may leave large blocks of buried ice. This ice slowly thaws over time and the covering gravel collapses leaving a depression. These depressions are called kettle holes. If the depressions are deep enough to tap the water table a kettle hole lake forms.