Shaping Earths Crust Flashcards
What is denudation
The wearing away of the rocks in the earths surface through weathering and erosion.
What is weathering
The breakdown and decay of rocks that are exposed to weather
Weathering takes place on sit and material that is broken down is not carried away.
What are the two types of weathering
Mechanical weathering and chemical weathering
What is erosion
The breaking down of rocks and the removal of the resulting material. This is done by rivers,the sea, glaciers and the wind.
The material/Rock is then eroded, transported and deposited somewhere else.
Name one type of mechanical weathering
Freeze thaw
What is freeze thaw
When rainfall fills up the cracks in a rock, freezes and expands. This continues and the rock eventually breaks off.
Scree then falls down the mountain.
What is scree
The pile of rocks that break off due to freeze thaw action.
Give two examples of scree in Ireland
Croagh Patrick and the great sugarloaf.
Give an example of chemical weathering
Carbonation
What is carbonation?
Rain falls and takes in carbon dioxide as it passes through the atmosphere.
The carbon dioxide mixes with rainwater and forms a weak carbonic acid.
Limestone contains calcium carbonate. This weak acid reacts with carbon dioxide and slowly dissolves it.
The make up of limestone makes this easier. Limestone is permeable and has vertical cracks (joints) and horizontal bedding planes.
What is a karst landscape
An area of bare limestone exposed to weather
Give two examples of a karst landscape
The burren, and the marble arch
