Pag 1-17 Flashcards
What is exfoliation (onion skin weathering)
When a rock is repeatedly heated and cooled which causes small pieces of the rock surface to fall of
What is freeze thaw weathering
Is when the water fills a crack in a rock and freezes and melts repeatedly which makes the crack wider and eventually the rocks breaks into several pieces
What is biological weathering
When seeds fall into cracks in rocks which grow into trees or plants. The roots force the crack to widen and eventually fall apart.
Burrowing animals can break Dow the rock
What is chemical weathering
When rain which contains acid rots the rock and make it crumble away
Can be seen on grave stones
What is corrosion
Has a sand paper effect
E.g sand in a wave erodes a sea cliff
What is corrosion
Chemicals and salt react with certain minerals in a rock
E.g rainwater dissolves and removes calcium carbonate from limestone
What is hydraulic action
The force and power of waves erode the coast
E.g surfers ride the waves
What is hydraulic pressure
When air is compressed in cracks in a rock when waves crash in to it.
What is attrition
When waves and sea currents move the pieces of broken rock in the water. The pieces collide with each other breaking into smaller Pieces which eventually get so small that they get deposited on the coast
How is the river formed
- The river erodes downwards as rocks are scraped along the channel bed.
- The steep sides are attacked by weathering and loosens the sides.
- because of gravity the loosened material gets washed into the river and washed away
- The result is a steep sided valley that has the shape of a v
What is the source
Where the river starts
What are the spurs
Ridges of land around which a river winds
What are the valley sides
The slopes on either side of a river
What is the channel
The course of a river
What are the river banks
The sides of a river channel
