EROSION and DEPOSITION

Question 1

What are the agents of erosion and deposition?

Answer 1

1) Water (rivers)
2) Sea
3) Moving ice
4) Wind

Question 2

Explain how RIVERS (WATER) causes erosion and deposition

Answer 2

The river follows a path as it flows. This is called the course.

#The river has a STARTING point (source) and a END point (mouth)
# DEPOSITION occurs in the LOWER course where the heavier materials
are deposited (like rocks)

Question 3

Name the 3 courses a river has

Answer 3

1) Upper
2) Middle
3) Lower

Question 4

Explain the UPPER course of a river

Answer 4

• Beginning of the river
• Water flows QUICKLY (lots of energy)
• STEEP slope and NO deposition occur here
• EROSION occurs here that DEEPENS the valley, forming spurs

Question 5

In which part of the river course does NO deposition occur?

Answer 5

Upper course

Question 6

Why does a lot of EROSION take place in the UPPER COURSE?

Answer 6

REASON = River flows QUICKLY (lots of energy)

Question 7

Explain the MIDDLE course of a river course

Answer 7

• WIDE floor
• most EROSION takes place in the width of the river
• water starts to SLOW DOWN
• more water here than in the upper course

Question 8

In which part of the river course does the water flow the SLOWEST?

Answer 8

Lower

Question 9

In which part of the river course is there NO erosion?

Answer 9

lower

Question 10

In which part of the river course is there LOTS of deposition?

Answer 10

lower

Question 11

Explain the Lower course in the river course

Answer 11

• End of water
• River flows very SLOWLY
• Lots of water
• Deposition dominates
• New landforms are formed

Question 12

Why are there new landforms formed in the lower course of the river?

Answer 12

It has the MOST deposition

Question 13

How is a U-Shape VALLEY formed?
U U U U U U U U U U U U U U U U U

Answer 13

> Soil / rocks are eroded by fast running water
Vertical erosion always takes place in the UPPER course of the river (as
the water flows the FASTEST)
this forms a deep valley

Question 14

In which part of the river course does VERTICAL erosion take place and why?

Answer 14

LOCATION = upper course
REASON = fastest water flow

Question 15

What is a RAPID?

Answer 15

River becomes shallower

# Rock is exposed above the flow surface

Question 16

Give one word for when there is a huge bend in a river

Answer 16

Meander

Question 17

How does a meander develop?

Answer 17

• water flow over flat land
• water flows slow on inner bend and EROSION occurs
• water flows slow on inner bend and DEPOSITION occurs
• the deposited material forms part of the FLOODPLAIN
• the OUTER bend of meander continues to erode
• the neck becomes narrower
• later the two OUTER bends meet

Question 18

How does beaches form?

Answer 18

> When DEPOSITION occurs
Weather material are carried by rivers and DEPOSITED into the sea
EROSION occur in the sea
The waves transports material and DEPOSITED in quieter areas
Material is DEPOSITED on the shore when WAVES break
When lots of weather material are accumulated in a place
= this is how a BEACH IS FORMED

(other landforms like spits and barrier islands are also formed due 
 to DEPOSITION)

Question 19

How are U-SHAPED valleys formed through MOVING ICE?

Answer 19

• powerful EROSION action of glaciers
• U = characteristic U-shape with steep straight sides and flat bottom

Question 20

What are moving ice called?

Answer 20

Glaciers

Question 21

EROSION by moving ice (glaciers) are caused by 2 processes, name them

Answer 21

1) Abrasion
2) Plucking

Question 22

Explain how erosion takes place in the ABRASION process

Answer 22

ROCKS in the ice scrape against ROCK on the bedrock

Question 23

Explain how erosion takes places through the PLUCKING process

Answer 23

Pieces of bed rock under the moving ice are PULLED from the surface as the glacier moves

Question 24

What are GLACIAL STRIATIONS?

Answer 24

Scratch / striation marks seen on rocks.
This is where glaciers have scratched lines in the rock.