1. Erosion and Deposition
Forces wear down and build up Earth’s surfaces
Water erosion and a farm field

2. Natural Forces move and deposit sediments
The Grand Canyon was formed by the movement of water
Water flowed over the land and carried away weather rock and soil
This shaped a valley where water flowed creating the canyon

3. Erosion and Deposition
1. Erosion- weathered particles are picked up and moved to a new place
2. Deposition- the part of the erosion process in which sediment in placed (deposited) in a new location

4. Gravity 3. Gravity is the force holding everything down on Earth
This force causes water to move downward (think from the top of a mountain to the bottom)
In the process it carries and deposits sediment in new places

5. 4. Three types of Erosion
Water erosion- rivers, streams carry sediment and deposit sediment at river bottom, floodplain, and mouth of the river
Wind erosion- Strong winds lift tiny particles of dust and carry them long distances
Ice erosion- As ice moves slowly it carries with it rock and soil particles frozen inside of the ice

6. Valleys and Floodplains
As streams flow and carry sediment from the surface of the land they form valleys
Floodplain- area of land on either side of the stream that is underwater when the stream floods

7. Alluvial Fans and Deltas
Alluvial Fan- fan-shaped deposit of sediment at the base of a mountain formed from a stream
Delta- an area of land formed by the buildup of sediment at the end (mouth) of a river

8. Waves and Wind Shape the Land
What natural force created these isolated stone pillars?
The movement of water (waves). The constant action of waves breaking against the cliffs slowing wore the rock cliff away

9. Sand Bars and Barrier Islands
Sandbar- a ridge of sand built up by the action of waves →
Barrier Islands- a sandbar that builds up over time creates a long narrow island parallel to the coast ←

10. Weathering
5. Weathering- the process by which natural forces break down rocks.
2 Types of Weathering:
Mechanical Weathering
Chemical Weathering

11. 6. Mechanical Weathering
Mechanical Weathering- the breaking up of rocks by physical forces. Physical forces split rocks apart but do not change their composition.
Examples of Mechanical Weathering:
Ice Wedging- when water freezes in the cracks and pores of rocks, the force of its expansion is strong enough to split the rocks apart.

12. Mechanical Weathering
Pressure Release- The release of pressure causes the rocks to expand. As the rock expands, cracks form in it leading to exfoliation- when layers or sheets of rock gradually break off.

13. Mechanical Weathering
Plant Root Growth- trees, bushes and other plants may take root in cracks in rocks.
Abrasion- the process of wearing down by friction, the rubbing of one object or surface against another. Water can wear down rocks on riverbeds and along shorelines by abrasion.

14. 7. Chemical Weathering
Chemical Weathering- the breakdown of rocks by chemical reactions that change the rock’s composition.
Examples of Chemical Weathering:
Dissolving- water and acid rain
can cause rocks to start dissolving
Rusting – oxygen in the air and water can combine with iron to cause rusting to occur.