1. Unit 4: Lesson 2 Erosion and Deposition

2. TEKS:
Analyze the effects of weathering, erosion, and deposition on the environment in ecoregions of Texas

3. What Caused This?

4. Erosion – moving of rock material from one place to a new location
What is Erosion?
Erosion – moving of rock material from one place to a new location
Three processes must take place:
detachment of particles
lifting them
transporting them

5. Wind Erosion:
Wind – wears away rocks and is responsible for the creation of deserts
Small fragments
Loose material
Dry climate

6. Water Erosion: Water – most influential force in erosion
Transports large objects with fast moving streams
Wears away rocks forming:
rivers
lakes
oceans

7. Wave Erosion:
Waves – relentless pounding of the water erode the rock off the coastline.
softer/weaker rock first
harder/more resistant left behind
Can take over 100s of years

8. Gravitational Erosion:
Mass Movement – downward movement of rock and sediments, due to gravity
move material from higher  to lower  elevation
Occurs continuously on all slopes
Can cause massive landslides

9. Glacial Erosion:
Ice – moves and carries rocks, grinding the rocks beneath the glacier
Plucking
Picking up pieces of rock and carrying them
Abrade (abrasion)
scraping along rock under the glacier

10. What is Deposition?
Deposition – laying down of sediment that has been transported
Large rocks, hills, vegetation, etc. slow down erosion process and moving particles settle on a surface

11. Deposition - Wind Transportation of particles in wind:
Material is deposited when the wind changes direction or loses its strength.
Fine particles are carried while heavy material is blown along the ground.

12. Deposition - Water
As the speed of the water decreases, the water's ability to carry sediment also decreases.
Running water enters a large, fairly still body of water and its speed decreases
Deposited in streams, rivers, and oceans:
Largest particles are deposited near the shore.
Increasingly smaller particles settle out farther from the shore where the water is calmer.

13. Deposition - Ice
When the glacial ice melts, materials that were carried are deposited

14. What’s the Difference?
WEATHERING – Think of weather wearing rock down.
EROSION – Think of a road and traveling.
DEPOSITION – Think of depositing money into a bank.