1. Weathering, Erosion, & Deposition
What are the effects of weathering, erosion, and deposition on the environment in Texas Eco-regions?

2. How does weathering, erosion, & deposition act together in a cycle that changes the Earth’s surface?
Weathering-breaks down the Earth’s surface
Erosion - moves the Earth’s surface (diminishes the surface)
Deposition – drops off sediments to build up the earth’s surface
fc2.galenaparkisd.com

3. Please draw the cycle
Weathering
Erosion
Deposition

4. What is Weathering? Must occur before erosion can happen
The breaking down of rocks into smaller pieces
Must occur before erosion can happen
No movement is involved
Two types: Mechanical & Chemical
Sediments- small/tiny pieces of weathered down rock.

5. What is Physical Weathering?
Physical/Mechanical weathering …
the breaking down of rocks into smaller pieces with out changing what the material
Physical Weathering -- The steep walls here were carved out by moving water
Palo Duro Canyon in the High Plains Eco-Region

6. Enchanted Rock in the Llano Uplift Eco-region
Physical Weathering
1. Animal burrowing
2. Plant Roots
3. Ice Wedging
4. Abrasion
Enchanted Rock in the Llano Uplift Eco-region
5. Exfoliation-warming and cooling
of rocks over time causes rocks
to peel into sheets

7. What is Chemical Weathering?
dissolving and changing the minerals in rocks into new ones.
1. Oxidation-Rusting
2. Plant Acids
3. This cave was formed by slightly acidic water dissolving the limestone (carbonic acids)

8. Chemical Weathering
Natural Bridge Caverns in Texas

9. What is Erosion? Water Wind Water & Gravity Gravity Example
The movement of weathered earth materials by moving water, wind, gravity or ice (glaciers)
Example
Cause of Erosion
Waves eroding the beach and East TX shoreline
Water
Desert Sandstorm in West TX from drought
Wind
Rain causing Mudslide in the Rolling Hills of Central TX
Water & Gravity
Landslide on sides of Plateaus of Central TX
Gravity
Rain carrying soil down a driveway

10. Erosion
Galveston Before and After Hurricane Ike

11. How does removing plants effect the erosion on the left side of the hill?

12. How does keeping plants effect the erosion on the right side of the hill?
Mudslide danger
Loss of topsoil
Clogged storm drains
Flooding problems
Expensive clean up
Eroded or buried
house foundations

13. How vegetation affects erosion..
No/Less vegetation
Vegetation
Soil in place
Less clean up
Minimum erosion
Protection
for house
foundations
Mudslide danger
Loss of topsoil
Clogged storm drains
Flooding problems
Expensive clean up
Eroded or buried
house foundations

14. What is Deposition? Before After
Delta
Mountains
Sand Dunes
Plateau
When eroded sediments are deposited in a new location
Example: delta -- where sediment is deposited where
a river flows into an ocean or lake builds up a landform
Before After

15. Deposition W. Texas Example
Desert winds sculpted these gentle swirls out of the limestone hills in Black Gap Wildlife Management Area, Texas. This remote, 100,000-acre area in West Texas contains some of
the lowest, driest, and
hottest areas in the
Chihuahuan Desert

16. Deposition Deposition area from the Rio Grande River
The Red River carries sediments, and drops some along the way

17. Let’s Practice, write in your S. J
Let’s Practice, write in your S.J. what type of erosion shaped these landforms!
Water, Wind, Gravity, Ice?