What are the effects of weathering, erosion, and

deposition on the environment in Texas

Eco-regions?

Weathering, Erosion, & Weathering, Erosion, & DepositionDeposition

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

How does weathering, How does weathering, erosion, & deposition act erosion, & deposition act together in a cycle that together in a cycle that

changes the Earth’s changes the Earth’s surface?surface?

Please draw the cyclePlease draw the cycle

Weathering

ErosionDeposition

Must occur before erosion can happen

No movement is involvedTwo types: Mechanical & Chemical Sediments- small/tiny pieces of

weathered down rock.

The breaking down of rocks into smaller pieces

What is Weathering?What is 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

What is Physical What is Physical Weathering?Weathering?

Enchanted Rock in the Llano Uplift Eco-region

5. Exfoliation-warming and cooling of rocks over time causes rocks to peel into sheets

Physical WeatheringPhysical Weathering1. Animal burrowing2. Plant Roots3. Ice Wedging4. Abrasion

3. This cave was formed by slightly acidic water

dissolving the limestone (carbonic acids)

Chemical weathering … dissolving and changing the minerals in rocks into new ones.1. Oxidation-Rusting 2. Plant Acids

What is Chemical What is Chemical Weathering?Weathering?

Natural Bridge Caverns in Texas

Chemical WeatheringChemical Weathering

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

Water & Gravity

The movement of weathered earth materials by moving water, wind, gravity or ice (glaciers)

What is Erosion?What is Erosion?

ErosionErosion Galveston Before and After Hurricane Ike

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

• Mudslide danger

• Loss of topsoil• Clogged storm drains• Flooding problems• Expensive clean up

• Eroded or buried house foundations

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

• Soil in place• Less clean up

• Minimum erosion• Protection for house foundations

How vegetation affects erosion..

No/Less vegetation Vegetation

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

What is Deposition?What is Deposition?1.1.DeltaDelta2.2.MountainsMountains3.3.Sand DunesSand Dunes4.4.PlateauPlateau

W. Texas ExampleDesert 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

DepositionDeposition

Deposition area from the Rio Grande River

The Red River carries sediments, and drops some

along the way

DepositionDeposition

Let’s Practice, write in your S.J. what type of erosion shaped these landforms!

Water, Wind, Gravity, Ice?