Unit 4: Lesson 2 Erosion and Deposition

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

What Caused This? http://commons.wikimedia.org/wiki/File:Water_erosion_below_Hay_Bluff_-_geograph.org.uk_-_1074175.jpg http://commons.wikimedia.org/wiki/File:Wind_erosion_Seminole_Canyon.JPG http://commons.wikimedia.org/wiki/File:Baventian_Clay_Beds_-_geograph.org.uk_-_1776748.jpg

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

Wind Erosion: Wind – wears away rocks and is responsible for the creation of deserts Small fragments Loose material Dry climate http://commons.wikimedia.org/wiki/File:Wind_Erosion_Features_in_Wadi_Al-Hitan.jpg

Water Erosion: Water – most influential force in erosion Transports large objects with fast moving streams Wears away rocks forming: rivers lakes oceans http://commons.wikimedia.org/wiki/File:Water_erosion_below_Scarsoch_Bheag_-_geograph.org.uk_-_1367808.jpg

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 http://commons.wikimedia.org/wiki/File:Wave_Erosion,_Downpatrick_Head_-_geograph.org.uk_-_369272.jpg

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 http://www.onegeology.org/eXtra/kids/earthProcesses/massMovements.html

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 http://commons.wikimedia.org/wiki/File:U-shaped_valley_at_the_head_of_Leh_valley,_Ladakh_(2).JPG

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

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. http://commons.wikimedia.org/wiki/File:Desert_Chihuahuan_Big_Bend.JPG

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. http://commons.wikimedia.org/wiki/File:Enchanted_Rock,_stream.jpg

Deposition - Ice When the glacial ice melts, materials that were carried are deposited http://commons.wikimedia.org/wiki/File:Cavell_Glacier_with_Crevices_and_Annual_Rings.jpg

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.