Download Erosion - Gorzycki Middle School

Weathering
The process of breaking down of rocks into
smaller and smaller pieces of rock. These
small pieces are known as sediment.
Sediment breaks down further and becomes
soil.
180px-GeologicalExfoliationOfGraniteRock
YehliuTaiwan-HoneycombWeathering
Types of Weathering
Mechanical/ Physical Weathering
Chemical Weathering
Types of Mechanical Weathering
Ice Wedging- Water in the cracks of rocks
freeze
Abrasion- Particles of sand are carried by the
wind and water
Plant Action – roots from plants grow in the
cracks of rocks
Release pressure – when pressure is removed
from rocks
Chemical Weathering
The process in which the chemical makeup
of a rock is changed by a chemical reaction.
http://en.wikipedia.org/wiki/Weathering#Chemical_weathering
Types of Chemical Weathering
Oxidation – a chemical
change that occurs when
oxygen and iron form.
Acids – natural acids
break down rock.
http://en.wikipedia.org/wiki/Stalagmite
Erosion
Erosion takes rocks and other particles from
one location and puts them in another.
Weathering is breaking up rocks erosion is
carrying them away.
The Agents of Erosion
Wind
Water
Glaciers
Gravity / Mass Movement
Wind Erosion
Wind can carry sand, silt, and clay from one
place and deposit it in another.
This type of erosion is most frequent in dry
areas with little or no vegetation.
Wind Erosion
http://upload.wikimedia.org/wikipedia/en/1/15/Mesquite_Sand_Dunes.JPG
Water Erosion
The most important agent of erosion is running water.
 Water runs down hill and form a gully by taking away
sediment.
Water continues to flow in the gully and eventually forming
a valley.
Water can cause erosion of the shore line can be from
waves in the ocean.
Water Erosion
http://en.wikipedia.org/wiki/Image:Gully_ElPasoCounty_CO_USA.jpg
Water Erosion
http://en.wikipedia.org/wiki/Image:Wavecut_platform_southerndown_pano.jpg
Glaciers Erosion
Glacier Erosion is sometimes referred to as Ice Erosion
Glaciers move slowly across land picking up large rocks
and even larger boulders.
Glaciers can cause deep valleys to form as they move
across the land.
Glaciers Erosion
http://en.wikipedia.org/wiki/Image:Glacier_mouth.jpg
Gravity/Mass Movement Erosion
Gravity is the force behind Water and Glacier Erosion
Gravity alone can cause Erosion
Gravity/Mass Movement Erosion
http://en.wikipedia.org/wiki/Erosion#Gravity_erosion
Types of Gravity/Mass
Movement Erosion
Slump
Creep
Rockfalls
Rockslides
Mudflows
Landslides
Slump
A slump occurs when a mass of land slips and moves down a
slope.
A slump occurs when the slope becomes too steep and the
material under it can not support the ground above it.
http://geology.about.com/library/bl/images/blslump.htm
http://geology.about.com/library/bl/images/blslump.htm
Creep
Sediment slowly moves down hill.
Leaning trees and fence post are clues that
creeping is occurring
Rockfalls
Occur when parts of a rock break off a tumble through the air.
http://www.seismo.ethz.ch/hazard/risk/PaleoSeis/rockfalls2.htm
Rockslides
Large and small rock slide down a slope.
http://www.grisda.org/origins/11090.htm
Mudflows
Happen after heavy rains.
More likely to occur when there is a lack of vegetation.
Gravity pulls on the heavy water saturated sediment and
causes it to flow down hill.
http://en.wikipedia.org/wiki/Image:Mudflow_mailboxes.jpg
Landslides
A movement of land down a slope.
http://www.signonsandiego.com/news/state/20050601-1811-wst-lagunalandslide.html
Deposition
Process by which sediments, soil and rocks
are added to a landform or land mass (the
end of erosion).
http://education.usgs.gov/lessons/schoolyard/RockSedimentary.html