YehliuTaiwan-HoneycombWeathering 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. YehliuTaiwan-HoneycombWeathering 180px-GeologicalExfoliationOfGraniteRock

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