Weathering, Erosion, and Deposition

Jared RhinehartMs. Pilcher

6A

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Process of WeatheringOne earth process that breaks down rocks into smaller pieces

is called weathering. Over time, rocks crack, crumble, and are broken

apart by water and wind. Drops of water on a rock may repeatedly

freeze and melt, causing the rock to crack. Water may react with

some of the chemicals in a rock and cause part of the rock to break down.

Rocks sometimes fall from higher places, breaking as they fall.

Small ani- mals and the roots of plants also contribute to the

weathering of rock when they burrow into the ground. Weathering forms sediments

that can be moved by wind and water.

Process of ErosionThe movement of sediments from one place to

another by water, wind, or ice is called erosion. When water erodes

the earth’s surface, it cuts into the ground, forming

surface channels. These channels can range from tiny depressions in

the earth to huge canyons, such as the Grand Canyon. Slow and steady

water erosion over long periods of time has created valuable

features of the earth’s landscape such as lakes, rivers, hills, canyons,

and fertile plains.

Process of DepositionWhen erosion carries sediments from one place to another, the sediments are left, or deposited somewhere else. This earth process is called deposition.It occurs when pieces of rock or soil settle out of flowing water or wind as they slow down. The processes of erosion and deposition are closely related because erosion moves the sediments that are eventually deposited. A delta at the mouth of a river is an example of a landform formed by deposition.

Different Types Of Erosion

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Water ErosionWater erosion starts from the chemicals in the water, and the force of the flow in the river. There are many chemicals in a river, and those chemicals can break down certain rocks, such as limestone or chalk. This eroded rock is carried through the river. Sometimes, a crack develops in the rock. When the flowing river forces against the crack, the rock can break, and be carried down the river again.

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Wind ErosionWind erosion may be small where you live, but can take quite a charge on areas of the world covered in desert. Wind erosion is when light objects such as rocks and pebbles are carried by the wind and can hit landforms, eroding materials off them, that are carried off in the wind.

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Glacier ErosionIce erosion, comes mostly in the form of glacier erosion. Glaciers are giant bodies of ice that can pick up huge pieces of rocks, some even as big as houses. A combination of the water, ice, and picked up sediment, create a powerful eroding charge.

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Different Types Of Weathering

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Mechanical WeatheringMechanical weathering takes place when rocks are broken down without any change in the chemical nature of the rocks. The rocks are torn apart by physical force, rather than chemical breakdown. The forces that break rocks down can be a large amount, and including such things as pent up energy. When great amounts of pressure build up, the results can be Mechanical Weathering.

Chemical WeatheringChemical weathering takes place in almost all types of rocks. Smaller rocks are more susceptible however, because they have a greater amount of surface area. Chemical reactions break down the bonds holding the rocks together, causing them to fall apart, forming smaller and smaller pieces. Chemical weathering is much more common in locations where there is a lot of water. This is because water is important to many of the chemical reactions that can take place. Warmer temperatures are also more friendly to chemical weathering. The most common types of chemical weathering are oxidation, hydrolysis and carbonation.

Biological WeatheringBiological weathering would include the effect of animals and plants on the landscape. This is more than roots digging in and wedging rocks. Biological weathering is the actual molecular breakdown of minerals. There are things called lichens (combinations of fungi and algae) which live on rocks. Lichens slowly eat away at the surface of rocks. The amount of biological activity that breaks down minerals depends on how much life is in that area. You might find more activities like lichens near oceans where the air is humid and cooler.

Linking Siteshttp://www.geography4kids.com/files/land_erosion.html

http://www.kidsgeo.com/geology-for-kids/0067-chemical-weathering.php

http://teacher.scholastic.com/dirt/erosion/whateros.htm