Processes that Shape the Earth

Rocks, Weathering, and Erosion

Ms. AjaMs. Aja

55thth Grade Grade

Rocks

• Solid earth material• Make up the crust of the Earth• Mixture of one or more minerals• Range in size from giant mountains to grains

of sand• Can be smooth or rough, shiny or dull, one

color or many colors• Three main types: 1. sedimentary 2. igneous 3. metamorphic

Minerals http://geology.csupomona.edu/alert/mineral/minerals.htm

• A solid material that is formed by nature in or on Earth’s crust

• A material that has a crystal form• A material that is not formed by a living thing• A material that has its own set of properties• http://www.theimage.com/mineral/minerals1.html

Igneous Rocks http://sln.fi.edu/fellows/payton/rocks/create/igneous.htm

• Form when magma (hot liquid rock) cools and hardens

• “Fire formed” rocks• Common near volcanoes http://volcano.oregonstate.edu/

• http://geology.about.com/cs/basics_roxmin/a/aa011804a.htm• http://geology.about.com/od/rocks/ig/igrockindex/

Metamorphic Rocks

http://sln.fi.edu/fellows/payton/rocks/create/metamorph.htm

• Form when underground rocks are changed due to high pressure

• “Changed” rocks• Common in mountains

Sedimentary Rocks http://sln.fi.edu/fellows/payton/rocks/create/sediment.htm

• Form when layers of rock particles get pressed together at or near Earth's surface

• “Layered” rocks• May contain fossils• Common near bodies of water or where water existed

in the past

Physical Weathering http://geomaps.wr.usgs.gov/parks/project/index.html

1. Wind

2. Rain3. Ice

4. Plant roots

Chemical Weathering

• Carbonation – CO2 & water break down lime stone

• Solution – minerals in rocks dissolve in water

• Oxidation – oxygen & water & minerals react and weaken the rock

• Lichens

Erosion

• Erosion is the movement of sediments from one place to another.

• Water is the primary agent of erosion, though wind and glacier ice also contribute .

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Rock Cyclehttp://www.classzone.com/books/earth_science/terc/content/investigations/es0602/es0602page02.cfm