Moving RockMoving Rock

Weathering & ErosionWeathering & Erosion

Grade 8; GLE 14http://www.science-class.net/Geology/weathering_erosion.htm

WeatheringWeathering

Processes that change the Processes that change the characteristics of rocks on the characteristics of rocks on the Earth’s surface Earth’s surface

Must occur BEFORE erosion can Must occur BEFORE erosion can happenhappen

No movement is involvedNo movement is involved Occurs when rocks are exposed to Occurs when rocks are exposed to

water, air or plantswater, air or plants

Mechanical Weathering Mechanical Weathering

BREAKS rocks into different shapes BREAKS rocks into different shapes and smaller sizesand smaller sizes

Jagged rocks usually become smoothJagged rocks usually become smooth

AbrasionAbrasion

Breaking, grinding, Breaking, grinding, wearing away of wearing away of rockrock

Caused by wind Caused by wind and waterand water

http://richmond.k12.va.us/schools/thirteenacres/images/rockpic5.jpg

Frost Action or Ice WedgingFrost Action or Ice Wedging

Freezing water in Freezing water in cracks expands cracks expands and breaks rocksand breaks rocks

http://www.bearmountainzoo.org/es12.jpg

Plate MovementPlate Movement

The moving and The moving and sliding of tectonic sliding of tectonic plates wear away plates wear away rocks as they slide rocks as they slide past each otherpast each other

http://piru.alexandria.ucsb.edu/~tierney/trs0demo/trs-0_files/geosystems12-08%5B1%5D.jpg

Exfoliation / Temperature ChangeExfoliation / Temperature Change

Warming and Warming and cooling of rock cooling of rock causes top layers causes top layers to break off in to break off in sheetssheets

http://uregina.ca/~sauchyn/geog323/279.jpg

Close to Home – Enchanted RockClose to Home – Enchanted Rock

http://www.answers.com

http://geology.uprm.edu/Morelock/images/965ERdome.jpg

Plants and AnimalsPlants and Animals

Wedging of roots Wedging of roots and burrowing of and burrowing of animals wears animals wears away rockaway rock

http://www.geol.lsu.edu/Faculty/Ferrell/class/ClarkCreek/weathering_img2.gif

Close to Home – Texas Hill CountryClose to Home – Texas Hill Country

http://www.texasep.org/cpft/lugc.html

Chemical WeatheringChemical Weathering

Process by which rocks are Process by which rocks are decomposed, dissolved or loosened decomposed, dissolved or loosened by chemical processes to form by chemical processes to form sedimentsediment

http://academic.brooklyn.cuny.edu/geology/leveson/core/topics/weathering/picture_gallery/display/graphics/yorkshire_72.gif

http://cse.cosm.sc.edu/erth_sci/Soil/ss12_2.jpg

http://www.geol.lsu.edu/Faculty/Ferrell/class/ClarkCreek/weathering_img3.gif

ErosionErosion

The removal of weathered rocks by The removal of weathered rocks by the action of:the action of:– Water Water – WindWind– IceIce– Gravity Gravity

Water Erosion Water Erosion

http://www.greenpeace.org/raw/image_full/russia/en/photosvideos/photos/trees-can-stop-water-erosion

Close to Home – Canyon LakeClose to Home – Canyon Lake

http://www.cceo.org/gorgesite/index.htm

After the Flood

Close to Home – Beach Erosion Close to Home – Beach Erosion

Three feet a year in some places!http://tamusystem.tamu.edu/systemwide/06/01/photos/erosion.jpg

Wind Erosion Wind Erosion

http://www.helsinki.fi/~jhyvonen/PB/M/wind%20erosion%202-pp.JPG

http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/images/lithosphere/eolian/wind_erosion_New_Mexico_p0772931600_NRCS.jpg

http://www.ram.org/pictures/sights/oahu_san_diego/cabrillo_erosion_1.gif

Ice ErosionIce Erosion

http://www.swisseduc.ch/stromboli/etna/etna00/etna0002photovideo/icons/f20.jpg

http://www.sciencedaily.com/images/2005/12/051211220547.jpg

http://chandi.smugmug.com/photos/26411520-L.jpg

GravityGravity

http://www.mariposacounty.org/fire/images/images%202006/web%20140%20rock%20slide%207-4-06%20004.jpg

http://people.hofstra.edu/faculty/j_b_bennington/ny_geology/adirondacks/adirondacks-Images/10.jpg