Moving Rock
Weathering & Erosion
Weathering
 Processes
that change the
characteristics of rocks on the Earth’s
surface
 Must occur BEFORE erosion can
happen
 No movement is involved
 Occurs when rocks are exposed to
water, air or plants
Mechanical Weathering
 BREAKS
rocks into different shapes
and smaller sizes
 Jagged rocks usually become smooth
Abrasion
Breaking, grinding,
wearing away of
rock
 Caused by wind
and water

http://richmond.k12.va.us/schools/thirtee
nacres/images/rockpic5.jpg
Frost Action or Ice Wedging

Freezing water in
cracks expands
and breaks rocks
http://www.bearmountainzoo.org/es12.jpg
Plate Movement

The moving and
sliding of tectonic
plates wear away
rocks as they slide
past each other
http://piru.alexandria.ucsb.edu/~tierne
y/trs0demo/trs-0_files/geosystems1208%5B1%5D.jpg
Exfoliation / Temperature Change

Warming and
cooling of rock
causes top layers
to break off in
sheets
http://uregina.ca/~sauchyn/geog323/279.j
pg
Close to Home – Enchanted Rock
http://geology.uprm.edu/Morelock/ima
ges/965ERdome.jpg
http://www.answers.com
Plants and Animals

Wedging of roots
and burrowing of
animals wears
away rock
http://www.geol.lsu.edu/Faculty/Ferrell/clas
s/ClarkCreek/weathering_img2.gif
Close to Home – Texas Hill Country
http://www.texasep.org/cpft/lugc.html
Chemical Weathering
 Process
by which rocks are
decomposed, dissolved or loosened
by chemical processes to form
sediment
http://academic.brooklyn.cuny.edu/geology/leveson/co
re/topics/weathering/picture_gallery/display/graphics/y
orkshire_72.gif
http://cse.cosm.sc.edu/erth_sci/Soil/ss12_2.jpg
http://www.geol.lsu.edu/Faculty/Ferrell/class/ClarkCreek/weatheri
ng_img3.gif
Erosion
 The
removal of weathered rocks by
the action of:
– Water
– Wind
– Ice
– Gravity
Water Erosion
http://www.greenpeace.org/raw/image_full/russ
ia/en/photosvideos/photos/trees-can-stopwater-erosion
Close to Home – Canyon Lake
After the
Flood
http://www.cceo.org/gorgesite/index.
htm
Close to Home – Beach Erosion
Three feet a year in some places!
http://tamusystem.tamu.edu/systemwide/06/01/photos/erosion.jpg
Wind Erosion
http://www.helsinki.fi/~jhyvonen/PB/M/wind%20erosion%202pp.JPG
http://www.uwsp.edu/geo/faculty/ritter/geog101/te
xtbook/images/lithosphere/eolian/wind_erosion_
New_Mexico_p0772931600_NRCS.jpg
http://www.ram.org/pictures/sights/oahu_san_diego/cabrillo_e
rosion_1.gif
Ice Erosion
http://www.swisseduc.ch/stromboli/etna/etna00/etna0002phot
ovideo/icons/f20.jpg
http://www.sciencedaily.com/images/200
5/12/051211220547.jpg
http://chandi.smugmug.com/photos/2
6411520-L.jpg
Gravity
http://www.mariposacounty.org/fire/images/images%20200
6/web%20140%20rock%20slide%207-4-06%20004.jpg
http://people.hofstra.edu/
faculty/j_b_bennington/n
y_geology/adirondacks/a
dirondacksImages/10.jpg