Download Weathering, erosion, fossils and the rock cycle.

By Michael Nau and Elizabeth Dorsey
Weathering vs. Erosion
Erosion involves movement and
weathering does not.
 Weathering is the main agent in erosion.

http://www.nature.nps.gov/geology/usgsnp
s/misc/gweaero.html
Weathering
CHEMICAL: involves a chemical change
in some of the minerals in the rock
 PHYSICAL: when the rock physically
brakes down
 Weathering makes sediment (fragments
of material) which is moved by
deposition (wind, water and ice)

http://www.nature.nps.gov/geology/usgsnp
s/misc/gweaero.html
Erosion
When forces of nature move soil and
rock
 SHEET EROSION: when rain washes
away top soil on sloped land. Gravity
(the force that pulls stuff down) is the
force that makes eroded material slide
down hill
 Erosion from the Colorado River formed
the Grand Cannyon.

http://www.watersheds.org/earth/erosion.ht
m
Rock Cycle
ROCK CYCLE: a model of the
formation, breakdown and reformation of
rocks
 Igneous rocks form by cooling magma
 Metamorphic rocks form from heat and
pressure
 Sedimentary rocks form by sediment
being compacted into layers (may
contain fossils, skeletons of dead
plants/animals)

http://www.answers.com/topic/sediment
Different parts of the Earth were
once under the ocean

For example, if you found a shark tooth
on a hill, you could assume the hill was
once underwater.
http://www.nature.nps.gov/geology/usgsnp
s/misc/gweaero.html
Laws and Scales
The Law of Superposition says that
sedimentary layers form with the oldest
layers on the bottom and newest on the
top.
 The Geological Time Scale shows the
different periods the Earth went through.

http://www.enchantedlearning.com/subject
s/Geologictime.html