Rocks Rock!!!
Rocks
• Rock: A mixture of minerals, rock
fragments, volcanic glass, organic matter or
other natural materials.
Rock Uses
• Rocks have been used throughout history
for buildings, weapons, tools, and in art.
Types of Rocks
• There are three main categories of rocks
– Igneous
– Sedimentary
– Metamorphic
Igneous Rocks
(ig-nee-us)
Igneous rocks
• Igneous rocks: rocks formed when magma
or lava cools and hardens.
Igneous is from
Latin, meaning
“born of fire”.
http://www.absorblearning.com/media/attachment
.action?quick=12z&att=2795
Lava is found on the surface, magma
is found underground.
Igneous rocks
• Intrusive: forms below the surface when
magma cools slowly.
• It has large crystals (granite).
http://www.msistone.com/granite-countertops/
Igneous rocks
• Extrusive: formed when lava cools quickly on
the surface of the Earth.
• Crystals are small (obsidian and basalt)
Igneous-examples and uses
• Granite: buildings, bridges, and counters
• Basalt : gravel
• Obsidian: knives
Famous Igneous Rocks
Giants Causeway
Stonehenge
Sugarloaf
Mtn.
Easter Island
The black stone
Machu Picchu
Mt. Rushmore
Mt. Fuji
Sedimentary Rocks
(said-ah-men-tarry)
Sedimentary rocks
• Sediments: loose materials, such as rock
fragments, mineral grains, and the remains
of once living organisms
• Sediments are moved by wind, water, ice, or
gravity.
Sedimentary rocks
• Sedimentary: rock formed when sediments
are compacted and cemented together. Rock
may feel grainy or sandy and weak.
Sedimentary rocks
• Many fossils are found in sedimentary rocks.
Sedimentary-examples and uses
• Sandstone: building materials
• Limestone: used to make cement
Famous Sedimentary Rocks
Monument Valley
Angkor Wat
Uluru (Ayers Rock)
Chichen Itza
Sphinx
Haolong Bay
Metamorphic Rocks
(met-ah-more-fic)
Metamorphic rocks
• Metamorphic: rock that forms when heat,
pressure, or chemicals act on a rock to
change its form or composition. Layers are
often seen in these rocks.
Limestone
into marble
Granite into Gneiss
http://www.classzone.com/boo
ks/earth_science/terc/content/vi
sualizations/es0607/es0607pag
e01.cfm?chapter_no=visualizat
ion
Metamorphic rocks
• Pressure and heat squish the rock into
interesting patterns
http://io9.com/you-probably-never-realized-howmarble-is-harvested-bu1649511624?utm_campaign=socialflow_io9_facebook
&utm_source=io9_facebook&utm_medium=socialflo
w
Marble Quarry
Metamorphic-example and uses
• Marble: buildings and sculptures
• Slate: flooring, roofing, walkways, and
chalkboards
Famous Metamorphic Rocks
Parthenon
Trevi Fountain
Taj Mahal
Review
• What is the difference between a mineral
and a rock?
– Minerals have specific chemical compositions,
rocks are a random assortment of materials
– Rocks can have organic materials (shells and
plants) mixed in
– Rocks may not have a crystal structure
VS.
What are the three types of rocks?
• Igneous
• Sedimentary
• Metamorphic
Rock Cycle
Rock Cycle
• Rock cycle: a model that describes how
rocks slowly change from one rock type to
another rock type over time.
Rock Cycle
Rock Cycle
• Changes to rocks
occur due to
melting, cooling,
weathering and
erosion,
compaction and
cementation, and
heat and
pressure.
Process of the rock cycle
• Melting rock to form magma or lava
– Usually happens deep underground
https://www.youtube.com/watch?v=svAPyyUJUCo
Processes of the Rock Cycle
• Cooling of lava to form igneous rock
https://www.youtube.com/watch?v=Fcz3vBdI7Nc
Weathering and erosion work together
to wear down and carry away rocks on
Earth’s surface
Physical Weathering
• Rock is physically broken down into smaller
pieces
Chemical Weathering
• The process that breaks down rock through
chemical changes.
Erosion moves rock particles using
four different methods
Processes of the Rock Cycle
• Sediments compact and cement together to
form sedimentary rock.
http://www.youtube.com/watch?v=JflERikuadE
Heat and Pressure form
metamorphic rock
Rock Cycle Quiz
• How does one rock change into another?
Use your rock cycle chart to figure it out!
1. Igneous to sediments?
• Weathering and erosion
• Is there another path that could occur?
2. Sedimentary rock to
Metamorphic?
• Heat and pressure
3. Igneous Rock to Magma?
• Melting
4. Igneous Rock to Metamorphic?
• Heat and pressure
5. Igneous Rock to Sedimentary
Rock?
• Weather and erode into sediments
• Sediments compact and cement into
sedimentary rock.
6. Metamorphic Rock into
Sedimentary Rock?
• Weather and erode into sediments
• Sediments compact and cement into
sedimentary rock.
7. Sedimentary Rock to Igneous
Rock?
• Sedimentary rock
undergoes heat and
pressure to become
Metamorphic rock, then
it melts to become
magma, then cools to
become Igneous rock.
OR
• Sedimentary rock melts
into magma then cools
into Igneous rock
The End of
Rocks!
http://www.youtube.com/watch?v=53lMdHzvGCQ
Famous Rocks around the World
• http://academic.brooklyn.cuny.edu/geology/
grocha/monument/rocks.html