The Rock Cycle
Indicates
agents of
change and
the types of rock that
are present on Earth
and under what
conditions they change
Rock Cycle
Identify the agents of change…
Sedimentary
Metamorphic
Igneous
Rock cycle processes
Cooing and hardening
Solidiification
lithification
Weathering and erosion
Sedimentation
lithification
Heat and pressure from internal
and tectonic forces
Litho- prefix meaning stone or
rock
Lithification
Igneous
Cooling
Solidification
rapid
Cooling
Solidification
slow
Sedimentation
&
Deposition
Cementation
of
sediments
Igneous rocks
• From fire…
• Intrusive ; formed inside Earth
• Extrusive; formed outside Earth
(surface)
• Mafic or felsic
• Magnesium and aluminum rich or
quartz rich…
Igneous Rock
Mafic & Extrusive
Igneous Rock, Basalt Columns
Sedimentary rock
• Formed from weathered and eroded
rock particles
• Could not be the original rocks
• WHY or why not?
Layers in Sedimentary Rock
How does it form?
Grand Canyon
• If Grand Canyon consists of layers of
millions of years of sedimentary rock, how
did it form?
• When did the layers form?
• When did the weathering and erosion take
place?
• Were the rocks or the canyon, original
rocks on Earth? Why or why not?
Is this the first rock on Earth?
Sandstone
Desert Geysers eject many
minerals, heat and water
Metamorphic Rock
• Formed from heat and pressure
• Formed from tectonic
pressures
• Re-crystallization
• Banding
• Distortion
Word meaning?
•Meta means change,
transformation
•Morphic means
referring to the form or
structure of an object
How does metamorphic rock
form?
• Igneous rock that has weathered and
eroded over time
• Note the globs of volcanic rock that
solidified
• Dark colors due to elements such as
magnesium, aluminum, (iron maybe)
Volcanic rock
weathered by water
and wind.
Iron deposits
• Sedimentary rock
• Sandstone; made from particles of other
rock, finely weathered and compacted;
• Glued with calcite mineral
• On sea floor
• Seas contain abundance of calcite
• Shelled organisms are made of calcite
Extrusive Igneous Rock
Basalt Columns
• Basalt hexagonal shapes
• Devil’s Tower; national monument in
Wyoming
Basalt is extrusive mafic igneous rock
Contains abudance of magnesium
sandstone
granite
• Granite
• The most common intrusive felsic igneous
rock on Earth
• Most common rock of continental crust
• Mostly quartz, horneblende and feldspar
• Chalk is a type of limestone
• Formed on seafloor
• Limestone metamorphosed becomes
marble
Where would we find marble? Why?
Weathered by wind and water
Rock type? Why?
The Giant’s Causeway
Ireland
Stone Mountain, GA
A natural pluton
intrusive igneous rock
Ancient volcanic necks
• Beautiful sandstone landscapes
• Iron oxidized is iron oxide
•
• Fe2 O3(rust)
• Hence the coloring
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The Palisades in Northern New Jersey
Overlooking the Hudson River
Diabase; extrusive igneous (mafic)
Similar to basalt
This region was once overrun by volcanic fields
Prior to the volcanic action, rock was subjected
to tectonic, subduction forces
• What type of rock lies below the Palisades?
The Palisades in NJ overlooking
the Hudson River
Metamorphic folds- bands
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Classic metamorphic rock
Re-crystallization of minerals due to heat
Pressure distorts
Bands of minerals evident
Pressure creates friction that aids in heat
production
• Deep in Earth
Rock Type?
Clastic rock
Rock type? Name for ‘glue’?
Giant’s Causeway, Ireland
Basaltic Hexagonal Columns
Why aren’t fossils found in metamorphic or igneous rock?
Striations of
layered
sandstone
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•
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Sedimentation forms layers
What forms the shape of this rock?
Where is the oldest rock in this rock?
The youngest rock?
WHY?
Volcanic – Igneous
Large or small crystals?
• Desert Geysers in the black rock canyon
of Nevada
• Note the colors of nature
• Orangy red due to oxidized iron
• Yellow- sulfur
• Green is mold/algae
• Water and Hydrogen sulfide and Carbon
dioxide – gases released
Minerals from Earth interior may combine to form rock
Green Italian Marble - Metamorphic
Marble shows classic
re-crystallization
• Distortion
• Hard, dense rock due to pressurization
• Used for government buildings,
monuments,businesses, schools
• Flooring- lasts forever
• Pink, white, green- high polish possible
• Beautiful, functional-valued quarries
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