Rock Cycle

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Transcript Rock Cycle

Rocks
Three Types
of rock
• Igneous
• Metamorphic
• Sedimentary
Three totally different types of
rock that all basically come
from the same materials
Q: So how do we get such
different rocks?
They all look and act so differently, how do they all form?
Igneous Rocks?
Sedimentary Rocks?
Metamorphic Rocks?
A: The Rock
Cycle!!!
The process of rocks changing from
one type of rock to another
Igneous Rocks
Sedimentary Rocks
Main Concept: Any rock type can be changed
into any of the other two and back again
through the Rock Cycle Metamorphic
depending onRocks
conditions
Igneous
The type of igneous rock depends on how fast it cooled!
Rocks
All Igneous rock comes from molten material
Molten material comes from volcanoes
How to get Igneous Rocks:
Melting of IsMaterial
made from exploding material up here
Is made from cooled magma down here
Can you see the big differences
Cooling Magma
Explosive Volcanism
in these two rocks?
Large Crystals
Lots of holes
Weathering
• If rocks are exposed at the surface; they are exposed to the
elements in the air.
• All the “elements”: rain, wind, animals, plants, ice and even simply
a release of pressure can cause the chemical bonds in rocks to
break apart.
• The process of breaking the bonds in rock and making it “softer”
is called: Weathering!
Erosion
• After a rock has been weathered, it is easy to break.
• If a rock breaks into pieces it becomes easier to move from one
place to another.
• The movement of rock pieces and or soil from one place to
another by natural processes is called: Erosion!
The cliff is slowly falling down!
The pile of sediments here used
to be part of this cliff!
Sedimentary Rock
=cemented
sediments
This Sandstone in Utah
is made from sand
that has been cemented together
The sand here is loose and not cemented together
Can you see the different
layers of sand?
Sedimentary
Rock
Recipe
1. Start at the
Surface
2. Weather (Break Up)
3. Erode (Carry Away)
4. Sedimentation &
Deposition
Layers of sand and sediments
Rain moves sand, dirt, and
rocks down to the ocean
5. Compaction &
Cementation
Igneous rock
© Beadle, 2009
Sediments worn away
gather here!
How to get Sedimentary Rocks:
Weathering
Erosion
Deposition
Cementation
Rocks get broken down
by exposure to water,
wind, etc…
Broken down sediments
are transported towards the sea
and spread out
Broken down rocks fall
apart
Water and pressure helps bond the
particles of sediment together
to make a rock
This is what it
looks like in
real life:
Weathering
(Rock broken down by exposure to rain, wind, etc..)
Cementation
(eventually pieces get
stuck together and
becomes a rock)
Erosion
Deposition
(smaller pieces are spread out across area)
(pieces fall down to
bottom of cliff)
Rivers can do a lot
of this on their own:
You can see lots of sediments
flowing in the river
Deposition is taking
place when the river
meets the ocean
You can see lots of sediments spreading out!
Evaporation:
New rocks can be formed when water is evaporated
When the water leaves, the electrons of the chemicals that
make up the rocks are attracted to each other and cause
clumps of rock to form from the small particles left behind.
Now all that is left are salty rocks that form a dry lake bed
There used to be a nice
deep ocean here
But then the water evaporated…
Limestone is very common in
the mountains of Utah
Q: Where did this limestone originally come from?
A: Underwater!
Limestone is the remains of sea critters shells that have
been compacted together to form rock at the bottom of a sea
Pressure and Heat Lead to
Metamorphic Rocks
• Rocks that get buried again can get squished
and heated to the point that they change!
This rock is called
“Gneiss” (nice).
Q: Can you remember what it
has “morphed” from?
A: Granite!!!
If you look closely, you can see
the same minerals in both rocks!
The rock cycle is an active process that you can
see just about everywhere outside:
The white tops of these
mtn’s are granite= Igneous
Erosion is actively breaking
down the mountains
(forming canyons!)
Deposition:
minerals from the Granite
spreading out as sand!
(This makes the soil of the valley)
Soil is basically all the small broken up pieces of rocks!
Broken down tons of times into smaller
and smaller sediments
Underneath all the sand,
sediment is being compacted
=Sedimentary
The Real Rock Cycle
***You will need to know the process
to make each type of rock!
Rock Cycle with illustrations:
Let’s connect the rock
cycle with plate
tectonics!
Q: What rock will we get
if two continental plates collide?
Plate motion
Cooler Crust
Convection current
Plate motion
Convection current
Hot Mantle
Continental plate collides with Continental Plate causing mountains to form!
Plate motion
Compression
= Metamorphic
Hot Magma
Plate motion
Continental collides with Oceanic:
Cloud
will bringExplosion
falling water
Volcanic
Extrusive Igneous Rock
Label where metamorphic,
igneous & sedimentary rocks
are formed as the numbers
appear:
6
6
6
7
5
2
3
plate motion
3
4
1
Divergent
Hot Mantle
Convergent
plate motion
Cloud
Extrusive Igneous
Intrusive Igneous
Intrusive Igneous
Sedimentary
Metamorphic
Plate Tectonics Rock Cycle
Key: Notice where
metamorphic, igneous &
sedimentary rocks are
processed & formed.
Sedimentary
Metamorphic
Melted rock
Assessment:
Identify where the terms/description
on the left should go in the rock cycle
on the right
•
•
Heat,
Pressure
Extrusive
(Volcanic
Eruptions)
•
•
•
Deposition &
Cementation
Melting
Intrusive
(Cooling &
Crystallization)
•
Weathering &
Erosion