Transcript The Rock Cycle - Science A 2 Z

THE ROCK CYCLE
Would you believe that this rock was………
This rock…..?
Don’t be confused! I’ll explain!
All rock (except for meteorites!) that is on Earth today is made of the same stuff as the
rocks that dinosaurs and other ancient life forms walked, crawled or swam over. While
the stuff that rocks are made from stays the same, the rocks do not. Over millions of
years, rocks are recycled into other rocks. Moving tectonic plates help to destroy and
form many types of rocks.
Rock divisions occur in three major
families based on how they formed:
igneous, sedimentary, and
metamorphic. Each group contains a
collection of rock types that differ
from each other on the basis of the
size, shape, and arrangement of
mineral grains.
There are places on Earth that are so hot that
rocks melt to form magma.
Because magma is liquid and usually less
dense than surrounding solid rock, it moves
upward to cooler regions of the Earth. As the
magma loses heat, it cools and crystallizes
into an igneous rock.
Magma can cool on the Earth's surface,
where it has erupted from a volcano
(extrusive rock) or under the Earth's surface,
where it has intruded older rocks (intrusive
rock).
Any rock (igneous, sedimentary, or metamorphic) exposed at the Earth's
surface can become a sedimentary rock. The forces of wind, rain, snow,
and ice combine to break down or dissolve (weather), and carry away
(transport) rocks exposed at the surface. These particles eventually come
to rest (deposited) and become hard rock (lithified).Sedimentary rocks
tell us what the Earth's surface was like in the geologic past. They can
contain fossils that tell us about the animals and plants or show the
climate in an area. Sedimentary rocks are also important because they
may contain water for drinking or oil and gas to run our cars and heat
our homes
Any rock (igneous, sedimentary, or metamorphic)
can become a metamorphic rock.
If rocks are buried deep in the Earth at high
temperatures and pressures, they form new
minerals and textures all without melting. If
melting occurs, magma is formed, starting the
rock cycle all over again..The term
"metamorphic" means "to change form."
Changes in the temperature and pressure
conditions cause the minerals in the rock to
become unstable so they either reorient
themselves into layers (foliation) or
recrystallize into larger crystals, all without
undergoing melting.
When Earth's tectonic
plates move around, they
produce heat. When they
collide, they build
mountains and
metamorphose (met-ahMORE-foes) the rock.The
rock cycle continues.
Mountains made of
metamorphic rocks can be
broken up and washed
away by streams. New
sediments from these
mountains can make new
sedimentary rock.
The rock cycle never stops.
WHAT WE KNOW:
Review
Igneous Rocks are formed ABOVE
ground and UNDER ground.
Under ground they are formed when
MAGMA (like lava- but deep within
the earth) is trapped in a pocket. As
the magma cools (in the pocket) it
becomes IGNEOUS ROCK.
ALSO IGNEOUS ROCK is formed
when volcanoes erupt! When
magma appears above the earth’s
surface it is called LAVA. The lava
cools and becomes igneous rock.
Metamorphic
rocks are rocks that
have "morphed" into
another kind of rock.
These rocks were once
igneous or sedimentary
rocks.
The rocks are under
tons and tons of
pressure, which fosters
heat build up, and this
causes them to change.
Sedimentary Rock:
For MILLIONS of years bits
of the earth have erodedhave been broken down by
WIND and WATER.
•The bits of earth move
through streams to be
deposited in riverbeds, lakes
and oceans.
•Layer upon layer settle unto
each other
•The layers are pressed down
through time and the layers
become ROCK!
ACTIVITY:
*HOW CAN A SUGAR CUBE
MIMIC THE ROCK CYCLE?
*GET INTO GROUPS (3-4 or 5)
*GRAB SUPPLIES!
*FOLLOW INSTUCTIONS ON
WORKSHEET!
Works Cited:
http://www.fi.edu/fellows/payton/rocks/create/sediment.htm
http://geology.about.com/od/rocks/ig/metrockindex/rocpicschist.htm
http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html
http://adventuresinscience.edublogs.org/tag/extra-credit/
http://flexiblelearning.auckland.ac.nz/rocks_minerals/rocks/mudstone.html
http://www.fi.edu/fellows/payton/rocks/create/metamorph.htm
http://www.fi.edu/fellows/payton/rocks/create/igneous.htm
http://www.fi.edu/fellows/payton/rocks/expert/gneiss.htm
http://www.fi.edu/fellows/payton/rocks/create/sediment.htm
http://www.up.ac.za/academic/geog/community/damiano.htm
http://www.teachnet-lab.org/ps101/bglasgold/rocks/lesson3rockcycle.htm
http://www.brynmawr.edu/geology/102/lectures/lectures.htm