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-ah-MORE-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 eroded- have 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.htmhttp://geology.about.com/od/rocks/ig/metrockindex/rocpicschist.htmhttp://www.cotf.edu/ete/modules/msese/earthsysflr/rock.htmlhttp://adventuresinscience.edublogs.org/tag/extra-credit/http://flexiblelearning.auckland.ac.nz/rocks_minerals/rocks/mudstone.htmlhttp://www.fi.edu/fellows/payton/rocks/create/metamorph.htmhttp://www.fi.edu/fellows/payton/rocks/create/igneous.htmhttp://www.fi.edu/fellows/payton/rocks/expert/gneiss.htmhttp://www.fi.edu/fellows/payton/rocks/create/sediment.htmhttp://www.up.ac.za/academic/geog/community/damiano.htmhttp://www.teachnet-lab.org/ps101/bglasgold/rocks/lesson3rockcycle.htmhttp://www.brynmawr.edu/geology/102/lectures/lectures.htm