Fremont Magnet Elementary

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Rock Cycle

Standard 4 a Students know how to differentiate among igneous, sedimentary, and metamorphic rocks by referring to their properties and methods of formation (the rock cycle).

1. Mineral Identification Review

Which of the following processes usually causes the most gradual change in Earth's surface?

  mudslide
  volcano
 
erosion

Which of the following does not normally make rapid changes in Earth's surface?

    landslide
 
stream erosion
 
earthquake

2. How are rocks made?

There are 3 types of rocks: igneous, metamorphic and sedimentary.Each type of rock is made in a very different way.  To learn more about rocks click here to watch a brainpop movie about rock types.

Igneous Metamorphic Sedimentary

Picture link

Brainpop Rock Cycle

Mystery of the floating rock

 

3. How is igneous rock made?

 

Deep inside the Earth the temperature is very hot.  It is so hot that it melts rock.  The melted rock is called magma.  When a volcano erupts the magma pours out.  When magma comes out of the volcano it is called lava.  Once it cools it becomes igneous rock.

This mountain is made of cooled magma.  It used to be a volcano, but after many years of weathering and erosion the outer part of the volcano wore away and all that is left is the cooled magma that was inside the volcano.  What kind of rock is this?

 

4.  How is sedimentary rock formed?

You know that rocks break down through weathering.  The broken rocks turn into sediment.  Sediment is cemented into sedimentary rocks.  Sedimentary rocks are made at the surface of the Earth, not deep underground like metamorphic rock. Because sedimentary rock is made from layers of sediment, this is the kind of rock in which you find dinosaur fossils.  Look closely at these sedimentary rocks.  Can you see shells imbedded in the rock?

Can you see the layers in the sedimentary rock below?


 

5. How is metamorphic rock formed?

The weight of the ground presses down on rocks that are deep under the surface.  Metamorphic rocks are made when underground rocks are pressed and heated.  They are not hot enough to melt and turn into magma, but they are heated enough to change them from sedimentary to metamorphic.

Look at the lines in this rock.  They are bent and wavy.  You can see how pressure and heat have changed the layers of sedimentary rock into a metamorphic rock.

How 6. What is a rock cycle?

Rocks are slowly changing.  A rock can start as a piece of sediment, become a sedimentary rock, as it is pushed deeper into the Earth it can change into a metamorphic rock.  Then it can melt, become magma that is shot to the surface through a volcano and cool to become an igneous rock.  It can go through this change over and over and over, that is why it's called a cycle.  Here is a picture of how it works.

1. Which type of rock forms in layers?

    igneous
 
sedimentary
 
metamorphic

 

2. What's the main difference between lava and magma?

    temperature when formed
 
location
 
type of rock

 

Once a rock has changed to a metamorphic rock, which of these can it later become?

    a sedimentary, igneous, or another metamorphic rock
 
only another metamorphic rock
 
an igneous or a similar metamorphic rock

 

Why are fossils not usually found in metamorphic rock?

    no organisms were alive when metamorphic rock formed
 
Metamorphic rock is formed from processes that destroy fossils
 
Metamorphic rock is too hard to break open to find fossils

 

 

Here is a great page with lots of info and pictures of rocks

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