Download Rocks!

Rocks!
Rocks are the solid parts of the earth. Most
rocks are “aggregates” or combinations of
one or more minerals.
The rocks you see around you the mountains, canyons &
riverbeds, are all made of
minerals.
A rock is made up of 2 or
more minerals.
Think of a chocolate chip
cookie as a rock.
The cookie is made of flour,
butter, sugar & chocolate.
The cookie is like a rock and
the flour, butter, sugar &
chocolate are like minerals.
You need minerals to make
rocks, but you don't need
rocks to make minerals.
All rocks are made of
minerals.
There are three main types of rocks:
*igneous
*sedimentary
*metamorphic
Igneous Rocks
Igneous rocks are called fire rocks and are formed either
underground or above ground. Underground, they are
formed when the melted rock, called magma, deep within
the earth becomes trapped in small pockets. As these
pockets of magma cool slowly underground, the magma
becomes igneous rocks.
Sedimentary Rocks
For thousands, even millions of years, little pieces of our earth have been
eroded--broken down and worn away
by wind and water. These little bits of our earth are washed
downstream where they settle to the bottom of the rivers, lakes, and
oceans. Layer after layer of eroded earth is deposited on top of each.
These layers are pressed down more and more through time, until the
bottom layers slowly turn into rock.
Metamorphic Rocks
Metamorphic rocks are rocks that have "morphed" into another kind of
rock. These rocks were once igneous or sedimentary rocks. How do
sedimentary and igneous rocks change? The rocks are under tons and
tons of pressure, which fosters heat build up, and this causes them to
change. If you exam metamorphic rock samples closely, you'll discover
how flattened some of the grains in the rock are.
“Rocks Challenge”
Activity
Question: How can bread represent sedimentary and
metamorphic rocks?
Procedure:
1. Lay a sheet of waxed paper on your desk.
2. Stack your bread on top of the waxed paper.
3. Draw your bread/rock stack and label in your science
journal.
4. Use your ruler and measure the height of the stack using
cm.
5. Record the measurement in your journal.
6. Tell what type of rock this bread stack represents and
why.
Example: This bread stack represents a sedimentary rock
because…
“Rocks Challenge”
7. Lay another sheet of waxed paper on top of the bread
stack.
8. Place your book on top of the stack and press down.
9. Draw the bread stack now in your journal.
10. Measure the height of the bread stack again and record
next to your illustration.
11. Use the scissors and cut your bread stack in half.
12. Write what type of rock the stack represents now and
why.
Example: The pressed stack of bread now represents a
metamorphic rock because…