Download Igneous Rocks - MrsZ-wiki

By: Ella Breitenfeldt
What are Igneous rocks?
 Igneous rocks form when magma or lava cools.
 Some of the most common rocks are Igneous.
 Basalt, a type of Igneous rock, covers most of the ocean
floor.
 Over 700 Igneous rocks have been named.
Intrusive or Extrusive?
 Intrusive rock forms under earth’s crust after years of
magma slowly cooling.
 Extrusive rock forms when lava cools above earth’s surface.
 Intrusive rock has time to form crystals; you can see the
mineral grains with the bare eye.
 Extrusive rock cools instantly and has no time to form large
crystals; you’d need a microscope to see the mineral grains.
Diorite (intrusive)
Intrusive or Extrusive continued
 Intrusive rock is also called plutonic rock.
 Extrusive rock is also called volcanic rock.
 Intrusive rocks can take up to 100 years to form
completely.
Classification
 You can classify rocks by the minerals they have
within.
 An Igneous rock can either be basaltic, granitic, or
andesitic.
 Basaltic rocks are dense, heavy, dark-colored rocks.
 Granitic rocks are light-colored and have less
density then balsaltic.
Fun Facts
 Most Igneous rocks are plutonic.
 Igneous rocks are the oldest type of rock.
 Granite, a type of Igneous rock, was used to build the
Empire State Building.
 Basalt covers most of the ocean floor.
 95% of the top ten miles of the Earth’s crust is Igneous
rock.
 Only Igneous rocks are formed when lava or magma
cools.
Fun activity for home
Using this project, you can understand how Igneous
rocks are formed.
 Materials:
-half of a chocolate bar
-marshmallow
-cooking pot
-wax paper
-plate
Activity continued
 Do It!
Melt the chocolate bar and the marshmallow in
the pot.
2. When heated, pour the mixture onto the wax paper,
on the plate.
3. Put the mixture into the fridge and check the next
day.
1.


How did the rock change shape-wise?
What do you think would’ve happened if you tilted
the plate?
Thank you!
This slide show was made by Ella Breitenfeldt.
I hope you had fun!