1. Igneous Rocks Chapter 3.2

2. Formation Form when magma or lava cools and hardens.
Magma: inside Earth
Lava: outside Earth

3. Where they are made? https://www.youtube.com/watch?v=VKemqTbKpJ0
INTRUSIVE IGNEOUS ROCKS
Inside Earth

4. EXTRUSIVE IGNEOUS ROCKS
~Outside earth

6. Texture of the Rocks? Igneous rocks have different textures.
Texture is how a rock looks and feels.
Texture is based on the size of crystal grains in the rock.

7. Crystal Size is Determined by:
cooling time

8. crystal size
cooling time

9. Large Crystals Indicate
long cooling time
Small Crystals Indicate
short cooling time

10. SLOW cooling-large enough crystals to see with your naked eye
Intrusive
Extrusive
form on or near the surface
QUICK cooling -small or no crystals
form below the
surface
SLOW cooling-large enough crystals to see with your naked eye

11. Characteristics used to classify igneous rocks

12. Texture
glassy }
extrusive
fine

13. Texture
coarse }
intrusive
very coarse

14. Porphyritic: When you have a mix of large and small crystal grains.
This rock experienced two
cooling situations.

15. Wrap Up…show me what you learned today
Wrap Up…show me what you learned today! Be prepared to come up to the board to answer!!
Lava flows:
a. On the Earth’s surface b. Inside the Earth
c. On the surface AND inside the Earth d. NONE of these
Describe how cooling rate affects the size of the grains in an igneous rock
Crystals form in a molten rock as it:
a. Cools b. Loses water
c. Gains water d. Heats up

16. How do igneous rocks form?
What are extrusive igneous rocks?
What are intrusive igneous rocks?
What term refers to the size and arrangement of crystals in an igneous rock?
8. What is a porphyritic rock?

17. Be able to fill in the empty boxes in the chart below