1. Igneous rocks

2. Video Quiz True or False?1
Igneous rocks are still forming in fiery places today. 2
Weathering makes rocks harder. 3
Sediments harden into rock through lithification. 4
During metamorphism, limestone might change into marble 5
In the rock cycle, igneous, sedimentary and metamorphic rock can change into one another.

3. 5 Igneous Rocks Section 5.1: What are igneous rocks?
Section 5.2: Classification of Igneous Rocks

4. Section 5.1
What are igneous rocks?
Objectives
Summarize igneous rock formation. Describe the composition of magma.
Igneous rocks are the rocks that form when molten material cools and crystallizes.

5. Igneous Rock Formation
What are igneous rocks?
Igneous Rock Formation
Lava is magma that flows out onto Earth’s surface.
Igneous rocks form when lava or magma cools and minerals crystallize.

6. Igneous Rock Formation
What are igneous rocks?
Igneous Rock Formation
Magma formation
Magma can be formed either by melting of Earth’s crust or by melting within the mantle.

7. Draw and Label a volcano, lava, and magma.
(in your workbook)

9. Igneous Rock Formation
What are igneous rocks?
Igneous Rock Formation
Magma formation
The four main factors involved in the formation of magma are temperature, pressure, water content, and mineral content.

10. What are igneous rocks?
Magma formation
Temperature generally increases with depth in Earth’s crust. This temperature increase is known as the geothermal gradient.
How deep in Earth do you have to go to reach 1000°C?
How hot is it at 3000km?

11. Flash cards
1. What is lava?
2. What is magma?

12. Classification of Igneous Rocks
Objectives
Classify different types and textures of igneous rocks. Recognize the effects of cooling rates on the grain sizes in igneous rocks.

13. Section 5.2
Classification of Igneous Rocks
Classification of igneous rocks is based on mineral composition, crystal size, and texture.

14. Where Igneous Rocks Form
Classification of Igneous Rocks
Where Igneous Rocks Form
When magma cools and crystallizes below Earth’s surface, intrusive rocks form.
Magma that cools and crystallizes on Earth’s surface forms extrusive rocks.

16. Classification of Igneous Rocks
Texture
Texture refers to the size, shape, and distribution of the crystals or grains that make up a rock.
We use texture to tell us if a rock was intrusive or extrusive.

17. Texture When lava flows on Earth’s surface, it cools QUICKLY.
Section 5.2
Classification of Igneous Rocks
Texture
Crystal size and
cooling rates
Extrusive Rocks:
When lava flows on Earth’s surface, it cools QUICKLY.
Crystals are MICROSCOPIC

18. Texture Crystal size and cooling rates Intrusive Rocks:
Classification of Igneous Rocks
Texture
Crystal size and cooling rates
Intrusive Rocks:
When magma cools slowly below Earth’s surface
Large crystals to form.

19. Texture Porphyritic texture large, well-formed crystals
Classification of Igneous Rocks
Texture
Porphyritic texture
large, well-formed crystals
surrounded by finer-grained crystals of the same mineral or different minerals.

20. Texture Vesicular texture spongy appearance
Classification of Igneous Rocks
Texture
Vesicular texture
spongy appearance
results of gas bubbles trapped in lava

21. What is the grain size of an intrusive rock?
Flash cards
Give 2 examples of intrusive igneous rocks.
What is the grain size of an intrusive rock?
What is the grain size of an extrusive rock?
Give 2 examples of extrusive igneous rocks.
How are intrusive igneous rocks formed?
How are extrusive igneous rocks formed?