Igneous Rocks Chapter 3.2

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

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

EXTRUSIVE IGNEOUS ROCKS ~Outside earth https://www.youtube.com/watch?v=J03B2uyObL8

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.

Crystal Size is Determined by: cooling time

crystal size cooling time

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

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

Characteristics used to classify igneous rocks

Texture glassy } extrusive fine

Texture coarse } intrusive very coarse

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

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

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?

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