Introduction to Igneous Rocks Audience: 9-12 th Grade Earth Science Class The purpose of this tutorial is to serve as a review of presented concepts involving igneous rocks and igneous rock terms.The purpose of this tutorial is to serve as a review of presented concepts involving igneous rocks and igneous rock terms. Objectives:Objectives: Describe the processes that form the different kinds of igneous rocks.Describe the processes that form the different kinds of igneous rocks. Explain how crystal sizes of igneous rocks indicates the rate of cooling.Explain how crystal sizes of igneous rocks indicates the rate of cooling. Explain how crystal size can also determine whether a rock is intrusive or extrusive.Explain how crystal size can also determine whether a rock is intrusive or extrusive. Created by: Kelly L. Taunt Look for the arrow buttons to move you forward or backward in this tutorial

All igneous rocks begin as magma As with other rocks, igneous rocks are classified by their mineral composition and texture.

Igneous Rock Color Felsic: Light colored, formed from magma with a large amount of silica. Mafic: Dark colored, formed from magma with a lot of iron and magnesium. Intermediate: Not too dark or too light

Which building do you think took longer to build? Skyscraper? Playhouse?

So as with the buildings on the previous slide, a large building will take longer to build. Igneous rocks that have a long time to cool will have: LARGE crystals A small playhouse may be built in a small amount of time. So igneous rocks that cool quickly will have: small crystals

Practice Quiz ( 2 Slides total): Click the correct answer with your mouse to see if you are correct. Cooled Quickly Cooled SlowlyYES! Try again!

Cooled Quickly Cooled Slowly Correct! Try Again

Which person/people will stay warmer longer? Her? Them?

Just like the couple inside next to the fireplace (inside the house), rocks that are IN the Earth stay warmer longer. Igneous rocks that form IN the Earth are called INSTRUSIVE igneous rocks. Inside the Earth.

Just like the girl outside, rocks that are OUTSIDE (exiting the Earth) cool quickly. Igneous rocks that are formed outside of the earth’s surface are EXTRUSIVE igneous rocks. On the Earth’s surface, outside of the Earth.

Since rocks that cool on the outside of the Earth cool faster, extrusive igneous rocks usually have: small crystals Rocks that are on the inside of the Earth take longer to cool because they are near a heat source, therefore, intrusive rocks usually have: LARGE crystals

Can you if this rock is intrusive or extrusive based on crystal size? Intrusive Extrusive Correct! Try Again

Intrusive Extrusive Correct! Try Again Can you if this rock is intrusive or extrusive based on crystal size?

Intrusive Extrusive Correct! Try Again

Are you ready for a quiz? Yes, Let’s Go! Click here. No, I need to review types of magma. No, I need to review crystal size. No, I need to review intrusive and extrusive rocks.

An igneous rocks that forms on the outside of Earth’s crust would be classified as a(n) ________. A. extrusive B. felsic C. intrusive

A mafic igneous rock would be: A. Light colored B. Dark colored C. Intermediate

A rock that has small crystals probably formed in which location? A. Outside of a volcano B. Deep inside a volcano C. Under the Earth’s crust

The rock below would be classified as a(n): ________________ A. Mafic B. Felsic C. Intermediate

The rocks below probably formed ____________, and have __________ crystals. A. Slowly, Large B. Slowly, Small C. Quickly, Small

When an igneous rock has large crystals, it probably formed ____________. A. Quickly B. Intermediate C. Slowly

Intrusive igneous rocks have _______ crystals. A. Small B. Large C. Intermediate

Rocks that form outside of the earth are called what? A. Intrusive B. Extrusive C. Exterior

All igneous rocks originally start as _______. A. Other rocks B. Magma C. Sediments

The rock below represents what type of igneous rock? A. Felsic, Intrusive B. Mafic, Intrusive C. Felsic, Extrusive

GREAT! Try one more time?