Bell Work: 10/13/11Bell Work: 10/13/11Work on Rock Cycle Paper Plate.Work on Rock Cycle Paper Plate. If you are finished with paper plate, do the If you are finished with paper plate, do the

section Review questions pg. 367.section Review questions pg. 367.

dep

ositio

n

dep

ositio

ncompaction & compaction & cementationcementation

solidificationsolidification

deposition

deposition

Objectives

Identify the major processes that drive the rock cycle.

How are igneous rocks formed? How would the texture of igneous rocks change if the

rock cooled quickly vs. slowly? What is the difference between intrusive igneous

rocks and extrusive igneous rocks?

Label a diagram that depicts the three different rock types.

Igneous Rocks: From Fire!

Igneous rocks get their name from the Latin word for fire “igneus”. The name is appropriate because these rocks are born of fire.

Igneous Rock

• Discuss with your group:– Where do igneous rocks come from?

• ___________ _________ forms when hot, liquid rock, or __________, cools and solidifies.

• The type of igneous rock that forms depends on the composition of the magma and the amount of time it takes the magma to cool.

Igneous rockmagma

Igneous Rock

• The longer it takes for magma or lava to cool, the more time mineral crystals have to grow.– __________ = _____________ = ____________

• Examples of coarse-grained igneous rocks:– Granite– Gabbro

more time larger crystals coarse texture

Igneous Rock

• The less time magma takes to cool, the less time crystals have to grow.– __________ = _____________ = ____________

• Examples of fine-grained igneous rocks:– Obsidian– Basalt

less time smaller crystals fine-grained

Group Activity

• Rank the rock samples by how fast they cooled.

• Pay careful attention to the grain size of each rock.

• Write the names of the rocks in order from fastest cooling to slowest cooling.

Igneous Rock Formations

• Rock formed from the cooling and solidification of magma beneath the Earth’s surface is called ____________ ___________ _________.

• Rock that forms from magma that erupts, or extrudes, onto the Earth’s surface is called ____________ ___________ _________.

Igneous rockIntrusive

Extrusive Igneousrock