Igneous Rocks

Pre-Assessment1. Which of the following types of rock is produced by magma that cools deep

below the earth's crust? A. extrusive igneousB. intrusive igneousC. foliated metamorphicD. chemical sedimentary

2. The texture of igneous rock is determined by the rate at which magma A. flows from a volcanoB. coolsC. meltsD. compresses

3. A common igneous rock isA. graniteB. goldC. quartzD. limestone

What is an Igneous Rock?Hint: the word igneous comes from the Latin word ignis

which means fire

An Igneous rock is a rock that is formed from cooled magma or lava

What is the difference between magma and lava?

Answer: Magma is molten rock below Earth’s surface and lava is molten rock above Earth’s surface

Where the molten rock cools plays a BIG part in what type of Igneous rock will be formed

Today we are learning about igneous rocks, but to help us understand, let’s first watch a video about all rocks!

• Extrusive Igneous rocks – these are rocks that form from cooled lava (outside of Earth’s crust)

• The most common example is Basalt

What volcanic islandsare primarily madeof basalt?

• Extrusive igneous rocks cool quickly so that are what we call fine-grained because they have small crystals

• Intrusive igneous rocks – form from cooled magma (molten rock that has hardened inside Earth’s crust)

• The most common example is Granite

• Intrusive igneous rocks cool slowly so they are what we call coarse-grained because they have large crystals