1. Chapter 2.2 Igneous Rocks Objectives:
recognize magma and lava as the materials that cool to form igneous rocks.
Contrast the formation of intrusive and extrusive igneous rocks
Contrast granitic and basaltic igneous rocks

2. Formation of Igneous Rocks
Formed when hot magma cools and hardens

3. Magma When rocks melt they form magma
Located about 150 km below earth's surface
Lava - when magma reaches Earth’s surface and flows from volcanoes.

4. 2. Intrusive Rocks
Rocks that form from magma below (inside) the surface

5. 2. Extrusive Rocks
Extrusive igneous rocks are formed as lava cools on the surface (outside) of Earth.
Cools quickly and produces fine grained crystals - example pumice and obsidian

7. B. Classifying Igneous Rocks
Intrusive OR Extrusive
INSIDE OR OUTSIDE

8. Basaltic Rocks Dense, dark-colored rocks.
Formed from lava that is rich in iron and magnesium and poor silica

9. 2. Granitic Rocks
Light-colored rocks of a lower density that basaltic rocks.

10. 3. Andesitic Rocks
Have compositions between those of basaltic rocks.