1. There are 3 Major (Geologic) Rock Groups Not the Rolling Stones, Kiss, or Van Halen 1. Igneous Rock 2. Sedimentary Rock 3. Metamorphic Rock Rocks are made of minerals and make up Earth’s solid crust

2. A. Igneous Rock - Forms when a hot, molten liquid, below ground, called magma, crystallizes (cools and solidifies). Magma forms 3 ways: 1. Rock is heated 2. Pressure released 3. Change composition Basalt lava (glowing rock) oozes over basalt lava flow Holt Online Visual: Comparing Int. & Ext Igneous Rocks

3. a. Intrusive Igneous Rock -Forms or crystallizes inside Earth -slow cooling

4. b. Extrusive Igneous Rock -Forms on surface (exterior) of Earth -Fast cooling

5. Fine-grained-made of interlocking crystals. Ex: basalt - the most common extrusive igneous rock BASALT

6. More Igneous Rocks… Course grained texture= Granite, the most common intrusive.

7. Sedimentary Rock *There are 3 types of sedimentary rocks. *Often times, sand, mud, pebbles, or shells settle out in wind and water, get compacted and/or cemented together, and harden into rock. Here, rocks hardened in layers called strata from a process known as… stratification.

8. 3 Types of Sedimentary Rock 1. Clastic -forms when rock or mineral fragments are cemented together.

9. 2. Chemical forms when minerals crystallize out of solution, such as sea water, to become rock.

10. 3. Organic forms from the remains of once-living plants and animals. Ex: Limestone Coal Coal Chalk Chalk

11. Metamorphic Rock -Rocks that have undergone a change in texture, structure, or composition. -Changes in heat and pressure cause rocks to change from one form to another.

13. Rocks are made, destroyed, and created again, in a process called the Rock Cycle