Identifying Rocks

All rocks are classified by how they form. Rocks can form a couple of different ways: Intense heat and pressure Melting and Cooling of Magma/Lava Erosion , compaction and cementation of sediment over millions of years Based on how rocks form, there are 3 types: Igneous Metamorphic Sedimentary

Igneous Are formed when lava cools on the Earth’s surface OR when magma cools down below the Earth’s surface Hints that you are seeing an igneous rock: Bubbles Glassy appearance Big grains of minerals

Bubbles

Glassy Appearance

Big Grains

Metamorphic Metamorphic rocks are made when old rocks change due to heat or pressure inside of the Earth Hints that you are seeing a metamorphic rock: Bending (ribbon) layers Squished Grains

Bending Layers

Squished Grains

Sedimentary Sedimentary rocks are made of sediments (particles) that build up in layers, usually at the bottom of a river or lake. Hints that you are seeing a sedimentary rock: Flat (foliated) layers Mix of particle size

Flat Layers

Mix of Particle Size

Test Yourself by trying to identify the correct type of rock for each of the following pictures

Sample 1 The example is a _____ rock. I know this because _____.

Sample 2 The example is a _____ rock. I know this because _____.

Sample 3 The example is a _____ rock. I know this because _____.

Sample 4 The example is a _____ rock. I know this because _____.

Sample 5 The example is a _____ rock. I know this because _____.

Sample 6 The example is a _____ rock. I know this because _____.

Answers Sedimentary (mix of particle size) Igneous (bubbles) Metamorphic (bending ribbon layers) Igneous (glassy appearance) Sedimentary (flat foliated layers) How did you do???