O: You will be able to explain rocks and the rock cycle.

Do Now: take out your pre-test.

Rocks

• Scientists define rock as a naturally occurring solid mixture of one or more minerals and organic matter.

• Rocks are always changing.

• The Earth recycles rocks.

Uses of rocks.

What shapes the Earth?

• Erosion

• Deposition

• Weathering

Weathering

• The process in which water, wind, ice, and heat break down rock is called weathering.

• Weathering is important because it breaks down rock into fragments.

Erosion

• The process by which sediment is removed from its source is called erosion. Water, wind, ice, and gravity can erode and move sediments and cause them to collect.

• Sediment is another name for small pieces of rock, dirt, or dust.

Deposition

• The process in which sediment moved by erosion is dropped and comes to rest is called deposition.

• Sediment is deposited in bodies of water and other low-lying areas. In those places, sediment may be pressed and cemented together by minerals dissolved in water to form sedimentary rock.

The Rock Cycle

• Rocks are constantly changing into new things, this process is called the rock cycle.

Homework

• 1. Why are rocks important to us? Give at least three reasons.

• 2. How does weathering shape the Earth’s surface?

• 3. What is the difference between erosion and deposition?

• 4. Why is it called the rock cycle?

O: You will be able to identify the three main types of rocks.

Do Now: What are the three main types of rocks? What makes them

different?

Three Main Types of Rocks

• Sedimentary

• Igneous

• Metamorphic

Sedimentary Rocks

• Formed from the pieces or sediments of other rocks.

• The weight and pressure causes them to bond together.

• You can see the little pieces that form it and they keep their properties.

Igneous Rocks

• Igneous comes from the Latin word for fire.

• Igneous rocks are formed from cooling magma.

• There are a couple different types of Igneous rocks.

Metamorphic Rocks

• Metamorphic rocks undergo a chemical change and turn into a whole rock.

• They form under intense heat and pressure.

How are rocks classified?

The size, shape, and positions of the grains that make up a

rock determine a rock’s texture.

Homework

• 1. What type of rock do you think that there is the most of? Why?

• 2. Why can sedimentary rocks look very different than other sedimentary rocks?

• 3. Why do scientists look at composition and texture of rocks?