Rocks: Sedimentary

Lesson Plan - Get It!

Audio:

The picture you saw showed a big group of rocks.

Rocks can be found all over the earth. In fact, the earth's crust is made up of rock!

• Did you know that there are three types of rocks?

Sedimentary, igneous, and metamorphic rocks are the main groups of rocks.

In this series of Related Lessons, found in the right-hand sidebar, you will learn about the three different types of rocks. You will start by learning about sedimentary rocks.

• Are you ready to get started?

Great!

Sedimentary rocks can be found on the surface of the earth. This is where they are formed!

These rocks can be found on land or in water. Most sedimentary rocks form in water. They are formed over hundreds of years when sediments like sand, plants, pebbles, minerals, and mud, pile on top of each other and press together. This causes many sedimentary rocks to have layers.

• Can you see the lines in the canyon pictured above?

This shows the different layers of sedimentary rock. You can also see the different layers in the picture below:

Sedimentary rocks can also be impacted by weathering and erosion. Wind, rain, snow, and hail all affect the rocks on the earth's surface. Moving water, like rivers and streams, also have an impact on the shape and size of rocks.

Sometimes, these forces can break down rocks until they are sediment again. This starts the whole process over again, when the sediment is moved and compacted into a new rock. Scientists can use evidence from weather and water to discover where certain sedimentary rocks were formed.

There are many different types of sedimentary rocks that can be found outside. Siltstone, coal, chalk, flint, iron ore, limestone, shale, rock salt, and sandstone are all examples of sedimentary rocks.

In the Got It? section, you will explore some of these types of sedimentary rocks.