Geology Rocks: Sedimentary Rocks

Lesson Plan - Get It!

Audio:

Sedimentary rocks create the Grand Canyon.

In this lesson, you will investigate how sedimentary rocks are formed, their characteristics, and how they are used in everyday life.

Sediment consists of small bits of rock, minerals, and sand. Sediment is created by erosion, where wind, water, or ice breaks down larger rocks or minerals into smaller parts.

Eventually, sediments are carried away by water or wind, and, over a long period, layers of sediment build up on top of each other. This build-up exerts pressure on the lower layers of sediment.

The pressure is so great that the sediment cements together, forming a rock. Sedimentary rocks are often formed at the bottom of lakes or oceans.

Typically, sedimentary rocks are softer than others and often chip or break when struck with a sharp object.

Since sedimentary rocks consist of layers of sediment that build up over time, sedimentary rocks often have visible layers. Sedimentary rocks are also more likely to have fossils than other rocks because they form around the remains of dead animals and plants.

Examples of sedimentary rocks include limestone, sandstone, coal, and flint.

Explore these examples and more as you watch the following video.

Think back to the sedimentary rocks in the Grand Canyon.

• What features do the rocks have that make you infer they are sedimentary?
• Knowing the Grand Canyon is made mostly of sedimentary rocks, how do you think it was formed?

Continue to the Got It? section to show off what you have learned!