Lesson Plan - Get It!
Each year, more than four million people visit the Grand Canyon. What type of rocks are people traveling from all over the world to see?
Before you begin this lesson, take some time to review what you learned in the previous Related Lesson on igneous rocks, found in the right-hand sidebar.
Write a few sentences explaining how igneous rocks are formed. Have a teacher or parent check your writing.
In this lesson, you will investigate how sedimentary rocks are formed, their characteristics, and how they are used in everyday life.
To start, look up the definition for the term "sediment." If you do not have a dictionary available, use Merriam-Webster’s Online Dictionary. After you have looked up the definition, think about how this definition could relate to sedimentary rocks. Discuss your ideas with a teacher or parent.
Sediment consists of small bits of rock, minerals, and sand. Sediment is created by erosion, a process 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 of time, 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 begins to cement together, forming a rock. Sedimentary rocks are often formed at the bottom of lakes or oceans.
Typically, sedimentary rocks are softer than other types of rocks and will 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 types of rocks because they form around the remains of dead animals and plants. Examples of sedimentary rocks include limestone, sandstone, coal, and flint.
To continue learning about sedimentary rocks, watch the Scholastic StudyJams! Sedimentary Rocks slideshow. When you visit the StudyJams! site, just click the green Slide Show button. You will Test Yourself later in the lesson.
Look at the image at the beginning of the lesson. The Grand Canyon is made mostly of sedimentary rocks. What features do the rocks have that enable you to infer that they are sedimentary? Knowing the Grand Canyon is made mostly of sedimentary rocks, how do you think it was formed? Discuss your responses with a teacher or parent.