Earth Is Made of Plates

Lesson Plan - Get It!

Audio:

Plate tectonics is a scientific theory stating that the earth's crust is divided into large plates on the surface.

These plates are moved by convection currents in the mantle. Convection currents, pictured below, occur when warmer magma is pulled upward, while cooler magma sinks.

These currents are responsible for pushing and pulling plates, causing collisions along plate boundaries.

There are two types of crustal plates: oceanic and continental.

• Can you predict which type is more dense?

Consider this image.

• Which type of plate seems to be sitting lower in the asthenosphere (or mantle)?

If you guessed oceanic, you are correct!

Oceanic crust is denser than continental crust. It is made of basalt, an igneous rock that forms at divergent plate boundaries. We'll take a closer look at basalt in just a moment.

For now, let's focus on the continental crust, which is made up of granite. It is responsible for creating landmasses and landforms on the earth's surface.

Oceanic and continental plates interact along the edges, or as scientists sometimes call them, boundaries. There are three main types of boundaries that you will investigate further.

But first, watch the video below for an overview on plate tectonics.

Now, use the following resources to build onto what you just learned and explore the three types of plate boundary interactions. Notice that there can be oceanic-oceanic, continental-continental, and oceanic-continental interactions.

What are the different types of plate tectonic boundaries?

Understanding plate motions

As you explore, organize your learning into a foldable based on the following directions and example.

1. Fold a sheet of paper in half hot-dog style (long ways).
2. Then, cut three flaps of equal size into one of the halves.
3. Now, you are ready to label and complete based on the example below!

• Did you learn anything new?

Happily, plates move very slowly, leading to change over time.

• Can you imagine if plates collided quickly?

In the Got It? section, you will look at plate identification and boundary interactions on the earth's surface.