Digging the Earth's Crust


the Earth from orbit

This lesson developed by Reach Out!

Recommended Age Groups: Later Elementary, Middle School


Guiding Questions:

1. What is the Earth's crust?

2. What is soil?

3. Are there different types of soil?


Objectives

Concepts:

Principles:

Facts:

Skills


Materials:

  1. Pie plate or sturdy paper plates
  2. Access to many different kinds of soil
  3. Clear plastic or glass jars (large baby food jars or peanut butter jars work well)
  4. Labels for soil sample jars
  5. Magnifying glass
  6. Water
  7. Globes and maps
  8. Digging spoons, trowels, spades
  9. Sturdy bag or box to put jars and tools in while going out to dig and find soil samples
  10. Pen or pencil
  11. Handout

Room Preparation

Ample elbow room and place to keep soil sample jars.

Safety Precautions

None.


Procedures and Activity

Introduction

Discuss the following questions and share ideas:

  1. What is the Earth's crust?
  2. What is soil?
  3. Are there different types of soil?

Briefly go over these questions to come up with some basic understandings. Review the concepts, principles, and facts listed above. Look at a globe and find large bodies of water and large and well-known rivers that over the years have carved a path in the Earth's crust—such as the Grand Canyon in Arizona.

Activity

  1. Make labels and put one on each jar for clay, gravel, humus, loam, rock, sand, and silt.

  2. Put jars, digging spoons, or trowels in a bag or box.

  3. Go outside and try to get samples of each kind of soil. Put the samples in their own jars.

  4. Inside, get out magnifying glass. Put a little sample of each kind of soil in the pie plate, one sample at a time. Examine it with the magnifying glass. On the handout, write down the color, texture, and materials you see and find in each soil sample.

  5. Add a few teaspoons of water to each pie plate to make the soil damp. Look to see what happens. Do the soil samples take in or absorb the water? Do the soil samples become like mud? What color do you see? Touch each wet soil sample. What does it feel like? Slimy? Sticky? Slippery? Hard?

  6. Leave the wet soil samples out to dry on a shelf near a window. Watch what happens to each type of soil as it dries out. When soil samples are dry, look at them again. Is the color and texture different from when we first dug them up? Which ones seemed to dry faster than the others?

  7. Think about where we would want to use these different kinds of soils. For example, what kind of soil would you want to build a house on? A road? Which soil would be great for gardening or farming? Why? Which soil would you use on a nature path or walking area? Which soil is best for sandboxes? Which soil would you want at the bottom of a pond or lake? Why?

Evaluation

Ask again,

  1. What is the Earth's crust?
  2. What is soil?
  3. What are some different kinds of soil?

Listen for evidence of new understandings about what the Earth's crust is, what different kinds of soil there are, and given the characteristics of soils, how we use them for different purposes.


Extension Ideas


Careers Related to Lesson Topic


Prerequisite Vocabulary

Clay
Soil that gets hard when baked or fired, and sticky and plastic-like when it gets wet. Light in color.

Crust
The Earth's outer surface and layer of material.

Gravel
Soil made up of lots of little rocks and pebbles.

Humus
Soil material that comes from the decaying and decomposing of plants, animals, and insects. It is called "organic," is usually a dark brown or black color, and is a very important part of soil used for growing plants. Decayed materials provide minerals and other food for plants growing in humus.

Loam
Soil that is a mix of sand and clay.

Organic
Material that is made up from the decaying and decomposing of dead plants, animals or insects. Humus soil is made up of organic material.

Rock
A bunch or hunk of soil, pebbles and stone material. Rock is made from soil, stones, and pebbles being heated up and pressed upon for a very long period of time. They are very hard and do not have humus or organic material, so are not any good for growing plants. Rocks have a variety of colors depending on the soil and pebbles they were made of and the minerals that they absorbed over time from water passing over them.

Sand
Loose and light soil that is formed by the breakdown of rocks.

Silt
Soil made up of lots of little pebbles, even smaller pebbles than found in sand.

Soil
The top layer of our Earth that we grow things in, build buildings on, and dig tunnels under. We often call it dirt.


To Lessons by Subject or Age Group

To Michigan Reach Out! Home

Let us know what you think! E-mail our webmaster

Last revised 23 Jan 05