Unit 12: Soil, Sedimentary Rocks, and Fossils

Which of the following is NOT one of the three types of soil?

• clay
• sand
• silt
• mud

Are there minerals in soil?

• Yes
• No

Ellen grabs a topsoil sample in her hand. She rolls it into a ball. The soil feels gritty and the ball falls apart. What part of the topsoil most likely made the topsoil feel gritty?

• clay
• sand
• silt
• humus

When plants, animals, and other organisms die, they break down and become part of the soil. What is this part of the soil called?

• sand
• silt
• clay
• humus

Which of the following best describes soil erosion?

• A.  the breakdown of soil 
• A.  the improvement of soil
• A.  the addition of soil
• A.  the movement of soil by wind or water

Soil is made of

• weathered rocks and minerals
• dead plants and animals
• air and water
• all of the above

Soil formation begins with the weathering of_______.

• Humas
• Subsoil
• Litter
• Rock

The layer of soil which the topsoil is found.

• Horizon A
• Horizon B
• Horizon C
• Horizon D or R

What effect did over plowing and cutting down trees in the Great Plains during the 1930’s?

• It had little effect
• It increased soil fertility
• It was a primary cause of the Dust Bowl
• Farmers had a great harvest

Soil conservation includes all of the following EXCEPT_______.

• Desertification
• Contour plowing
• Terracing
• Crop rotation