Weathering and soil formation

Which of these is a type of chemical weathering?

• Frost action

• Hydration

• Temperature variation

• Solution

The movement of water saturated rock debris down steep slopes of mountains is known as -

• Landslide

• Mudflow

• Earthflow

Biological weathering is caused by -

• carbon dioxide

• burrowing animals

• temperature variation

• frost action

The factors that determine the formation of soil are -

• Quarrying

• Topography

• Nature of parent rock

• Road construction

Which of the following processes will most likely contribute to the development of soil?

• Volcanic eruptions that make new land
• Building up of snow in very cold areas
• Migration of animals to warmer climates
• Breaking down of rock by wind, water, and ice

Which of the following describes how micro-organisms influence the chemical characteristics of soil?

• They loosen and mix the soil by digging burrows underground.

• They add inorganic material to the soil by weathering rocks on Earth’s surface.

• They add moisture to the soil by creating pores through which water can move.

• They add organic material to the soil by breaking down the remains of plants and animals.

A rock containing iron becomes soft and crumbly and reddish in color.  It probably has been chemically weathered by...

• water
• carbon dioxide
• oxygen
• acid rain

Living organisms in soil help to...

• slow rate of soil formation
• build up the C horizon
• mix the soil and make humus
• prevent the formation of humus

What is mechanical weathering?

• Process through which rocks are physically broken into smaller pieces.
• Rocks are broken down through chemical changes.
• Rocks are worn away from acid in plant roots.
• Rocks broken down by machinery.

Farmers prefer to plant crops in soil that is rich in nutrients. Which of these soil types would often contain the most nutrients?

• soil that has many large rock particles in it

• soil that allows water to drain very easily

• soil with a bedrock very close to the surface

• soil with a lot of decomposed organic matter