Chapter 4 Test Weathering and Soil Formation

The agent of mechanical weathering in which rock is worn away by the grinding action of other rock particles is called...

• erosion
• cracking and peeling
• abrasion
• ice wedging

Ice wedging causes mechanical weathering of rock by means of ...

• release of pressure
• plant growth
• animal actions
• freezing and thawing of water

The growth of plant roots and animal activity may result in 

• mechanical weathering
• erosion
• chemical weathering
• abrasion

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

A hot and wet climate causes weathering to take place 

• slowly
• at the same rate as when the climate is dry and cool
• unevenly
• rapidly

The most important factors in determining the rate of weathering are

• carbon dioxide and acid rain
• abrasion and acids from plant roots
• animal action and oxygen
• rock type and climate

Soil formation begins with the weathering of

• litter
• rock
• the A horizon
• humus

The mixture of rock particles, minerals, decayed organic material, air and water is called...

• gravel
• litter
• silt
• soil

The decayed organic material in soil is called...

• silt
• litter
• humus
• clay

Removing nonrenewable resources such as iron and copper from the ground is called...

• development
• nutrient depletion
• mining
• erosion