Weathering & Soil Formation Ch 8 Review
Know A-C Horizon and what each layer is made off
Know how plants cause mechanical weather
Know the difference between mechanical and chemical weathering
Concepts to Understand
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The most important agent of chemical weathering is water
Plant roots that force cracks in rocks father apart are an agent of mechanical weathering
The gas that causes rock containing iron to oxidize is O2
Freezing and thawing are an example of mechanical weathering
Acid rain causes very rapid chemical weathering
An area’s climate and plant life help determine what type of soil forms
The soil loss on the southern Great Plains in the 1930s caused the area to be called the Dust
Bowl
When CO2 becomes dissolved in rainwater and sinks into the soil, the result is an acid that can
weather marble
Decayed organic material in soil is called humus
When a material contains air spaces that allow water to seep through, it is said to be permeable
Loam is the best soil for growing plants
George Washington Carver taught farmers in the South in the early 1930’s methods of soil
conservation
The movement of rock particles by wind, water, ice, or gravity is called erosion
Fungi, bacteria, and worms are soil decomposers
The process that breaks down rocks and other materials at Earth’s surface is called weathering
Plant roots do not cause oxidation of the soil
The grinding away of rock by other rock particles carried by wind, water, or ice is called abrasion
The rate of weathering depends on the type of rock and on the climate
The loose, weathered material on Earth’s surface is called soil
Contour plowing is a practice that involves plowing fields along the curves of a slope