Unit 5 Soil

What is mechanical weathering?
When physical forces breaks rock into smaller and smaller pieces without changing the rock’s mineral composition
What is frost wedging ?
The mechanical breakup of rock caused by the expansion of freezing water in cracks and crevices
When water freezes it volume ?
Its volume expands about 9 percent excerting outward force
Which of the following is not associated with mechanical weathering?
Reactions with oxygen
What is chemical weathering ?
Transformation of rock into one or more new compounds
Which of the following is the result of chemical weathering?
A rock that has been changed into one or more new compounds
The atmospheric gas that forms a mild acid when dissolved in water is ?
Carbon dioxide
What would cause the inscription on a marble gravestone to become harder are harder to read overtime ?
Chemical weathering
What climate does chemical weather favor the most?
Climates and high temperatures and abundant moisture’s
What are the major components of soil?
A soil’s texture is determined by?
Clay, silt, and sand int he soil
The main source of organic matter in soil is __.
plants
Use figure 5-1 to determine what a soil is called if it has 20 percent clay, 60 percent silt, and 20 percent sand
Silty loan
What are the proportions of clay, silt, and sand shown at point B in figure 5-1
Clay 20 percent , silt 40 percent , sand 30 percent
What are the proportions of clay, silt, and sand shown at point A in figure 5-1
clay 60 percent , silt 20 percent and sand 20 percent
What are the proportions of clay, silt and sand shown at point C in figure 5-1
clay 10 percent , silt 20 percent and sand 70 percent
A soil associated with the hot and wet tropics are ?
laterite
Pedalfer soils contain high amounts of?
Iron oxide and aluminum rich clays
The processes responsible for moving material downslope under the influence of gravity is called?
Mass movement
What is the force behind mass movements ?
Gravity
A mass movement that involves the sudden movement of a block of material along a flat, inclined surface is called the ___?
Slide,- Rock slides
Which of these factors affects the rate of weathering?
All of the above
Why can the removal of vegetation trigger mass movements ?
The plants roots behind the soil and regolith togeather
In the process of ________, water freezes and expands , enlarging cracks in rocks
Frost wedging
A large pile of debris that forms at the base of a slope is called?
Talus
What is the most important agent of chemical weathering?
Water
What is regolith?
Earth’s land surface
The forces that drives mass movements is ____?
Gravity
What is the content of the soil type Pedocal?
Abundant calcite or calcium carbonate and are typically light grey brown
What is the location and content of the soil type Laterite?
Found in hot, wet tropics areas
One of the most dramatic triggers of sudden mas movements is an?
____________, the slowest type of mass movements , involves the lifting and contracting of soil particles overtime
What are the three factors that affect the rate of weathering ?
Mechanical weathering rock characteristics and climates
How are soils classified based on texture?
You use the percentage of clay silt and sand
Explain the three processes that breaks rocks into smaller pieces during mechanical weathering ?
Frost wedging unloading and biological activity