Chapter 9 Section 1 Weathering And Soil Formation Flashcards
What is mechanical weathering?
Mechanical weathering is the process by which rocks break down into smaller pieces by physical means.
What is weathering?
The natural process by which atmospheric and environmental agents such as wind, rain, and temperature changes, disintegrate in decompose rocks.
What is frost action?
One cause of mechanical weathering is frost action the alternate freezing and thawing of soil and rock
What is ice wedging?
Ice wedging is when water gets into cracks, freezes and expands the crack over and over again
What is abrasion?
The grinding and wearing away of rock surfaces through the mechanical action of other rock or sand particles.
How can sediment transported in a stream cause abrasion?
Sediment contains tiny rocks, which cause abrasion is they bump into other rocks as they are transported by the river.
What is exfoliation?
A process by which sheets of rock peel away from a large body of rock because pressure is removed.
How does plant growth cause mechanical weathering?
Plant roots grow into cracks, and expand the cracks until the rocks break
How can animals cause mechanical weathering?
Their motion brakes particles into smaller particles and exposes fresh surfaces to continued weathering.
What is chemical weathering?
The process by which rocks breakdown as a result of chemical reactions.
What are some common agents of chemical weathering?
Water, acids, and air.
What is acid precipitation?.
Rain, sleet, or snow that contains high concentrations of acids called a acid precipitation.
What causes acid precipitation?
Natural sources such as volcanoes as well as air pollution from burning fossil fuels causes acid precipitation.
What does acid precipitation do to rock?
Because acids are more reactive than regular water acid precipitation can cause very rapid weathering of rock.
How do living things add to the chemical weathering of rock?
All living things make that in their bodies. Acids in the water break down the rock.
What is oxidation?
Oxidation is a chemical reaction in which an element such as iron combines with oxygen to form an oxide.
List three causes of chemical weathering of rocks.
Water dissolve some of the chemicals that make up the rock. Acids react with chemicals to break down the rock. Oxygen in the air causes oxidation of the rock to form oxides.
Describe three ways abrasion occurs in nature.
Water can cause abrasion as rocks bump into one another in water. When causes abrasion by blowing sand against a rock. Gravity causes abrasion by causing rocks to grind against one another as they slide down the hill.
