Weathering, Soil, and Erosion

Weathering

is the breaking down and changing of rocks due to exposure to the environment.

Mechanical Weathering

• Mechanical weathering is the breakdown of rocks into sediments without changing their composition.
• Mechanical Weathering Types: Frost Action, Exfoliation, Abrasion, and Root Wedging.

Chemical Weathering

• the altering of rocks as a result of exposure to different substances
• Types: Oxidation, Hydrolysis, and Carbonation.

Soil

• It is where the atmosphere, hydrosphere, biosphere, and lithosphere meet.
• Important reactions between solid rock, liquid water, air, and living things occur within the soil layer.
• Soil is a complex mixture of different materials.
• About half of most soils are inorganic materials.
• About half of all soils are organic materials. Organic materials are necessary for a ground to be fertile. The organic portion provides the nutrients needed for vigorous plant growth, such as nitrogen.
• In soil, there are tiny spaces between the solid pieces filled with air and water.
• Soil is considered a renewable resource. However, the rate of being renewed is much slower than consumption and removal.
• Soil is used for vegetation, planting other valuable organic resources, and maintaining healthy ecosystems and a clean and safe environment.
• Simply, soils are a mixture of very important rock and mineral sediments and organic materials and, like any material, can go through erosion.

Factors that Determine Soil Type

• Slope
• Time
• Biological Activity

Climate

• It is the most critical factor in determining soil type because, given enough time, different rock types in a given climate will produce a similar soil.
• Even the same rock type in different climates will not produce the same soil type.
• more rain equals more chemical reactions to weather minerals and rocks
• increased rainfall increases the amount of rock that is dissolved as well as the amount of material that is carried away by moving water
• Increased temperature increases the rate of chemical reactions.

Rock Type

• the original rock is the source of the inorganic portion of the soil. The minerals that are present in the rock determine the composition of the material that is available to make soil.

Erosion

• Erosion is the transportation of sediments that have been broken down by weathering processes.
• The act of carrying sediments to a different location
• Agents: Water, Wind, Wave, Glacial, and Gravity

Water Erosion

water travels from points of lower concentrations to higher concentrations along with it, it can bring rocks and minerals of varying sizes depending on its strength.

Wave Erosion

• as waves continuously hit rocks and shores, it carries along with the sediments of sand and other rocks
• its continuous movement allows rocks to move through different parts of the ocean exposing the stones to different environments

Wind Erosion

• Strong gusts of wind can carry small particles of clay, sand, or silt and suspend them in the atmosphere for a given amount of time
• Wind erosion is mostly observed in and places as compared to humid environments

Glacial Erosion

when big chunks of glaciers slide along a mountain’s side, it can bring rocks and cause it to grind with others.

Gravity

Contributing factors to mudslides and landslides

• water
• rock types
• undercutting
• deforestation