S Flashcards
What is weathering?
Weathering refers to the natural process that breaks down rocks and minerals at or near the Earth’s surface.
Weathering plays a crucial role in shaping landscapes and forming soil.
What are the main types of weathering?
- Physical (Mechanical) Weathering
- Chemical Weathering
- Biological Weathering
Each type has distinct processes and agents.
Define physical (mechanical) weathering.
Breakdown of rocks without chemical changes.
It includes processes such as freeze-thaw cycles, thermal expansion, pressure release, and abrasion.
What is the main agent of freeze-thaw cycles in physical weathering?
Water enters cracks, freezes, and expands, causing the rock to break apart.
This process is also known as frost wedging.
What causes thermal expansion in rocks?
Repeated heating and cooling causes rock to expand and contract, leading to cracking.
This is a form of physical weathering.
What is exfoliation in the context of weathering?
Rocks formed under pressure expand and crack when exposed.
This is a type of physical weathering.
What is abrasion in weathering?
Rocks are worn down by wind, water, or ice carrying particles.
This is also classified under physical weathering.
What does chemical weathering involve?
Chemical changes in minerals within rocks.
This process alters the chemical composition of the rocks.
What is oxidation in chemical weathering?
Reaction of oxygen with minerals, e.g., iron-rich rocks rusting.
Oxidation is a significant process in chemical weathering.
What is hydrolysis in weathering?
Water reacts with minerals, forming new minerals and dissolving others.
Hydrolysis is a common process in chemical weathering.
What is carbonation in weathering?
Carbon dioxide in water forms carbonic acid, which dissolves carbonate rocks like limestone.
This process is significant for limestone weathering.
What is the solution process in chemical weathering?
Soluble minerals dissolve in water.
This process can lead to significant changes in rock formations.
What causes biological weathering?
Plants, animals, and microorganisms.
Biological weathering involves living organisms contributing to the breakdown of rocks.
Give an example of biological weathering.
Tree roots growing into cracks in rocks, causing them to split.
Other examples include lichens and burrowing animals.
How does climate affect weathering?
Physical weathering dominates in cold, dry climates; chemical weathering is more prevalent in warm, wet climates.
Climate significantly influences the type of weathering that occurs.
How does rock type and composition affect weathering?
Some rocks, like limestone, are more prone to chemical weathering; harder rocks resist weathering more than softer rocks.
The mineral composition of rocks plays a crucial role.
What is the relationship between surface area and weathering?
Smaller pieces weather faster due to a larger surface area relative to volume.
Increased surface area accelerates the weathering process.
How does topography influence weathering?
Steep slopes increase physical weathering due to erosion and gravity; flat areas promote chemical weathering by retaining water.
The landscape’s shape affects the type and rate of weathering.
