Weathering Flashcards
What is weathering?
The break up and decomposition of rock in their place of origin
What are the 3 categories of weathering?
Chemical, physical, biological
What is chemical weathering?
The break down of rocks caused by a change in their chemical structure
What is physical weathering?
The break down of rocks caused by physical processes. No change in chemical structure
What is biological weathering?
Sometimes included in physical weathering. When flora and fauna break down rocks
What are the types of chemical weathering?
Solution, hydrolysis, hydration and oxidation
What is solution (Chemical weathering)?
The carbonic acid in rainwater reacts with rocks like limestone and slowly dissolves them. Dissolved rock then gets washed away
What is hydrolysis (Chemical weathering)?
Hydrogen in rainwater reacts with minerals in rocks but combines with them
What is hydration (Chemical weathering)?
Certain rocks absorb water in their structure causing them to get bigger
What is oxidation (Chemical weathering)?
When the iron in the rock reacts with oxygen
What are the types of physical weathering?
Freeze-thaw, exfoliation, pressure release, salt crystal growth
What is freeze-thaw (Physical weathering)?
The water inside cracks freeze and expand placing pressure on the rock. This repeats and it cracks
What is exfoliation (Physical weathering)?
Rock heats up and expands in the day and cools down and contracts at night. This weakens the layers of the rock causing it to peel
What is pressure release (Physical weathering)?
The removal of pressure allows the rock to expand causing them to fracture
What is salt crystal growth (Physical weathering)?
Water is evaporated leaving salt crystals. The salt attacks rocks chemically or places pressure on structure
