Rocks & Weathering Flashcards
What are the types of weathering?
Physical
Biological
Chemical
What is weathering?
Weathering is the breakdown of rocks into smaller fragments. This happens because of change sin the environment.
What is freeze - thawing?
- Water expands as ice and exerts force onto surrounding rocks
- this happens over and over again
- This creates cracks in the rock eventually
- A fragment of rock will eventually fall off
PHYSICAL
What is exfoliation?
- The sun heats surface of rocks, rock expands
- night cools and rocks contract
- Flakes fall off
PHYSICAL
What is biological weathering?
PLants grow in the cracks of a rock?
What is slow chemical weathering?
Rainwater is naturally acidic, the weak acid slowly reacts with minerals in rock to wear it down.
What is rapid chemical weathering?
Rainwater becomes more acidic because of burning of fossil fuels like sulphur and nitrogen. This reacts with minerals more rapidly.
What is transportation?
Transportation is the movement of rock fragments from one place to another.
What is deposition?
When weathered rock sinks to the bottom of a river to form sediment.