EARTH AND ROCKS - Sedimentary rocks Flashcards
(15 cards)
What are the 3 types of rocks?
- Sedimentary rocks
- Igneous rocks
- Metamorphic rocks
What are the properties of rocks?
- Made of separate grains
- Porous
- Soft
What does it mean to call sedimentary rocks porous?
There are gaps between the grains.
What are the steps by which sedimentary rocks are formed?
- Weathering
- Erosion and Transport
- Deposition
- Compaction/Cementation
What are the 3 types of weathering?
- Physical weathering
- Chemical weathering
- Biological weathering
Give an example of Physical weathering.
Freeze-thaw weathering
Describe the process of Freeze-thaw weathering.
- Water enters the cracks of rocks.
- At night or when the temperatures drop, the water freezes.
- Ice is formed and takes up more space than water.
- It pushes against the side of the crack.
- Over several times, the crack gets larger and eventually the rock breaks.
What is Chemical weathering?
- Rain falls on rocks
- Acids in the rain react with the rock, wearing it down
What is Biological weathering?
When plants or animals break rocks.
What is erosion?
The entire process of weathering and sediments being transported away.
How are sediments transported?
Many ways:
1. Water
2. Ice
3. Wind
4. Gravity
What is Deposition?
When sediments settle in one place, they form layers of sediments.
What is compaction?
The weight of sediments above squashes together the sediments below.
What is cementation?
Another substance sticks the sediments together.
How are sedimentary rocks useful?
- They can be used to make attractive architecture.
- They can be used on pavements/roads to absorb rain water and avoid a slippery ground.
