1. Formation of Sedimentary Rock!
Forces of Erosion
and
Types of Weathering

2. Sedimentary Rock Formation (Exploring Earth: Visualizations – How sediments are deposited)
Sedimentary Rock Formation Clip!

3. Weathering The Process of breaking down rocks and minerals into small pieces.
Mechanical Weathering – breaks rocks into smaller pieces but does not change the chemical composition of the rock.
Temperature Changes
Freezing Water
Root Action
Animal Activity
Abrasion from water/wind
Exfoliation/Release of pressure

4. Types of Weathering Physical/Mechanical – Temperature Changes!
Heat makes most things expand, while cool makes most things contract. Temperature changes during the day and night cause rocks to crack over time

5. Types of Weathering Physical/Mechanical – Freezing Water!
Water expands when it freezes. So, water in the cracks of rocks expands and cracks the rock more when it freezes.
Water can penetrate into cracks and when it freezes the water expands. The rock cracks a little more each time this happens.

6. Types of Weathering Physical/Mechanical – Root Action!
Trees and shrub have roots that can grow into cracks of rocks. Growing roots are very strong and can split rocks.

7. Types of Weathering Physical/Mechanical – Animal Action!
Animals don’t break rocks by digging. But, they dig into the ground allowing both air and water to cause weathering of rocks under the ground.

8. Types of Weathering Physical/Mechanical – Abrasion from running water/wind
Both wind and water can act like sandpaper and cause physical weathering of rock.

9. Types of Weathering Physical/Mechanical – Exfoliation/Pressure Release
A process where the outer layer of rock peels away. Rock underneath experience a decrease in pressure and expands causing more cracking.

10. Weathering
Chemical Weathering - breaks rocks into smaller pieces and changes the chemical composition of the rock.
Oxygen (oxidation)
Water
Carbon Dioxide

11. Types of Weathering Chemical – Carbon Dioxide!
CO2 combines with rain water to form Carbonic Acid (or acid rain). This “acid rain” can dissolve some types of rock such as limestone.

12. Types of Weathering Chemical – Water!
Water can change minerals in 2 ways.
It dissolves some minerals out of rocks making them brittle and easily broken.
Water combines with other substances to form new molecules and can easily break away from the rock.

13. Types of Weathering Chemical – Oxygen!
Oxygen can combine with other minerals to form oxides. The rock is now chemically changed and can break away from the original rock.
Rust!

14. Erosion
The process of moving rocks and minerals.
Wind
Water
Ice

15. Forces of Erosion WIND!
Wind can smooth and break rocks into smaller pieces and can move them to be deposited in another place.

16. Forces of Erosion Water!
Water can smooth and break rocks into smaller pieces and can move them to be deposited in another place.

17. Forces of Erosion Glaciers!
Large ice masses can smooth and break rocks into smaller pieces and move them to be deposited in another place when the ice melts.

18. Weathering and Erosion
Weathering breaks rocks into _________ and those _________ are carried away by the processes of ______.
________can be cemented or compacted over time to form this type of rock _________________________
sediments
sediments
erosion
Sediments
Sedimentary Rock