1. Sedimentary RockStudents will be able toDescribe how rocks are formedClassify the sedimentary typesList uses for this rock type

2. Changing Earth’s Surface Weathering Physical breaking of rock Mass Wasting Falling due to gravity Erosion Removal by mobile agents (water, wind, ice…)

3. Weathering Frost Wedging Water expands 9% when frozen Repeated cycles will break apart rocks

4. Weathering Unloading When pressure is released by exposure Rock cracks in sheets when it expands

5. Weathering Biological Damage caused by roots and animals

6. Weathering Chemical Acid rain, pollution, …

7. Mass Wasting Spheroidal

8. Erosion Loss of material usually loose soil

9. Sedimentary Rock 5% of Earth’s outer crust High Value Contains major energy resources Contains fossil record

10. Formation Compaction Weight of material on top presses into rock Cementation Minerals enter spaces between to harden

11. Types Clastic Rock fragments squeezed together Organic Formed from remains of living things Chemical Formed from chemical during evaporation

12. Clastic Shale 50% of all sedimentary rock Made from tiny pieces of clay Black due to abundant carbon (living) Formed in oxygen poor area (swamp) “prevents decay”

13. Sandstone 20% of all sedimentary rock Small grains (wind or river)

14. Conglomerate Large particles Steep slopes or fast streams

15. Organic Limestone 10% of all sedimentary rock Mostly calcite Skeletons of coral reefs Accumulation of shells Caves from minerals above

16. Coal Many plant parts Low oxygen formation (swamp) High heat and pressure to solidify Major source of US electrical energy

17. Chemical Evaporites Seawater and salt flats evaporate

18. Quiz

19. Homework Describe how sedimentary rocks are made