1. Rocks that are formed in flat layers called strata
Sedimentary Rocks
Rocks that are formed in flat layers called strata

2. Sedimentary Rocks Can Be Divided into Three Categories
CLASTIC
CHEMICAL
ORGANIC

3. CLASTIC SEDIMENTARY ROCK
When sediments are deposited, they settle to the bottom based on particle size. This is called stratification. These layers are called strata.

4. Classification of Clastic Rocks
Clastic sedimentary rocks are not classified by mineral composition
They are classified by the SIZE and SHAPE of the particles of sediment

5. Compaction and Cementation
As layers build up, the particles get pressed together. Water is squeezed out and the particles are cemented together by minerals

6. Clastic Sedimentary Rocks Examples
Shale
Made of mud and silt particles
Often breaks off in flat sheets

7. Clastic Sedimentary Rocks Examples
Sandstone
Made of sand particles cemented together
Different colors based on type sand particles

8. Clastic Sedimentary Rocks Examples
Conglomerate
Made of pebbles or rounded stones
Looks like natural concrete

9. Organic Sedimentary Rocks
Formed from the remains of living things
Shells of sea creatures
Dinosaur/ancient creature remains
Decayed plant material

10. Organic Sedimentary Rock Examples
Bituminous Coal
Made from the remains of decayed plant material
Used as a fossil fuel mostly for making electricity

11. Fossiliferous Limestone
Formed from the remains of sea creatures cemented together
Contains the mineral calcite (calcium carbonate)

12. Organic Sedimentary Rock Examples
Chalk
Made from the remains of microscopic organisms
First used on chalkboards

13. Chemical Sedimentary Rocks
Formed from dissolved minerals in water
When water evaporates, the minerals are left behind and crystallize
Most common places to find this:
Where ancient seas evaporated
Caves

14. Chemical Sedimentary Rock Examples
Limestone
Contains calcite
Can form stalactites and stalagmites in caves

15. Chemical Sedimentary Rock Examples
Halite
also known as rock salt
Forms when ocean water evaporates