1. Sedimentary Rock

2. What are sediments?
How do we get sediments?
How do these sediments become rocks?

3. Weathering and Erosion

4. Mechanical Weathering
Physical disintegration ~ breaking into smaller pieces.
Plants, animals,
water freezing cause mechanical weathering

5. Mechanical weathering

6. Chemical Weathering Rain water, acid, plant decay
Oxidation and carbonic acid cause chemical weathering

7. Climate and weathering
Warm climates favor chemical weathering.
The warmer the climate the faster the chemical weathering occurs.

8. Which type of weathering is this?

9. Erosion Moving of materials from point A to point B
Waves, streams, gravity, wind, glaciers cause erosion

11. Made from sediments
Sediments are formed from the breaking up of a parent rock.
The size and shape of the sediment tells how and where that rock was created.

12. Sedimentary Rock Formation
Step 1: Derive a sediment via weathering or erosion from a parent rock.
Step 2: Lithify the sediment
You have a sedimentary rock!

13. Two Stages of Lithification
Compaction
grains are compressed together due to an overlying weight
Cementation
minerals invade pore spaces between sediments and solidify

15. Three types of sedimentary rocks
1. Clastic ~ from sediments (sandstone)
2. Organic ~ from organisms
(fossil limestone)
3. Chemical ~ from minerals left by evaporation (halite)

16. Detrital Sedimentary Rocks
Clastic sediments = loose fragments of pre-existing rocks or minerals formed weathering
Classified by grain size, shape, sorting, and composition

17. Chemical Sedimentary Rocks
Minerals precipitate out of solution
May appear crystalline
Classified by composition
Rock Salt
Biochemical Limestone

18. Depositional Environment
Depositional Environment: A locality in which sediment is deposited by a depositional agent, including wind, water, ice, and gravity
Observations of these environments in the rock record can used to identify ancient conditions

19. Review Questions What are the three types of sedimentary rocks?
What is the difference between compacting and cementing?