1. Sediment and Sedimentary Rocks
Physical Geology

2. Sedimentary Rocks This is the most common rock type on Earth’s surface
Weathering creates sediment, ready to be transported
This is made up of derived from pre-existing rocks
We have two types of sediments:
Detrital
Chemical

3. Formation
Weathering
Erosion
Transport
Deposition
Lithification

4. Sedimentary Rocks Transportation
Running water, wind, glaciers, waves, currents all are transportation methods of sediments
Transportation can involve suspension as well as ions being dissolved in solution
Typically, the longer the transport process, the more rounded the sediment

5. Sedimentary Rocks Depositional Environments: Terrestrial Transitional
Marine

6. Depositional Environments
Terrestrial or Non-Marine
Soils
Lakes (fresh water, fine sediments)
Glacial (Poorly sorted, angular)
River/Fluvial (wide variety)

7. Depositional Environments
Transitional
Beach
Barrier islands
Deltas
Organic reefs

8. Depositional Environments
Marine
Shelf (coarser to finer as you move farther from shore)
Continental slope
Abyss (turbidity currents, graded bedding)

9. Lithification Sediments form sedimentary rocks through lithification
Compaction
Weight of overburden reduces porosity
Cementation
Chemical precipitation of minerals in pores (cement)
Examples:
Calcium carbonate
Silica
Pyrite

10. Types of Sedimentary Rocks
Detrital
Consists of particles (detritus) of rocks
Also referred to as clastic texture
Classified “primarily” by size
Gravel > 2mm
Sand 2mm-1/16mm
Mud rocks
Silt 1/16 – 1/256 mm
Clay < 1/256 mm

11. Types of Sedimentary Rocks
Classification can be by shape:
The more weathering and transportation a particle undergoes, the more rounded the particle
Classification can also be by composition:
How much of a specific mineral is present

12. Type of Sedimentary Rocks
Gravel:
Conglomerate (rounded gravel)
Breccia (angular breccia)

13. Type of Sedimentary Rocks
Sand:
Sandstone
Arkose (mixed variety of sand-sized particles)

14. Type of Sedimentary Rocks
Silt:
Siltstone
Clay:
Shale

15. Types of Sedimentary Rocks
Chemical Sedimentary Rocks
Formed by chemical precipitation from solution
Biochemical
There is an organism involved with the production of biochemical rocks.
Evaporites
Inorganic chemical precipitates

16. Types of Sedimentary Rocks
Biochemical:
Examples: limestone, chert, coal

17. Types of Sedimentary Rocks
Evaporates:
Rock gypsum, rock salt

18. Sedimentary Resources
Sand and gravel are used in construction
Clay is used for ceramics
Evaporties are used for salt and sheet rock
Coal is an important fuel source
Placer deposits  where we can look for minerals like gold and diamonds