1. Sedimentary Rocks Sediments Lithification Deposition Transport Erosion
Weathering

2. From Sediment to Rock
Most sedimentary rocks are formed through a series of processes: erosion, deposition, compaction, and cementation.

3. Weathering Mechanical & Chemical Weathering
The sediments that make up sedimentary rocks are produced by:
Mechanical & Chemical Weathering

4. Mechanical Weathering

5. Chemical Weathering

6. Mineral Stability

7. Products of Weathering
Lithic (Rock) Fragments (granite, basalt, schist, etc.)
Dissolved Ions (Calcium, Potassium, Sodium, etc.)
Rust Minerals (Hematite, Goertite, etc.)
Clay Minerals (Bentonite, Montmorillonite, etc.)
Residual Minerals (Quartz, Orthoclase, Muscovite, etc.)

8. Erosion & Transport
Water
Wind
Ice
Gravity

9. Deposition

10. Lithification
Sediment
Rock

11. Cementation
Typical Cement:
Calcite
Quartz

12. Sedimentary Rocks Identification Note: Use the same terms to describe
sediments & sedimentary rocks.
Only difference is lithification!

13. Rock Identification is based on:
Composition What minerals make up the rock?
Texture What is the shape, size and orientation of the mineral grains that make up the rock? Major Difference: Crystalline vs. Clastic

14. Types of Sedimentary Rocks
Detrital Rocks
Chemical Rocks
vs.

15. Difference: Texture Detrital (Clastic Texture) vs
Difference: Texture Detrital (Clastic Texture) vs. Chemical (Crystalline Texture)

16. Detrital Rock Composition
Detrital Rocks
Lithic Fragments
Quartz
Clay Minerals
Fossil Fragments
Rust Minerals
Orthoclase
Muscovite / Biotite

17. Detrital Rock Texture Clastic Texture Grain Size Grain Sorting
Grain Rounding
Sediment Maturity

18. Grain Size
Gravel 2mm
Sand 1/16 mm
Mud - Silt 1/256 mm
Mud - Clay

19. Detrital Rock Names (Based Primarily on Grain Size)
Gravel Sized:
Conglomerate
Sand Sized: Sandstone
Mud Sized:
Mudstone
Siltstone
Shale

20. Sorting

21. Grain Roundness

22. Gravel Sized Detrital Rocks (Subdivided Based on Grain Roundness)
Conglomerate
Breccia

23. Maturity Immature Mature Well Sorted Poorly Sorted Well Rounded
All Quartz
Immature
Poorly Sorted
Angular grains
Mixed Composition including clay

24. Sandstones (Subdivided based on maturity)
Quartz Sandstone
Arkose (Sandstone)
Lithic Sandstone
Sandstones (Subdivided based on maturity)
Greywacke

25. Sandstones Under a Scope

26. Detrital Sedimentary Rock ID

27. Chemical Rock Texture
Crystalline Texture
Coarse
Fine

28. Chemical Sedimentary Rocks (Names based primarily on composition)
Calcite
Quartz (silica)
Halite
Gypsum
“Carbon” / Plant Remains
Basic Rock Name
Limestone
Chert
Rock Salt
Rock Gypsum
Peat or Coal

29. Chemical Rocks (Names based mainly on composition)
Crystalline
Limestone
Limestones
Fossiliferous Limestone
Chalk

30. Chemical Rocks (cont.)
Evaportites
Chert
Rock Salt
Rock
Gypsum
Coal

31. Chemical Sedimentary Rock ID

32. Sedimentary Rocks on Earth