Sedimentary rocks form through the compaction and cementation of sediments. There are three main types: clastic rocks like shale and sandstone form from fragments of pre-existing rocks; chemical rocks like rock salt form through precipitation from solution; and organic rocks like coal form from the remains of plants and animals. Clastic rocks specifically form through the weathering of parent rocks, transportation of fragments by wind/water, deposition, and cementation as minerals fill the spaces between fragments.

1. Sedimentary rocks

2. sediment Solid fragments of inorganic or organic material from the weathering of rock are carried and deposited by wind, water, or ice.

3. Weathering is the decomposition of Earth's rocks, soils and minerals through direct contact with the planet's atmosphere.

4. 3 types of sedimentary rocks 1. clastic 2. chemical 3. organic

5. Sedimentary rocks 1. clastic rocks: formed from fragments of OTHER rocks. e.g. shale, sandstone, conglomerate 2. chemical 3. organic

6. shale Shale is a clastic sedimentary rock that is made up of clay-size (less then 1/256 millimeter in diameter) weathering debris. It typically breaks into thin flat pieces.

7. sandstone

8. conglomerate

9. 3 types of sedimentary rocks 1. clastic: shale, sandstone, conglomerate 2. chemical: sedimentary rocks formed when form when dissolved materials precipitate from solution (by evaporation or chemical action) E.g. rock salt, some limestones 3. organic

10. Rock salt (halite)

11. limestone

12. 3 types of sedimentary rocks 1. clastic: shale, sandstone, conglomerate 2. chemical: rock salt, some limestones 3. organic: formed from remains of plants and animals. E.g. some limestones, coal

13. limestones

14. Limestone forming environment a coral reef system from the Kerama Islands in the East China Sea southwest of Okinawa. Here the entire seafloor is covered by a wide variety of corals which produce calcium carbonate skeletons.

15. coal

16. coal forms from the accumulation and preservation of plant materials, usually in a swamp environment

17. 3 types of sedimentary rocks 1. clastic 2. chemical 3. organic How do clastic rocks form

18. Clastic rocks 1. Come from the weathering of other rocks. 2. From small to large fragments, ranging from pebbles to gravels to microscopic flakes. 3. Carried by winds, waves, and water. 4. sediments are deposited when a stream slows down.

19. Clastic rocks 5. IMPORTANT: Dissolved minerals like silica, calcite, and iron oxide act as cement, or glue. These minerals settle into the spaces between sand grains or pebbles, and bind the fragments.

20. Sorting of sediments

21. conglomerate

22. conglomerate Formed from pebbles, sand grains Quartz is the most common mineral. (it’s very durable)

23. sandstone

24. sandstone Formed largely from grains of quartz. Up to 30% of sandstones may be air space, making them porous and permeable.

25. shale

26. shale Formed from tiny clay flakes. (of mineral kaolin)

27. shale Smooth, soft, brittle