1. Sedimentary Rocks

2. Made from sediments or rock material that has been broken down in some way.
Sedimentary rocks are usually formed in a watery environment.
Often layered
Are the only rocks that contain fossils

3. What Processes Form Sedimentary Rocks? ESRT

4. Principle of Superposition:
As sediments are deposited they go through compaction and cementation also called lithification where the sediments become solid rock
Newer sediments deposit over older sediments and thus the newest rocks are on top and oldest deeper down

5. Why are sedimentary rocks found in the upper layers of the crust?
This forms a VENEER (thin layer) over much of the igneous and metamorphic rocks on earth as they are made of weathered sediments, organic material, or residuals of evaporated water (evaporites) that form on land’s surface or below water (lakes, oceans, rivers…)

6. Sedimentary rock forms in upper crust- oceanic and continental!

7. Types of Sedimentary Rocks
Clastic (fragmental) –made by compaction and cementation of sediments.
Clastic rocks are identified by the size of the fragments.

8. Mixed

9. Conglomerate has rounded fragments

10. Breccia has angular fragments

11. Some Common Sedimentary Rocks: Sandstone; Gritty feeling, may identify layering, looks like…sand!

12. Shale: fine grained, flaky looking, can be layered and have iron oxides

13. Chemically formed rocks: #1 Crystalline (made of intergrown crytals)
Formed when water carrying minerals evaporates and leaves the minerals behind-called evaporites
Are identified by the minerals present (ie halite hardness of 2.5)

15. Halite/Rock Salt Deposits- formed from evaporating water leaving salts behind!

16. Crystalline Limestone: A precipitate
Sea water becomes supersaturated with calcium carbonate, which comes out of solution on seed particles (particles in sea water) and deposits on ocean floor.

17. Chemically Formed #2: Bioclastic
bio= life
clastic= fragments
Made from accumulated shells (limestone) or plants (coal)

19. Bioclastic Coquina (fossilized limestone)

20. Cyrstalline limestone vs. coquina limestone

21. Coal: