1. Sedimentary Rock Formation

2. Formation Pre-existing rocks must be broken down Sediments: bits & pieces of pre-existing rock 2 general ways for this to happen 1.Weathering: break down of rocks in place 2.Erosion: break down and transport of rocks

3. Weathering Rocks must be exposed to the surface 2 forms 1.Chemical: rocks are chemically altered 2.Physical: rocks simply broken into smaller pieces Clasts: rock fragments produced from weathering

4. Chemical weathering

5. Physical Weathering

6. Erosion After rocks are broken down they must be transported 4 general means of transport 1.Wind 2.Moving water 3.Glaciers 4.Gravity Sediment is almost always carried downhill

7. Deposition When the agent of erosion loses energy (slows down/stops) sediment is dropped or deposited

8. Sediment Transport & Settling Sediment is transported farther distances due to 2 factors 1. Clast size 2. How much power the agent of transport has  As particles settle out the larger ones are dropped first  Therefore sediments are usually sorted by size (exception: glaciers)

9. Lithification Process Lithos: Stone in Greek Lithify: rock making process 3 Steps 1. Deposition: Sediment is deposited in basins or natural bowls 2. Compaction: Weight of overlying layers pile up increasing pressure & temp. 3. Cementation: Dissolved minerals act as glue when they solidify, cementing grains together  Ex/ calcite, iron oxide, & silica

10. Sedimentary Features Bedding: sediments are deposited in horizontal layers Graded Bedding: clast size gets bigger towards the bottom Cross-bedding: inclined layers of sediment (ex/ sand dunes)

11. Bedding

12. Bedding

13. Cross-bedding & Ripple Marks

14. Fossils Remains of once living organisms  Can be parts of the organism, imprints, or actual remains  Preservation of bones (other hard parts) is called mineralization –Process where organic material replaced by dissolved minerals

15. Classifying sedimentary rocks Two groups based on source material 1. Detrital/Clastic rocks Solid particles classified by size Gravel (>2mm in size) Sand (1/16th – 2mm in size) Silt (1/256th – 1/16th mm in size) Mud (less than 1/256th mm in size) Common rocks include Conglomerate Sandstone Siltstone Shale (most abundant clastic)

16. Classification of sedimentary rocks

17. Shale with plant fossils

18. Conglomerate

19. Classifying sedimentary rocks 2. Chemical rocks Formed from material once dissolved in solution 2 types based on formation: 1. E vaporation: liquid evaporates & solid deposited on the bottom 2. O rganic: Through life processes (biochemical origin)

20. Sedimentary rocks Common chemical sedimentary rocks Limestone – the most abundant chemical rock Microcrystalline quartz (precipitated quartz) known as chert, flint, jasper, or agate Evaporites such as rock salt or gypsum Coal

21. Fossiliferous limestone Fossiliferous limestone

22. Rock salt