1. Chapter 14: Marine Sediments
Chapter 14 notes…
Do page 1 (questions) LAST
*page 2: Sediment types (where do they come from)
*page 3: Location: shelf vs. deep ocean

2. Chapter 14: Marine Sediments
Fig. 5-23

3. Marine Sediments
Fig. CO-4

4. Sediments reveal Earth history
Sediments lithified
Mineral composition
Sedimentary texture
Past climate
Plate motions
Age of seafloor
Fossil evolution and extinction

5. Sediments classified by origin
Lithogenous (Land)
Biogenous (Life)
Hydrogenous (Water)
Cosmogenous (Space)

6. Lithogenous sediments
Fig. 4.5

7. Lithogenous/ Terrogenous sediments
Rock fragments from land
Transported to oceans by
Rivers
Wind
Ice
Gravity flows (e.g. turbidity currents)

8. Rivers transport much sediment
Fig. 5-5

9. Biogenous sediments Hard parts of once-living organisms
Shells, teeth, bones
Fig. 5-10

10. Biogenous marine sediments
Commonly either calcium carbonate (CaCO3) or silica (SiO2 or SiO2·nH2O - opal)
Usually planktonic (free-floating)

11. Biogenous sediments Calcareous ooze (CaCO3) Siliceous ooze (SiO2)
Microscopic protozoans, foraminifera
Microscopic algae, coccolithophores
Siliceous ooze (SiO2)
Microscopic protozoans, Radiolaria
Microscopic algae, diatoms

12. Calcium carbonate in biogenous sediments
Coccolithophores (algae)
Photosynthetic
Coccoliths (nano-plankton)
Rock chalk
Fig. 4.8a

13. Calcium carbonate in biogenous sediments
Foraminifera (protozoans)
Use external food
Calcareous ooze
Fig. 4.8c

14. Carbonate deposits Limestone (lithified carbonate sediments)
Stromatolites
Warm, shallow-ocean, high salinity
Cyanobacteria
Exist in hypersaline tidal pools – Hamelin Pool in Shark Bay, Australia and Eleuthra Bank, Bahamas
Fig. 4.10a

15. Distribution of calcareous oozes in surface sediments of modern sea floor
Fig. 4.14

16. Silica in biogenic sediments
Diatoms (algae)
Photosynthetic
Diatomaceous earth
Radiolarians (protozoans)
Use external food
Siliceous ooze
Fig. 4.7a
Fig. 4.7b

17. Siliceous ooze Seawater undersaturated with silica
Fig. 4.11
Seawater undersaturated with silica
Siliceous ooze commonly associated with high biologic productivity in surface ocean

18. Hydrogenous marine sediments
Minerals precipitate directly from seawater
Manganese nodules
Evaporites
Inorganic Carbonates
Metal sulfides
Small proportion of marine sediments
Distributed in diverse environments

19. Manganese nodules Very low rate of accumulation
Fig. 4.15a
Manganese nodules
Very low rate of accumulation
Larger nodules grow larger faster
Origin is unknown

20. Cosmogenous sediments
Extraterrestrial fragments
Extra = outside
Terr = Earth
ial = makes the word an adjective
Glassy tektites
Fe-Ni micrometeorites
Found in deep ocean where other sediments accumulate very slowly

21. Meteorite impact K-T meteorite crater off Yucatan peninsula
Tektites and spherules found in marine seds
Shocked quartz in marine seds
Fig. 5D

22. TO DO Finish remaining Ch. 14 Notes Sediments Analysis Prelab
Lab next class! 