1. Other Resources Rare Earth elements
Assortment of 17 chemically similar metals
Used in technology, e.g., cell phones, television screens, etc.
Sea floor may hold more rare Earth element deposits than found on land

2. Petroleum Commonly called “oil”
Naturally occurring liquid made of hydrocarbons.
Oil spills – often from transport accidents
Some from extraction
2010 Gulf of Mexico Deepwater Horizon blowout
Some from loading/unloading accidents

3. Exxon Valdez Oil Spill March 29, 1989
Almost 44 million liters (11.6 million gallons) of oil spilled into Prince William Sound, AK
Many animals, including birds and otters, killed outright
Long-term consequences unknown

4. Exxon Valdez Oil Spill

5. Notable Oil Spills

6. Notable Oil Spills
Kuwait – intentional dumping of oil into Persian Gulf in 1991
More than 908 million liters (240 million gallons) spilled
20 times the amount of Exxon Valdez

7. Notable Oil Spills

8. Notable Oil Spills
Gulf of Mexico – 2010 explosion of Deepwater Horizon oil drilling platform
World’s largest accidental ocean oil spill
Spilled more than 780 million liters (206 million gallons)

9. Notable Oil Spills Ixtoc #1 Mexico spill
World’s largest spill from well until 2010
Took 10 months to cap
Spilled 530 million liters (140 million gallons)

10. Petroleum Made of various hydrocarbons
Contains hydrogen and carbon
Organic and can be biodegraded
Oil that enters ocean is result of small, frequent, widespread release of oil related to human consumption

11. Petroleum Toxic compounds in petroleum
Polycyclic aromatic hydrocarbons
Can sicken humans, animals, and plants in small doses
Can have long-term impacts on organisms
Change gene expression
Developmental abnormalities
Decreased embryo survival

12. Cleaning Oil Spills
Marine organism fur or feathers lose insulation properties when covered in oil
High fatality rates

13. Recovery of Organisms after Exxon Valdez Oil Spill

14. Oil in the Ocean Oil spills not primary source of ocean oil
Most petroleum in oceans from human activity
Small but frequent widespread oil releases

15. Cleaning Oil Spills Oil initially floats Can disperse Can be skimmed
Oil and water mix to form mousse

16. Cleaning Oil Spills
Bioremediation – use of bacteria and fungi to help clean oil spills
Releasing bacteria directly into marine environment
Creating conditions to stimulate growth of naturally occurring oil-degrading bacteria

17. Preventing Oil Spills Oil Pollution Act of 1990
Single-hulled tankers barred from U.S. ports, not allowed within 320 km (200 miles) of France and Spain
Double-hulled tankers
Redesigning ships

18. Preventing Oil Spills
Japanese-owned freighter New Carissa ran aground near Oregon
Intentionally burned to prevent larger oil spill

19. Chapter Overview Marine sediments contain a record of Earth history.
Marine sediments provide many important resources.
Marine sediments have origins from a variety of sources.

20. Marine Sediments Sediments
Eroded particles
Fragments of dust, dirt, other debris
Suspension settling – sediments settle out of water and accumulate on ocean floor.

21. Marine Sediments Provide clues to Earth history
Marine organism distribution
Ocean floor movements
Ocean circulation patterns
Climate change
Global extinction events

22. Marine Sediments Texture – size and shape of particles
Sediment origins
Worn rocks
Living organisms
Minerals dissolved in water
Outer space
Sediments lithify into sedimentary rock

23. Classification of Marine Sediments

24. Marine Sediment Collection
Early exploration used dredges.
Modern exploration
Cores – hollow steel tube collects sediment columns
Rotary drilling – collects deep ocean sediment cores

25. Marine Sediment Collection
National Science Foundation (NSF) – formed Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES) in 1963
Scripps Institution of Oceanography
Rosenstiel School of Atmospheric and Oceanic Studies
Lamont-Doherty Earth Observatory of Columbia University
Woods Hole Oceanographic Institution

26. Marine Sediment Collection
DSDP became Ocean Drilling Project (ODP) in 1983
JOIDES Resolution replaced Glomar Challenger
Integrated Ocean Drilling Program (IODP)
Replaced ODP in 2003
Chikyu – new exploration vessel in 2007
Expedition to Japan Trench after 2011 earthquake

27. Paleoceanography and Marine Sediments
Paleoceanography – study of how ocean, atmosphere, and land interactions have produced changes in ocean chemistry, circulation, biology, and climate

28. Paleoceanography and Marine Sediments
Marine sediments provide clues to past environmental conditions.
Cores of sediment collected from sea floor.

29. Examining Ocean Sediment Cores

30. Marine Sediment Classification
Classified by origin
Lithogenous – derived from land
Biogenous – derived from organisms
Hydrogenous or Authigenic – derived from water
Cosmogenous – derived from outer space

31. Lithogenous Sediments
Eroded rock fragments from land
Also called terrigenous
Reflect composition of rock from which derived
Produced by weathering
Breaking of rocks into smaller pieces

32. Lithogenous Sediments
Small particles eroded and transported
Carried to ocean
Streams
Wind
Glaciers
Gravity
Greatest quantity around continental margins

33. Lithogenous Sediment Transport Mechanisms

34. Lithogenous Sediments
Reflect composition of rock from which derived
Coarser sediments closer to shore
Finer sediments farther from shore
Mainly mineral quartz (SiO2)

35. Lithogenous Quartz and Wind Transport

36. Texture and Environment
Texture indicates environmental energy
High energy (strong wave action) – larger particles
Low energy – smaller particles
Larger particles closer to shore

37. Sediment Distribution
Neritic
Shallow-water deposits
Close to land
Dominantly lithogenous
Typically deposited quickly
Pelagic
Deeper-water deposits
Finer-grained sediments
Deposited slowly

38. Neritic Lithogenous Sediments
Beach deposits
Mainly wave-deposited quartz-rich sands
Continental shelf deposits
Relict sediments
Turbidite deposits
Graded bedding
Glacial deposits
High-latitude continental shelf
Currently forming by ice rafting

39. Pelagic Deposits Fine-grained material
Accumulates slowly on deep ocean floor
Pelagic lithogenous sediment from
Volcanic ash (volcanic eruptions)
Wind-blown dust
Fine-grained material transported by deep ocean currents

40. Pelagic Deposits Abyssal Clay
At least 70% clay sized particles from continents
Red clays from oxidized iron (Fe)
Abundant if other sediments absent

41. Biogenous Sediment Hard remains of once-living organisms
Two major types:
Macroscopic
Visible to naked eye
Shells, bones, teeth
Microscopic
Tiny shells or tests
Biogenic ooze
Mainly algae and protozoans

42. Biogenous Sediment Composition
Two most common chemical compounds:
Calcium carbonate (CaCO3)
Silica (SiO2 or SiO2·nH2O)

43. Silica in Biogenous Sediments
Diatoms
Photosynthetic algae
Diatomaceous earth
Radiolarians
Protozoans
Use external food

44. Silica in Biogenous Sediments
Tests – shells of microscopic organisms
Tests from diatoms and radiolarians generate siliceous ooze.

45. Diatomaceous Earth Siliceous ooze lithifies into diatomaceous earth.
Diatomaceous earth has many commercial uses.

46. Calcium Carbonate in Biogenic Sediments
Coccolithophores
Also called nannoplankton
Photosynthetic algae
Coccoliths – individual plates from dead organism

47. Calcium Carbonate in Biogenic Sediments
Rock chalk
Lithified coccolith-rich ooze
White Cliffs of southern England (Dover)

48. Calcium Carbonate in Biogenic Sediments

49. Calcium Carbonate in Biogenic Sediments
Foraminifera
Protozoans
Use external food
Calcareous ooze

50. Pelagic Deposits Siliceous ooze
Accumulates in areas of high productivity
Silica tests no longer dissolved by seawater when buried by other tests

51. Pelagic Deposits

52. Neritic Deposits
Dominated by lithogenous sediment, may contain biogenous sediment
Carbonate Deposits
Carbonate minerals containing CO3
Marine carbonates primarily limestone
CaCO3
Most limestones contain fossil shells
Suggests biogenous origin
Ancient marine carbonates constitute 25% of all sedimentary rocks on Earth.

53. Carbonate Deposits Stromatolites Lived billions of years ago
Fine layers of carbonate
Warm, shallow-ocean, high salinity
Cyanobacteria
Lived billions of years ago

54. Carbonate Deposits

55. Carbonate Deposits Stromatolites
Modern stromatolites live near Shark Bay, Australia

56. Calcareous Ooze CCD – Calcite compensation depth
Depth where CaCO3 readily dissolves
Rate of supply = rate at which the shells dissolve
Warm, shallow ocean saturated with calcium carbonate

57. Calcareous Ooze Cool, deep ocean undersaturated with calcium carbonate
Lysocline – depth at which a significant amount of CaCO3 begins to dissolve rapidly

58. Calcareous Ooze and the CCD
Scarce calcareous ooze below 5000 meters (16,400 feet) in modern ocean
Ancient calcareous oozes at greater depths if moved by sea floor spreading

59. Calcareous Ooze and the CCD

60. Sea Floor Spreading and Sediment Accumulation