O Lecture 10/15/10

  1. Where do sediments come from?
    space, eriosion, weather
  2. What are marine sediments
    • eroded rock particles and fragments
    • transported to ocean
    • deposit by settling through water column
    • oceanographers decipher earths history through studying sediments
  3. What the two types of weather
    • Physical weather
    • chemical weather
  4. weathering
    breakdown of rocks, soils, and minerals through direct contact with the planet's atmosphere
  5. Some components of physical weathering
    heat, water, ice, and pressure
  6. What is physical weathering?
    • physical breakdown of rock
    • makes small chunks and higher surface area
  7. some components of chemical weathering
    soil pH, temperature, precipitation, composition of rock
  8. Trees help chemical weathering
    H2O + CO2 -> Ca2+ + 2HCO3-
  9. What are the two types of chemical weathering?
    • congruent
    • Incongruent
  10. Congruent Chemical weathering
    results in only dissolved ions
  11. Incongruent Chemical Weathering
    results in newly made clay minerals and dissolved ions
  12. Example of congruent chemical weathering
    • limestone weathering
    • CaCO3 + H2O + CO2 -> Ca2+ +2HCO3-
  13. Example of Incongruent weathering
    2NaAlSi3O8 + 11H2O + 2CO2 -> 2Na+ + 2HCO3- + 4H4SiO4 + Al2Si2O5(OH)4
  14. What is the size of particulate matter?
    larger than .45 microns
  15. What is the size of dissolved matter?
    below .45 microns
  16. How is marine sediment classified?
    By origin
  17. What are the classifications of marine sediment?
    • Terrigenous or ithgenous
    • Biogenous
    • Hydrogenous (aka Authigenic)
    • Cosmogenous
    • volcanogenous
  18. Cosmogenous Marine Sediment
    • macroscopic meteor debris
    • overall insignificant proportion of marine sediment
  19. Hydrogenous Marine Sediment
    near hydrothermal vents, lots of metal ions are released intot he water and these ions oxidize or combine with silica and precipitate out as dark, metal rich sediment
  20. Volcanogenous marine sediment
    • comes from volcanoes
    • distributed in the marine realm by wind, streams, submarine gravity
  21. Terrigenous sedimetns
    • most lithogenous sediments at continental margins
    • coarser sediments closer to shore
    • finer sediments farther from shore
    • mainly mineral quartz
    • erroded rock fragments from land
    • agents of transport - water, wind, ice, gravity
  22. wind as an agent of transport
  23. Biogenous marine sediments
    • hard remains of once-living organisms
    • macroscopic
    • microscopic
  24. Biogenic ooze
    30% more or more tests
  25. Silica
  26. diatoms
  27. Coccoliths
    calcium carbonate
  28. calcium carbonate
  29. factors controlling distribution of biogenous sedimetns
    • productivity
    • destruction (dissolution)
    • dilution
Card Set
O Lecture 10/15/10