Sediments in the ocean powerpoint

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  • Distribution of pelagic sedimentDominant component Composition Atlantic Pacific IndianTotal % Foraminiferal ooze and nannofossil oozeCalcium carbonate65 365447Pteropod ooze Calcium carbonate20.1- 0.5Diatom oozeSilica (opal)71020 12Radiolarian oozeSilica (opal)-50.53Red (actually brown) clay K, FeAl silicate26492538
  • Distribution of pelagic sedimentDominant component Composition Atlantic Pacific IndianTotal % Foraminiferal ooze and nannofossil oozeCalcium carbonate65 365447Pteropod ooze Calcium carbonate20.1- 0.5Diatom oozeSilica (opal)71020 12Radiolarian oozeSilica (opal)-50.53Red (actually brown) clay K, FeAl silicate26492538
  • Distribution of pelagic sedimentDominant component Composition Atlantic Pacific IndianTotal % Foraminiferal ooze and nannofossil oozeCalcium carbonate65 365447Pteropod ooze Calcium carbonate20.1- 0.5Diatom oozeSilica (opal)71020 12Radiolarian oozeSilica (opal)-50.53Red (actually brown) clay K, FeAl silicate26492538
  • Sediments in the ocean powerpoint

    1. 1. Sediments in the Oceans
    2. 2. sediment - matter that has been deposited by some natural process
    3. 3. smaller – easier for currents to move larger – harder for currents to move Sediment Sizes large small
    4. 4. marine sediments classified as: <ul><li>oceanic (pelagic) – </li></ul><ul><li>found in open ocean </li></ul><ul><li>further away from </li></ul><ul><li>land </li></ul><ul><li>neritic – </li></ul><ul><li>found in waters </li></ul><ul><li>above continental margins </li></ul><ul><li>closer to land - coastal </li></ul>
    5. 5. sediment types <ul><li>*terrigenous - derived from land </li></ul><ul><li>*biogenous - derived from plants and animals </li></ul><ul><li>hydrogenous (authigenic) – form from chemical reactions in the ocean </li></ul><ul><li>cosmogenous - from outer space </li></ul><ul><li>*most common </li></ul>
    6. 6. <ul><li>derived from land </li></ul><ul><li>rock fragments </li></ul><ul><li>volcanic ash </li></ul><ul><li>blown dust </li></ul><ul><li>broken down by weathering (erosion) </li></ul>Terrigenous Sediment
    7. 7. <ul><li>sources: </li></ul><ul><ul><ul><li>rivers - biggest contributors </li></ul></ul></ul><ul><ul><ul><li>glaciers </li></ul></ul></ul><ul><ul><ul><li>wind blown dust </li></ul></ul></ul><ul><ul><ul><li>coastal erosion </li></ul></ul></ul><ul><ul><ul><li>volcanic debris </li></ul></ul></ul><ul><ul><ul><li>groundwater </li></ul></ul></ul>Terrigenous Sediment
    8. 8. <ul><li>turbidite – like an underwater landslide – carries terrigenous sediment down cont. slope </li></ul>Terrigenous Sediment
    9. 9. Terrigenous Sediment dust from the Sahara Desert
    10. 10. Biogenous Sediment <ul><li>derived from plants and animals </li></ul><ul><li>mostly shells, some bones </li></ul>
    11. 11. Biogenous Sediment <ul><li>ooze – very fine sediments at least 30% biogenous in origin </li></ul><ul><ul><li>found in deep sea off continental margins </li></ul></ul><ul><ul><li>build up very slowly </li></ul></ul><ul><ul><li>two main types: </li></ul></ul><ul><li>calcareous ooze and siliceous ooze </li></ul>
    12. 12. Biogenous Sediment <ul><li>Calcareous Ooze </li></ul><ul><li>made of calcium carbonate (CaCO 3 ) - chalky </li></ul><ul><li>dissolves in very deep waters </li></ul><ul><li>includes: foraminifera (like ameba w/ shell) </li></ul><ul><li>coccolithophores (algae w/ shell) </li></ul><ul><li>pteropods (small drifting snails) </li></ul>foraminifera coccolithophores pteropods
    13. 13. Coccolithophores and a coccolithiphore bloom near England
    14. 14. Biogenous Sediment The White Cliffs of Dover made of calcareous ooze – basically chalk
    15. 15. Biogenous Sediment <ul><li>Siliceous Ooze </li></ul><ul><li>made of silicon (glass) </li></ul><ul><li>deeper than calcareous oozes and polar regions </li></ul><ul><li>includes: diatoms (algae) </li></ul><ul><ul><ul><li>radiolaria (like ameba w/ shell) </li></ul></ul></ul>diatoms radiolaria
    16. 16. Hydrogenous Sediment <ul><li>also called authigenic sediments </li></ul><ul><li>form from chemical reactions in the ocean </li></ul><ul><li>very small percentage of ocean sediments </li></ul>
    17. 17. Hydrogenous Sediment <ul><li>Manganese Nodules: </li></ul><ul><li>golf ball size chunks of manganese and iron </li></ul><ul><li>found in deep sea </li></ul><ul><li>thought would be economically valuable one day </li></ul>
    18. 18. Hydrogenous Sediment <ul><li>Phosphorites: </li></ul><ul><li>like manganese nodules, but mostly phosphorus </li></ul><ul><li>may be important some day for fertilizer </li></ul>
    19. 19. Hydrogenous Sediment <ul><li>Hydrothermal Vents: </li></ul><ul><li>like underwater hot springs at mid-ocean ridges </li></ul><ul><li>form metal sulfides </li></ul>
    20. 20. Hydrogenous Sediment <ul><li>Evaporites: </li></ul><ul><li>salts that precipitate (form solid) as water evaporates from an isolated arm of the ocean </li></ul>
    21. 21. Cosmogenous Sediment <ul><li>from outer space </li></ul><ul><li>found in trace amounts – least common </li></ul><ul><li>examples: </li></ul><ul><ul><ul><li>dust from outer space </li></ul></ul></ul><ul><ul><ul><li>meteorite debris </li></ul></ul></ul><ul><ul><ul><li>microtektites – crustal material that exits earth’s atmosphere during meteor impact and then falls back to earth – melts forming glassy teardrops </li></ul></ul></ul>
    22. 22. Where types of sediment are found:
    23. 23. sediments can be: well sorted – all one size poorly sorted – many sizes together affects: amount of water between sediment grains oxygen level types of organisms that can live there

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