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LITHOGENOUS SEDIMENT- Pelagic. "Red Clay" -- fine terrigenous dust + volcanic ash Settles eventually, everywhere Dominant only where other types absent. Class #12. OCEAN SEDIMENTS Cosmogenous Biogenous Hydrogenous. OCEAN SEDIMENTS Sources (origins) Distribution TYPES (BY SOURCE): - PowerPoint PPT Presentation
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"Red Clay""Red Clay" -- fine terrigenous dust + volcanic ash -- fine terrigenous dust + volcanic ash–Settles eventually, everywhereSettles eventually, everywhere–Dominant only where other types absentDominant only where other types absent
LITHOGENOUS SEDIMENT- PelagicLITHOGENOUS SEDIMENT- Pelagic
Class #12
OCEAN SEDIMENTSCosmogenousBiogenousHydrogenous
OCEAN SEDIMENTSOCEAN SEDIMENTSSources (origins)Sources (origins)DistributionDistribution
TYPES (BY SOURCE):TYPES (BY SOURCE):Lithogenous ("rock-derived')Lithogenous ("rock-derived')Biogenous ("life-derived")Biogenous ("life-derived")Hydrogenous ("water-derived")Hydrogenous ("water-derived")Cosmogenous ("cosmic-derived")Cosmogenous ("cosmic-derived")
Sediment TypesType Source Areas Examples
Lithogenous Eroded RockVolcanoesAirborne Dust
EverywhereSandsMudsRed Clay
Biogenous LivingOrganisms
Everywhere PlantsCoralsShellsOozes
Hydrogenous ChemicalPrecipitation
NeriticPelagic
Mn NodulesPhosphates
Cosmogenous Space Pelagic Micro-Meteorites
Micro-meteoritesMicro-meteorites silicates, iron metalssilicates, iron metalsvery small quantities (noticeable in red very small quantities (noticeable in red clay)clay)
COSMOGENOUS SEDIMENTSCOSMOGENOUS SEDIMENTS
Sediment TypesType Source Areas Examples
Lithogenous Eroded RockVolcanoesAirborne Dust
EverywhereSandsMudsRed Clay
Biogenous LivingOrganisms
Everywhere PlantsCoralsShellsOozes
Hydrogenous ChemicalPrecipitation
NeriticPelagic
Mn NodulesPhosphates
Cosmogenous Space Pelagic Micro-Meteorites
1)1) Large fragments: warm, shallow areasLarge fragments: warm, shallow areas– clams, coralsclams, corals– Very thick accumulations in some placesVery thick accumulations in some places
BIOGENOUS SEDIMENTS -- produced BIOGENOUS SEDIMENTS -- produced directly by living organismsdirectly by living organisms
2) Everywhere: Tiny particles produced...2) Everywhere: Tiny particles produced...– Pelagic sediment Pelagic sediment – Shells or skeletons of microplanktonShells or skeletons of microplankton– Biogenous "oozes” (>30% biogenous material)Biogenous "oozes” (>30% biogenous material)
• Calcareous ooze Calcareous ooze – CaCOCaCO33 = calcium carbonate = calcium carbonate
• Siliceous ooze Siliceous ooze – SiOSiO2 2 = silica (+ H= silica (+ H22O)O)
Calcareous ooze: Coccoliths + Foraminifers
Siliceous ooze: Diatoms and/or Radiolarians
Material Produced
Algae Protozoans
CaCO3 Coccolithophores Foraminifera
SiO2 Diatoms Radiolarians
Single –celled organisms that make Single –celled organisms that make tiny shells/skeletons that settle to the tiny shells/skeletons that settle to the ocean bottom (biogenous seds).ocean bottom (biogenous seds).
1. 1. Siliceous oozesSiliceous oozes• Controlled by nutrients: High Si, N, P, and Fe Controlled by nutrients: High Si, N, P, and Fe causes high productivity; causes high productivity; upwelling zonesupwelling zones
2. Calcareous particles- almost everywhere, but in 2. Calcareous particles- almost everywhere, but in some places they are dissolved before they get to some places they are dissolved before they get to the bottomthe bottom
Where do we find biogenous oozes?Where do we find biogenous oozes?
2. CaCO3 particles dissolve quickly below the “Carbonate Compensation Depth” (CCD)• Atlantic: ~ 4,000 m depth• Pacific: ~ 500 - 1,500 m depth
• SiO2 particles dissolved more slowly (everywhere)• Siliceous ooze can collect in deep areas• But…Must accumulate quickly- high productivity Must accumulate quickly- high productivity
areasareas
3. NOT dominant near continents, usually:Too much terrigenous sediment
Where do we find biogenous oozes?- MORE
Sediment TypesType Source Areas Examples
Lithogenous Eroded RockVolcanoesAirborne Dust
EverywhereSandsMudsRed Clay
Biogenous LivingOrganisms
Everywhere PlantsCoralsShellsOozes
Hydrogenous ChemicalPrecipitation
NeriticPelagic
Mn NodulesPhosphates
Cosmogenous Space Pelagic Micro-Meteorites
CaCOCaCO33 is very important is very important
chemicallychemically
HYDROGENEOUS SEDIMENTS:HYDROGENEOUS SEDIMENTS:precipitation of dissolved elements in waterprecipitation of dissolved elements in water
1.1. EvaporitesEvaporitesEvaporation in isolated basinsEvaporation in isolated basins
•E.g., Mediterranean Sea 6 M.Y. agoE.g., Mediterranean Sea 6 M.Y. ago• Precipitation of "salts" Precipitation of "salts"
•NaCl (halite) NaCl (halite) •CaSOCaSO44• 2H• 2H22O (gypsum)O (gypsum)
Salt Mine under Detroit: Shallow sea Salt Mine under Detroit: Shallow sea over 400 m.y. agoover 400 m.y. ago
2. Manganese nodules and crusts2. Manganese nodules and crusts• Mn + Fe oxides (+ Cu, Co, Ni) Mn + Fe oxides (+ Cu, Co, Ni) • In deep ocean basins and along mid-ocean In deep ocean basins and along mid-ocean
ridgesridges
• Origin: -- chemical reaction between Origin: -- chemical reaction between oxygen in water and dissolved Mn +Feoxygen in water and dissolved Mn +Fe
• Mn + Fe come mostly from sediments and Mn + Fe come mostly from sediments and hydrothermal ventshydrothermal vents
3) Phosphate minerals3) Phosphate minerals• P released when organic matter P released when organic matter
degrades- Minerals precipitateddegrades- Minerals precipitated• On Cont. shelvesOn Cont. shelves
4) Metal sulfides from hydrothermal vents4) Metal sulfides from hydrothermal vents• Collect on ocean floorCollect on ocean floor• Metal-rich (gold, copper)Metal-rich (gold, copper)
Fig. 4.18