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Marine Sediment
Classified by: location, source, chemical composition, origin
Marine Sediment: why important?
Exs: Terrigenous, Lithogenous, Biogenous,
Authigenic & Hydrogenous
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• The building of the continents, marine strata
Paleo-oceanography: skeletal remains used to
interpret history of life and past current patterns,
ie. Antarctic Circumpolar Current (ACC).
• Variations of climate and seawater temperature
over time: 18O:16O
• Paleo-geography of ocean lithosphere / SFS
• Biomedical potential
• Seabed Resources: Phosphorites, Sulfur,
Sand & Gravel, Coal, Oil & Gas and Methane
Hydrates
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Shallow to Intermediate Marine, 540my
Tasmanian Sea opens ~34my
Drake Passage opens between 20 – 40 my
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Marine Sediment: why important?
• The building of the continents, marine strata
• Paleo-oceanography: skeletal remains used to
interpret history of life and past current patterns,
ie. Antarctic Circumpolar Current (ACC).
• Variations of climate and seawater temperature
over time: 18O:16O
• Paleo-geography of ocean lithosphere / SFS
• Biomedical potential
• Seabed Resources: Phosphorites, Sulfur,
Sand & Gravel, Coal, Oil & Gas and Methane
Hydrates
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Marine Sediment: why important?
http://www.sciencedirect.com/sc
ience/article/pii/S094450131200
0754
http://www.reuters.com/article/h
ealth-antibiotics-searchidUSL6N0QJ3OH20140817
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Seabed Resources
(sand and gravel)
http://www.mii.org/Minerals/photosandgr.html
• Annual world production of sand/gravel is ~1.2 billion
metric tons with a potential reserve of 800 billion metric
tons.
• United Kingdom and Japan: 20% of sand/gravel used
comes from the seafloor.
• US has reserves of ~450 billion tons of sand/gravel off
NE coast.
• Bahamas have ~100 billion metric tons of calcium
carbonate sands.
• In SW Pacific sands are mined for Fe, Pt, Sn, Au, U and
Diamonds
• Phosphorites off coasts of Florida, N. Carolina, CA,
Mexico, Peru, Japan and Australia. World reserves 11
estimated at ~50 billion tons.
• The building of the continents, marine strata
Paleo-oceanography: skeletal remains used to
interpret history of life and past current patterns,
ie. Antarctic Circumpolar Current (ACC).
Variations of climate and seawater temperature
over time: 18O:16O
• Paleo-geography of ocean lithosphere / SFS
• Biomedical potential
• Seabed Resources: Phosphorites, Sulfur,
Sand & Gravel, Coal, Oil & Gas and Methane
Hydrates
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Seabed Resources
(coal, oil and natural gas)
• Japan is currently mining undersea coal deposits
• In 2006, estimations of undiscovered offshore
resources in US: ~86 billion barrels of oil and ~420
trillion feet of gas.
• In 1998 worldwide, ~32% of oil and 24% of gas
production came from offshore wells.
• Major Offshore Oil Fields: Gulf of Mexico, Persian
Gulf, the North Sea, North Australia, Southern CA,
West Africa, Brazil and Vietnam
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Methane or Gas Hydrates
Why Study Marine Sediment?
Energy Source, Seafloor Stability, Climate Change
From text book
• Provide information about Earth and its
environmental systems on long time scales
• Can provide information about past climate
change
• Can provide information about seafloor habitats
and how they impact marine organisms
• Locating offshore mineral resources
• Map offshore pollution
• Identify sites for coastal structures and oil
platforms
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Sampling Methods
Figure 3.25a
Chain Basket, Basalts from ~8km near Tonga Tench
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Figure 3.27e
• Phleger Gravity
Corer
Piston
Corer
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Glacial
Maximum
17,000 years
B.P.
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~17 kilometers
Shelf Sediment
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Ice Rafted
Sediment
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Boulder to clay size
particles also eroded
and transported to
oceans via glacial ice
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Glacier termination in
circum-polar oceans
results in calving and
iceberg formation
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As ice (or icebergs)
melt, entrained material
is deposited on the
ocean floor
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Continental Slopes and Rises
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Deep Marine Sediment
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Cosmogenous Sediment
Micrometeorite Dust & Tektite Strewnfields
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Hydrogenous Sediments
Manganese Nodules, North Central Pacific, 5157 meters
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Kaolinite
Types of Lithogenous Deep Marine Sediment
Illite
Chlorite
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Biogenous Deep Marine Sediment
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1000 microns = 1 mm
Figure 3.21a
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https://www.youtube.com/watch?v=B4HSpmiR8Uo
@ 1:11, 1;31 and 1:48
The North Downs Formation, upper Cretaceous,
mostly coccoliths with some quartz and clay
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The North Downs Formation, upper Cretaceous,
mostly coccoliths with some quartz and clay
http://montereybayaquarium.tumblr.com/post/124365302488/why-is-the-bay-so-blue-hint-the-white-cliffs-of
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Siliceous Oozes
Diatoms & Radiolarians
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Figure 3.21b
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Biogenous Sediment
• Derived from organisms
• “Ooze” contains >30% biogenous material
• Calcareous oozes
– Algae (Phytoplankton): coccolithophorids
– Protozoa, single celled, (Zooplankton): foraminifera
– Animals, Snails: pteropods
• Siliceous oozes
– Algae (Phytoplankton): diatoms
– Protozoa, single celled, (Zooplankton): radiolaria
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ACD
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Marine Sediment Practice Quiz
Ocean bottom sediment map. Lithogenous areas are mauve,
biogenous areas are purple and brown (purple = siliceous
ooze, brown = calcareous ooze), and hydrogenous areas are
blue.
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1) Define Montmorillonite.
2) What is a Foram?
3) What is the CCD?
4) Where does Kaolinite occur in relatively high
percentages on the surface of the ocean floor?
5) What is an example of a marine organism that makes
it’s shell out of Calcitic material? Aragonitic material?
6) What is the difference between Residual and Relict
Shelf Sediments?
7) What process is common on Continental Slopes?
8) What would we never find on the surface of the
seafloor below the CCD? Below the ACD?
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