Ocean Sediments
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Transcript of Ocean Sediments
Figure 5-1
Paleoceanography
Lithostratigraphy
Biostratigraphy
Chronostratigraphy
Magnetostratigraphy
Stable-isotopic stratigraphy
Challenger Expedition (1872-1876)◦ Baille rod
German Meteor Expedition (1925-1927)◦ Wolfgang Schott◦ Foraminifera◦ Established first links between the abundance of
marine organisms and climate
Cesare Emiliani (1922-1995)◦ Isotopes of oxygen◦ First to demonstrate that ocean conditions were
not constant through geologic time
CLIMAP project (1971-1982)
Milankovitch Cycle◦ Eccentricity◦ Obliquity◦ Precession
Integrated Ocean Drilling Program
Granular◦ Fragmentation of organic or inorganic parent
materials Biogenous Lithogenous
Chemical◦ Forming directly from dissolved compounds in
seawater Hydrogenous Authigenic
Shells & skeletons CaCO3 [calcareous] SiO3 [siliceous]
Oozes
Coccolithophorids Pteropods Foraminfera Diatoms Radiolarians
Terrigenous sediments◦ Fine to coarse◦ Most common◦ Weathering of rocks◦ Transport by rivers,
winds, volcanoes and glaciers
Derived from chemical reactions in the water
Hydrothermal Vent
Carbonates◦ Limestone-type deposits◦ Shallow, warm water
◦ Ooliths
Phosphorites◦ Phosphorus in the form of phosphate◦ Continental shelf & slope
Salts◦ High rate of evaporation in shallow areas◦ Carbonate salts, sulfate salts, then chlorides
Manganese nodules◦ Manganese, iron, nickel, cobalt & copper
Sediments derived from space
Size & shape◦ Influences sinking rate and travel time
Particle aggregation◦ Electrical attraction◦ Fecal pellets
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