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

2200x