Chapter 11 Flashcards
(35 cards)
What is lithogenous sediment? Where did it originate?
- Sediment from rocks
* Result of weathering and erosion
What is the principal component of most beach sand? Lithogenous
didn’t originate there
How is the lithogenous sediment transported?
Wind and currents
What is calving
Calving-when a piece of the glacier breaks off, forms icebergs
How is lithogenous sediment classified? Include size and sorting.
Grain Size
–Mud –very small (think of flour or powdered sugar)
–Sand-less than 2 mm in size (think of granulated sugar or a sand box)
–Gravel-anything bigger than 2 mm
Streams and lithogenous
- Streams and run-off from continents
* Highest concentrations of lithogenous sediment near the coasts!
Wind and lithogenous
Blows dust and clay sized particles into the ocean
Glaciers and lithogenous
Calving-when a piece of the glacier breaks off, forms icebergs
What is biogenous sediment?
From living organisms or their remains
What is biogenous sediment made of
–Includes shells, bones, coral, skeletal parts
–Includes excretions and secretions
–Fecal Pellets-undigested food, sinks to deep ocean-major food source in the deeper parts of the ocean
What is the chemical make up of a diatom?
Silica
What is a radiolarians made of?
Silica
What is a coccolithophores made of
Calcium carbonate
What is a foraminifera made of?
Calcium carbonate
What is hydrogenous sediment? How are they formed?
Precipitated from seawater. Form as coatings on other particles
Describe manganese nodules
- Black nodules
- Contain Manganese, Iron, copper, cobalt, and nickel
- Form as coatings on other particles
Where are deposits of manganese nodules found?
Manganese (or polymetallic) nodules occur widely on the sediment-covered abyssal plains at depths of 3500 to 6500 m. Origin of Manganese Nodules: Manganese nodules form on the ocean floor by the slow precipitation of metallic minerals extracted directly from seawater or pore waters of the sea-bottom sediments.
What is an oolith? How big are they? How are they formed?
•Tiny spheres of calcite•Precipitate out of seawater
What is cosmogenous sediment?
–Meteorites–Space Dust–Tektites
What is a tektite?
- Form from a rock that was hit by a meteorite, then melted, then cooled back into the rock
- A tektite is not the meteorite, but the rock the meteorite crashed into
What is a neritic? What type of sediment dominates?
relating to or denoting the shallow part of the sea near a coast and overlying the continental shelf.
are dominated by lithogenous sources and are typically deposited quickly.
What is a delta?
Fan shaped deposit formed when a stream enters the ocean and drops all of its sediment
What is a wetland?
•Low-lying, flat areas•Covered with water at least part of year
Define pelagic.
(chiefly of fish) inhabiting the upper layers of the open sea.