OCE 4008 Ch.5
At what location are diatom oozes most common.
High latitudes and in areas of upwelling
The White Cliffs of Dover in England were formed as a result of which marine organism?
Coccolithophore
Deep-ocean sediments found under the central part of ocean gyres are typically composed of:
Fine clays
Why is the average sediment thickness in the Pacific Ocean less than that of the Atlantic Ocean?
Ocean trenches trap sediments
The ____ comprise the highest percent of ocean area, but contain the lowest percent of sediment volume.
deep ocean floor
What type of deep ocean sediment is most common in the deep-ocean basins surrounding the Antarctic?
diatom ooze
A poorly-sorted sediment would most likely be found in a(n) _____.
eroding shore cliff
Which is an example of an evaporite?
gypsum; calcium carbonate
Which areas of the ocean is most likely to have the least accumulation of sediment?
oceanic ridge
What is an example of authigenic sediment?
Phosphorite deposits
An example of an organism with a silicon-based shell is ______________.
Radiolaria
Typically smaller particles
Are more easily transported by streams, waves, and currents
What occurs below the calcium carbonate compensation depth?
Calcium carbonate begins to dissolve
The science of paleoceanography analyzes variations in the relative abundance of stable isotopes of oxygen preserved within the carbonate shells found in deep sea sediment, which allows them to interpret
Changes in the temperature of surface and deep water over time
The discipline that is tasked with the analysis of layered sedimentary deposits whether in the ocean or on land.
Stratigraphy
What would you expect to happen to sediment during a glaciation?
The continental shelves would be exposed because of lower sea levels and the sediment would be carried by rivers to the shelf edge
What inference can be made from the biogenic marine limestone near the top of Mount Everest, the world's highest peak?
The lithified sediments are thrust up pieces of the ancient seafloor
Why would you expect that seafloor samples taken farther from land usually contain a greater proportion of biogenous sediments than those obtained near the continental margins?
There is less terrigenous material far from shore.
What relationship can be established between sorting and the energy of the environment?
Well sorted sediments are found at the base of a rapidly eroding shore cliff
The west coast of South America is known for its seasonal upwelling. What kind of sediment is likely to be abundant in this area?
biogenous
What is the particle size distribution from largest to smallest?
boulder → granule → coarse sand → coarse silt
An abundance of foraminifera shells would be described as what type of sediment?
calcareous ooze
Which particle size is transported the farthest by waves and currents?
clay
Which particle size has the fastest settling velocity in still water?
coarse sand
Most marine sediments are composed of what size of particles?
sand, silt, clay
Which geological processes explains why the ocean floors are so young?
subduction
What is the most abundant marine sediment in total volume?
terrigenous
What is the primary origin of most neritic sediments?
terrigenous
What type of marine sediment is derived from igneous rock?
terrigenous
Which deposits are the result of gravity-propelled currents that produce graded layers of sediment deposits?
turbidites