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