Oceanography chpt. 4

exam 1

Why are most deep-ocean lithogenous deposits composed of fine-grained sediments?

there is not enough energy to move larger grain sizes to the deep ocean.

a sediment deposit consisting of mostly large grain sizes (i.e., cobbles, pebbles) indicates that what energy regime exists in the area?

high-energy

what area of the ocean floor usually has the thickest sediment deposits?

continental shelf

what is the sediment type that comes from dissolved material precipitating out of the water?

hydrogenous

what is the most significant mode of transport of lithogenous sediment?

water

what is required in order for a manganese nodule to form?

a nucleation object

a calcareous ooze would be dominated by which of the following organisms?

foraminiferan

a siliceous ooze is dominated by which microscopic algae?

diatom

for a sediment to be considered a biogenic ooze, what minimum percentage must be biological material?

30 percent

a core section with a high amount of silica would most likely indicate what about the time it was deposited?

that there was a high amount of surface productivity.

sediment deposits found on continental shelves are also referred to as

nectric deposits

a poorly sorted lithogenous sediment deposit was most likely transported by what?

glaciers

how can calcareous ooze be found at depths lower than 5,000 meters (3.1 miles)?

it is buried under other sediment types

what is the type of sediment that is not from Earth?

cosmogenous

what is the sediment type that comes from the remains of previously living organisms?

biogenous

what is the type of sediment that is derived from the continents?

lithogenous