OC Unit: Ocean Sediments

turbidite

A terrigenous sediment deposited by a turbidity current; typically, coarse-grained layers of nearshore origin interleaved with finer sediments.

terrigenous sediment

Sediment derived from the land and transported to the ocean by wind and flowing water.

hydrogenous sediment

Sediment formed when solid material in seawater falls, as a precipitate, out to the ocean floor or is left behind after water evaporates.

calcareous ooze

Sediment of at least 30% biological origin, composed mostly of the hard remains of organisms containing calcium carbonate.

siliceous ooze

Sediment of at least 30% biological origin, composed mostly of the hard remains of silica-containing organisms.

biogenous sediment

Sediment of biological origin.

volcanogenous sediment

Sediments with volcanic origin.

ferromanganese nodules

Solid mass of hydrogenous sediment containing iron and manganese.

calcium carbonate compensation depth (CCD)

The depth at which the rate of build-up of calcareous sediments equals the rate those sediments are dissolved. Below this depth, sediment contains little or no calcium carbonate.

turbidity current

Underwater avalanches of thick, muddy sediments accumulated on the continental shelf that speed down the continental slope into deep water.