There are two basic types of ocean floor sediment. Terrigenous sediment washes off land into the ocean. Pelagic sediment is created within the ocean.
Terrigenous sediment finds its way into the ocean through rivers and streams, run-off from rainfall, winds, and glaciers. Quartz, feldspar, and clay mineral deposits common to terrestrial rock get into the ocean this way.
Pelagic sediment comes from many sources in the ocean. Decaying life forms supply sedimentary particles, especially creatures with shells of calcium carbonate, which is a compound found in chalk and limestone.
Many microscopic creatures, such as phytoplankton, grow these shells. After death, the animals sink toward the ocean floor. These decaying animals with their calcium carbonate shells on the floor are called calcareous oozes. If the ocean floor is more than 16,500 feet (5,030 meters) deep, however, pressure disintegrates the shells and they dissolve into the water.
Some microscopic organisms grow silica shells. Siliceous oozes are the undissolved remains of these shells. Silicon is an abundant element found in quartz and flint. People use silicon in creating glass and ceramics.