The type of sediment that is made up mainly of the shells of diatoms and radiolarians are called the siliceous ooze. Siliceous ooze is a siliceous pelagic sediment that covers large areas of the deep ocean floor. Calcareous ooze, siliceous ooze is formed from the tests of microorganisms; in the case of siliceous ooze, the organisms come in two varieties, diatoms and radiolarians.
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