Which sediment is defined as sediment of biological origin formed from calcareous or siliceous debris?

• A. Authigenic Sediment
• B. Clay
• C. Biogenous Sediment
• D. Calcareous ooze

Answer: (C)

Biogenous sediment is formed from the tests and shells of microscopic organisms, which are either calcareous (calcium carbonate) or siliceous (silica). When these biological remains settle to the seafloor and accumulate, they create a sediment that originates from living matter. The key idea is that the material comes from organisms and is made of calcium carbonate or silica. Calcareous ooze is a specific type of biogenous sediment dominated by calcium carbonate, but the general category includes both calcareous and siliceous debris. This distinguishes it from authigenic sediment, which forms by chemical precipitation in place, and from lithogenous clays, which come from weathered rocks.