Diatomaceous earth is derived from which prehistoric source?

• A. Silica deposits
• B. Microscopic aquatic plant remains
• C. Mineral sediments
• D. Organic matter

Answer: (B)

Diatomaceous earth is derived from the remains of microscopic aquatic plants known as diatoms. These organisms are a type of algae that have rigid silica shells. When diatoms die, their silica shells accumulate on the bottom of water bodies, forming deposits over time. These deposits are what we refer to as diatomaceous earth, which is used in various applications, including water filtration, as a filter aid, and in some cases, as an insecticide due to its abrasive properties.

While silica deposits, mineral sediments, and organic matter might have their own significance in geology and natural processes, they do not specifically define the source of diatomaceous earth. The unique characteristics and uses of diatomaceous earth stem directly from the accumulation of these microscopic aquatic plant remains.