Bacillariales is an order of diatoms. There are 398 species of Bacillariales, in 20 genera and 1 family. It includes groups like Bacillariaceae. Dead Bacillariales formsiliceous oozes.
Definition: Siliceous ooze is a marine sediment composed of the debris of plankton with silica shells, such as diatoms and radiolaria. This ooze is limited to areas with high biological productivity, such as the polar oceans, and upwelling zones near the equator. The least common type of sediment, it covers only 15% of the ocean floor. It accumulates at a slower rate than calcareous ooze: 0.2-1 cm / 1000 yr.
