Lake sediment is a type of material that accumulates at the bottom of a lake over time. It is composed of organic and inorganic matter, such as silt, clay, and other particles. The term 'OOZE' is used to describe this type of sediment, which is usually found in shallow water and is made up of very fine particles. Oozes are important for providing nutrients to aquatic life and can also be used to study the history of a lake.