What does the term 'bioturbation' refer to in the context of sedimentology?

The term 'bioturbation' specifically refers to the mixing of sediments by living organisms. This process is crucial in sedimentology, as it significantly influences the structure and composition of sediment layers. Organisms such as burrowing organisms, worms, and other benthic organisms disturb the sediment as they move through it, which alters the physical and chemical characteristics of the sediment. This mixing can affect nutrient availability, oxygen levels, and the overall ecosystem dynamics within the sediment layers.

Bioturbation plays a vital role in the cycling of materials within marine sediments and can impact geochemical processes as well. By rearranging sediment particles and creating channels or pores, these organisms facilitate the movement of water and nutrients, thereby enhancing the biological productivity of the sediment environment. This process is distinct from physical layering, sediment erosion, or chemical alteration, which describe different aspects of sediment dynamics.