Sediment accumulation

Definition

Sediment accumulation refers to the process by which particles settle and build up on the ocean floor over time. This process is crucial in shaping the geological features of the oceanic crust, influencing its formation and evolution. As sediments accumulate, they can compact and cement together, contributing to the development of sedimentary rock layers and impacting marine ecosystems and nutrient cycling.

5 Must Know Facts For Your Next Test

1. Sediment accumulation rates can vary significantly across different oceanic regions due to factors such as water depth, current strength, and biological productivity.
2. Sediments can originate from both terrestrial sources, like rivers and erosion, and marine sources, including the remains of marine organisms.
3. The accumulation of sediments plays a key role in the formation of oceanic features such as abyssal plains, continental slopes, and ocean trenches.
4. Understanding sediment accumulation helps scientists interpret past climate conditions through the study of sediment cores, which reveal changes in sediment composition over time.
5. In areas of high sediment accumulation, such as river deltas, the resulting deposits can create rich habitats for diverse marine life and influence coastal ecosystems.

Review Questions

• How does sediment accumulation influence the geological features of the oceanic crust?
  • Sediment accumulation significantly impacts the geological features of the oceanic crust by contributing to the formation of various structures like abyssal plains and continental slopes. As sediments settle over time, they layer upon one another, compacting and often leading to lithification into sedimentary rock. This process shapes the seafloor's topography and plays a role in nutrient cycling within marine ecosystems.
• Discuss the differences between biogenic sediments and terrigenous sediments in relation to sediment accumulation.
  • Biogenic sediments are derived from organic materials produced by living organisms, such as shells and skeletal remains, while terrigenous sediments originate from land-based processes like erosion and river transport. The accumulation of these two types of sediments can differ markedly in location; biogenic sediments are typically more prevalent in areas with high biological productivity, like coral reefs or upwelling zones, whereas terrigenous sediments are often found closer to shorelines or river mouths. Understanding these differences is essential for interpreting sedimentary records and their implications for past environments.
• Evaluate the impact of turbidity currents on sediment accumulation patterns in deep-sea environments.
  • Turbidity currents have a significant impact on sediment accumulation patterns in deep-sea environments by rapidly transporting large volumes of sediment down continental slopes into deeper ocean basins. These underwater flows can lead to a quick deposition of sediments over wide areas, creating features such as submarine fans. The mixing and distribution caused by turbidity currents contribute to the overall complexity of sediment layers found in deep-sea deposits, which is vital for reconstructing geological history and understanding past oceanic conditions.

Related terms

Lithification: The process through which sediments compact under pressure and cement together to form solid rock.

Biogenic sediments: Sediments that are composed of organic materials, such as shells and skeletons from marine organisms.

Turbidity currents: Underwater flows of sediment-laden water that can transport large amounts of sediment down continental slopes into deeper ocean basins.