Lysocline

Definition

The lysocline is the depth in the ocean at which the rate of dissolution of calcium carbonate exceeds the rate of supply, leading to a rapid decrease in the concentration of calcium carbonate in the sediments. This depth is crucial for understanding how marine sediments are distributed and formed, as it marks the transition between areas where calcium carbonate can accumulate and those where it dissolves before reaching the seafloor.

5 Must Know Facts For Your Next Test

1. The lysocline varies geographically and is influenced by factors such as temperature, pressure, and water chemistry, particularly the concentration of dissolved carbon dioxide.
2. In warmer waters, the lysocline is typically shallower due to increased dissolution rates of calcium carbonate compared to colder regions.
3. Above the lysocline, calcium carbonate can accumulate, forming sediments like chalk and limestone, which can be important geological resources.
4. Understanding the location of the lysocline helps scientists predict changes in sediment distribution and potential impacts on marine ecosystems due to climate change.
5. The concept of the lysocline is essential for interpreting sediment cores, as it indicates historical changes in ocean chemistry and climate over geological time.

Review Questions

• How does the lysocline influence sediment types and their distribution in marine environments?
  • The lysocline marks a significant depth where calcium carbonate begins to dissolve more rapidly than it accumulates. This influences sediment types by determining where biogenic sediments composed of calcium carbonate can form and persist. Above this layer, sediments rich in calcium carbonate can accumulate, while below it, sediments tend to be more siliceous or consist of other materials. This distribution pattern is crucial for understanding the composition and type of marine sediments found at different depths.
• Discuss the relationship between lysocline depth and factors like temperature and pressure in marine systems.
  • The depth of the lysocline is closely linked to temperature and pressure conditions in ocean waters. In general, warmer waters promote higher dissolution rates of calcium carbonate, resulting in a shallower lysocline. Conversely, as pressure increases with depth, dissolution rates also change. Consequently, these environmental factors create variations in lysocline depth across different regions of the ocean, impacting where sediment types are found and how they accumulate over time.
• Evaluate the implications of changing oceanic conditions on the lysocline and its effects on marine sedimentation patterns.
  • As oceanic conditions change due to factors like global warming and increased carbon dioxide levels, shifts in the lysocline could have significant consequences for marine sedimentation patterns. A deeper lysocline could lead to more extensive areas where calcium carbonate dissolves before reaching the seafloor, altering sediment composition and potentially impacting marine ecosystems that depend on those sediments. This change could affect organisms that rely on biogenic sediments for habitat or food, ultimately influencing broader ecological dynamics within marine environments.

Related terms

Calcium Carbonate Compensation Depth (CCD): The CCD is the depth in the ocean where the rate of dissolution of calcium carbonate equals the rate of accumulation, typically located below the lysocline.

Biogenic Sediments: Sediments that are primarily composed of the remains of marine organisms, such as foraminifera and coccolithophores, which produce calcium carbonate.

Pelagic Sediments: Sediments that accumulate on the ocean floor, primarily from materials settling through the water column, including biogenic, terrigenous, and authigenic sources.