Lysocline

[1] CaCO3 content in sediment varies with different depths of the ocean, spanned by levels of separation known as the transition zone.

[1] This area is then spanned hundreds of meters by the transition zone, ending in the abyssal depths with 0% concentration.

The lysocline is the upper bound of the transition zone, where amounts of CaCO3 content begins to noticeably drop from the mid-depth 85–95% sediment.

[3] However, this creates undersaturated seawater below the saturation depth, preventing CaCO3 burial on the sea floor as the shells start to dissolve.

As the atmospheric concentration of carbon dioxide continues to increase, the CCD can be expected to decrease in depth, as the ocean's acidity rises.

The graphic presents the present-day annual mean surface omega calcite: the normalised saturation state of calcite. Areas with a value less an 1 indicate a likeliness for dissolution (undersaturated) while a value over 1 indicates areas less likely for dissolution (oversaturation).