Calcite Dissolution: An in situ Study in the Panama Basin

Area of Science:

• Marine Geology
• Geochemistry
• Oceanography

Background:

• Calcite dissolution is a key process in marine carbon cycling.
• The sedimentary lysocline marks a rapid decrease in calcium carbonate content in sediments.
• Understanding dissolution dynamics is crucial for interpreting paleoceanographic records.

Purpose of the Study:

• To investigate the in situ dissolution rates of calcite in the Panama Basin.
• To determine the relationship between water column dissolution and the sedimentary lysocline.
• To explore potential causes for the observed dissolution patterns.

Main Methods:

• In situ study of calcite dissolution.
• Analysis of water column and sediment properties at varying depths.
• Measurement of calcium carbonate content in sediments.

Main Results:

• Dissolution rates in the water column increase significantly below approximately 2800 meters.
• This depth coincides with the onset of the sedimentary lysocline.
• Increased dissolution appears independent of the transition from carbonate supersaturation to undersaturation.

Conclusions:

• The study indicates a potential kinetic control on the lysocline in the Panama Basin.
• The observed dissolution patterns suggest factors beyond simple saturation state influence calcite's fate.
• Further research into kinetic processes is warranted to fully understand lysocline formation.