Carbonate dissolution rates at the deep ocean floor. Issue 4 (27th February 2013)

• Record Type: Journal Article
• Authors: Boudreau, Bernard P.
• Is Part Of: Geophysical research letters. Volume 40:Issue 4(2013:Feb.)
• Page Start: 744
• Page End: 748
• Publication Date: 2013-02-27
• Subjects: calcite -- dissolution -- kinetics -- mass transfer; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2012GL054231
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract : [1] This paper reexamines experimental data on the seawater dissolution of CaCO3 ‐bearing sediment beds to establish that the dependence of the calcite dissolution rate is linearly dependent on the calcite saturation state of the overlying water. This linearity is inherent to the original data and is not the result of an error in the solubility product for calcite. A comparison between these linear kinetics and the rate of solute transport across the benthic boundary layer further reveals that the overall rate of dissolution at ocean depths below the saturation horizon is controlled by boundary layer transfer. A carbonate mass‐balance model for the sediment‐water interface, which includes both kinetics and boundary layer effects, predictively reproduces the currently observed CaCO3 depth distribution for two test areas in the oceans. These findings allow important simplifications in modeling CO2 neutralization in the oceans. Key Points: Seafloor CaCO3 dissolution is linear Seafloor CaCO3 dissolution is mass‐transfer controlled Diagenetic model unneeded for CaCO3 dissolution