The oceanic balance between the influx of alkalinity from rivers and the loss by burial of calcite in seafloor sediments can determine the partial pressure of carbon dioxide of the surface ocean, and thus of the atmosphere, on glacial-interglacial time scales. The magnitude of the effect is very sensitive to the factors that drive the dissolution of calcium carbonate and the mechanisms of dissolution on the sea floor. In this study the principal investigator would collaborate with several other marine carbonate experts in an attempt to help resolve a major question in this field: the kinetics and relative importance of calcite dissolution by respiratory processes and by simple dissolution/precipitation. By following oxygen, pH, and carbonate measurements in in-situ benthic chambers and through back-up laboratory studies of calcite precipitation/dissolution kinetics, the principal investigator anticipates that he will be able to address this problem by eliminating uncertainties inherent in similar studies conducted to date.
