Solubility of foraminifera in seawater at high pressures

Abstract

In situ pH electrodes were used to show that solution of pelagic calcareous foraminifera occurs in seawater at pressures between 100 and 1, 000 atm. The results confirm earlier work which had indicated that the carbonate compensation depth is not a boundary between super and undersaturated waters. The degree of solution and hence diagenetic alterations which may affect the geologic record were found to depend on the calcareous species. The results of this work also yielded physicochemical knowledge on the effect of pressure on carbonate ion pairs, on the relative solubilities of calcite and aragonite, and on rates of solution. There is no solubility in the thermodynamic sense but this fact was shown not to affect the value of solubility measurements for oceanographic and geochemical work.