Equilibrium and nonequilibrium oxygen isotope effects in synthetic carbonates

A suite of divalent metal (Ca, Cd, Ba) carbonates was synthesized over the temperature range 10–40°C by the classical method of slowly bubbling N2 through a bicarbonate solution. It was discovered that carbonates could be precipitated reproducibly in or out of isotopic equilibrium with the environmental solution by varying the concentrations of bicarbonate and cation. Precipitation rate had little or no influence on the isotopic composition of …