Calcite-Aragonite Equilibrium

Abstract

Calcite-aragonite equilibrium, determined with an oscillating Griggs-Kennedy squeezer over the range 100 degrees to 575 degrees C, is given by P = 5500 (+/- 500) + 12.6 (+/- 1.5) T where pressure is in bars and temperature is in degrees Celsius. Our new determination agrees with earlier high-temperature work but is significantly different from previous low-temperature work. The equilibrium curve obtained can be used to interpret formation of aragonite during metamorphism.