Cooling rate based on schreibersite growth for the Emery mesosiderite

Computer simulation of diffusion-controlled growth of the large Ni-rich grains of schreibersite found in the Emery mesosiderite indicates that exsolution from kamacite occurred during cooling at the rate of 0.1 C/Myr. This finding agrees with the mesosiderite cooling rate determined by Powell (1969) from taenite-kamacite data. The cooling rate is the lowest found for any meteorite group, and implications for the cooling history, with a possibility of reheating, are considered. The procedure for computing a family of cooling rate curves is based on Randich's (1975) method.