Experiments show that between 6 and 21 GPa CaCO3 melts within 50 K of 2000 K.
Experiments place the calcite V-aragonite-liquid invariant point at 13 GPa and 1970 K.
Experiments show that Na2CO3 melting point rises with pressure to 1950 K at 17 GPa.
Experiments and simulations suggest a density crossover between calcite V and liquid.
Simulations confirm that aragonite is denser than liquid at pressures up to 30 GPa.