Assume an exoplanet like a colder (roughly habitable temperatures throughout) Venus with liquid water and a layer of supercritical carbon dioxide at the bottom of it's ocean basins. What would happen to that water? Would the water:
- A: Form a separate ocean on top of the supercritical CO2 with minimal mixing because of CO2's higher molecular weight? (44.009 g·mol^−1 vs 18.015 g·mol^−1)
- B: Form a separate ocean below the supercritical CO2 because of it's higher density? (79.08 to 996.16 kg/m3 vs 1000 to 1050 kg/m3)
- C: Dissolve into the supercritical CO2 to form a solution? How much water could the CO2 dissolve by volume?
- D: Would the situation never occur in the first place, since the water ocean would have to form before the supercritical CO2, and after that the gaseous CO2 would never be able to reach the ocean depths in enough quantity to form a supercritical CO2 layer?
This answer Seems to imply that it would be B, but I'm not sure if that accounts for the water dissolving and the CO2's supercriticality.