Effect of a pure C atmosphere: The partial pressures of selected vaporised species (O₂, SiO, TiO, Fe, Na, and K) in a pure C volatile atmosphere above a BSE lava ocean are shown using solid lines, while the dashed lines are used to indicate their partial pressures in volatile free atmospheres. In the bottom row (i and j) we also show the partial pressures of the dominant C species CO and CO₂. The left panels (a, c, e, g, and i) show the partial pressures as a function of total volatile pressure at a fixed surface temperature of 3000 K. The right panels (b, d, f, h, and j) show the partial pressures as a function of surface temperature at a fixed total volatile pressure of 1 bar.