Figure 3. Weight percentages of CO₂ and H₂O for selected marine sediment bulk rock compositions (see Fig. 1).

a, Gloss; b, Antilles; c Marianas; d, Vanuatu. Heavy curved lines are limiting geotherms (see Fig. 1). Values of the initial wt% CO₂ and H₂O are given in the insets (from ref. 8). The CO₂ and H₂O contents of the fluid phase can be determined by subtracting the data in these diagrams from the initial volatile contents of the protoliths.