P increases up
P increases down

Figure 2.06. Effect of pressure on melting. The melting temperature of pure Mg-diopside is shown as a function of pressure. Notice that the melting temperature rises as pressure increases. Use the buttons too see similar behavior of halite melting and peridotite melting. Isothermal decompression can lead to melting for these and most solids. The diagrams drafted for this figure are based on laboratory melting experimental at pressure reported in or summarized by Rigden et al. (1989) for diopside, by Akella et al. (1969) for halite, and by Mckenzie and Bickle (1988) for peridotite.