Figure 2.07. Subduction Zone Temperatures. Temperature contours (100°C interval) are based on a subduction zone model by Kelemen and others (2003, figure 6B). Convection moves cold oceanic lithosphere into the hot mantle too fast for temperature equilibration at shallow depths. Temperature contours show that the subducted lithosphere is much cooler than the surrounding mantle. The dark gray band represents ocean crust and any subducted sediment. The result is that temperatures of subducted sediment increase with pressure along a gradient that is only about 10°C/km.
