Thermal structure of continental subduction zone: high temperature caused by the removal of the preceding oceanic slab

Abstract

The thermal structure of the continental subduction zone can be deduced from high-pressure and ultra-high-pressure rock samples or numerical simulation. However, petrological data indicate that the temperature of subducted continental plates is generally higher than that derived from numerical simulation. In this paper, a two-dimensional kinematic model is used to study the thermal structure of continental subduction zones, with or without a preceding oceanic slab. The results show that the removal of the preceding oceanic slab can effectively increase the slab surface temperature of the continental subduction zone in the early stage of subduction. This can sufficiently explain the difference between the cold thermal structure obtained from previous modeling results and the hot thermal structure obtained from rock sample data.