Some subducted material appears to reach the lower mantle, while in other regions, this material is impeded from sinking further, possibly due to a phase transition from spinel to silicate perovskite and magnesiowustite, an endothermic reaction.
In certain locations, subducted material appears to descend into the lower mantle. However, in other areas, this material encounters resistance, potentially caused by a phase change from spinel to silicate perovskite and magnesiowustite, which is an energy-absorbing process.