Correspondence: Reply to 'Numerical modelling of the PERM anomaly and the Emeishan large igneous province'

Tectonic plates and plate boundaries migrate substantially through time and mantle plumes are generally accepted to be mobile within the convecting mantle, but it has been proposed that large low shear velocity provinces (LLSVPs) could have been fixed and rigid for as much as 540 million years (Myr) The hypotheses of fixed and rigid LLSVPs cannot be easily tested in the absence of constraints on the past location of lowermost mantle structures. We evaluated the hypothesis of lower mantle thermochemical structure fixity with numerical experiments. As in earlier studies, we argue11 that the location of lower mantle thermochemical structures has changed through time.