Contribution of deviatoric stresses to metamorphic P‐T paths: an example appropriate to low‐P, high‐T metamorphism

Abstract

P‐T paths for a simple situation appropriate to many low‐P, high‐T (LPHT) terranes in which metamorphism and deformation are localized by advection of heat in magmas, has been modelled assuming a medium with a power‐law rheology with an inverse exponential dependence of stress and temperature and capable of sustaining deviatoric stress, τ, in the order of 100 MPa at 400d̀ C and strain rates of up to 10‐13s‐1. Numerical simulations and analytical approximations for P‐T histories appropriate for simple convergent deformation histories show that the destruction of the deviatoric stress field around large intrusions may result in significant decompression near the metamorphic temperature peak. M..