Subcritical dyke propagation in a host rock with temperature-dependent viscoelastic properties

Abstract

SUMMARY In this paper, we examine the effects of temperature-dependent viscoelastic properties of the host rock on the subcritical growth of a dyke from a magma chamber. A theoretical relationship between the velocity of subcritical dyke growth and dyke length is established using a perturbation solution of stress intensity factor at the dyke tip and a viscoelastic crack growth theory in which the temperature-dependent creep properties are taken into account. The temperature field around the dyke is calculated using an analytic solution. The numerical results for a dyke subcritically propagating from a magma chamber indicate that while the general dyke growth characteristics are similar to those with constant creep properties, the subcritical dyke growth velocity is increased by an order of magnitude by considering the temperature dependence of the creep properties. Hence, the subcritical growth duration before the dyke reaches the unstable growth state is significantly shortened.