Experimentally produced preferred orientation in synthetic mica aggregates

An experimental study of the behaviour of micaceous aggregates undergoing deformation during and after mica growth has been undertaken using pelletised powder consisting of an oxide mix with the stoichiometry of phlogopite. The influences of temperature, pore fluid content, strain, strainrate, and pre-mixing time have been examined. It is concluded that oriented growth of anisotropic crystals, due either to anisotropy of pore structure and hence permeability or to pressure solution phenomena, gives rise to most of the preferred orientation observed.