Pd. Bons et B. Den Brok, Crystallographic preferred orientation development by dissolution-precipitation creep, J STRUC GEO, 22(11-12), 2000, pp. 1713-1722
Crystallographic preferred orientations (CPOs) in deformed rocks are common
ly interpreted as resulting from crystal plastic deformation mechanisms, wh
ere deformation is achieved by the movement of dislocations. In this paper
we investigate the possibility of CPO-development by dissolution-precipitat
ion creep or pressure solution. A numerical model is presented, which simul
ates the development of a grain aggregate that deforms by reaction-controll
ed dissolution-precipitation creep. Grains are simulated as rectangular bar
es that change their shape by growth, or dissolution of their surfaces, dep
ending on the normal stresses acting on the individual surfaces. Grains can
also rotate due to an applied vorticity (for non-coaxial deformation) and
if they have a non-equidimensional shape. For each strain increment, stress
that is applied to the grains is the same for all grains, while individual
grains deform and rotate by different amounts. A variety of CPOs develop a
t moderate strains, depending on the reaction rates of the different crysta
l-surfaces and type of deformation (uni-axial shortening, plane strain pure
shear and simple shear). The modelling results confirm that dissolution-pr
ecipitation creep may play a role in CPO-development in rocks. (C) 2000 Els
evier Science Ltd. All rights reserved.