PARTITIONING OF NONCOAXIALITY IN DEFORMING LAYERED ROCK MASSES

Partitioning of non-coaxiality and other flow parameters in deforming layered rock masses with nearly incompressible Newtonian rheology is examined in two dimensions by the finite element method. The results show that layers with viscosity contrast in suitable orientation deform by different and even by a reverse sense of non-coaxiality. This remarkable partitioning of non-coaxiality is due to a large rotation rate of instantaneous stretching axes in a heterogeneous body as a result of geometry changing through deformation rather than through rotation of material lines.