Abstract
This paper defines a synthetic slip plane as the linear combination of a pair of twinned and untwinned e-planes in a single calcite crystal. This auxiliary slip plane is dependent upon neither the twinned e-plane nor the untwinned e-plane. It can be used together with the twinned e-plane either to further constrain the extents of the compression and tension axes in graphic dynamic analysis or to better estimate the reduced stress in numerical dynamic analysis. Highlights •The linear combination of twinned and untwinned e-planes in a calcite crystal defines the synthetic slip plane.•The synthetic slip plane can be incorporated into graphic and numerical dynamic analysis.