The texture of cross-micas in rocks affected by schistosity-parallel displacements

Document Type


Publication Date



Department of Geological and Mining Engineering and Sciences


Cross-micas are described in a rock for which relative displacements from sliding on schistosity planes have previously been demonstrated. Individual cross-micas in these rocks have incurred similar displacements along (001) surfaces. Shear strain on planes parallel to (001) in each cross-mica is determined and plotted on a map of the surface being investigated. The distribution illustrates that higher shear strains are found in cross-micas that are close to translation surfaces along which garnet porphyroblasts have been sliced into tabular sections. The study illustrated in this paper could be extended to other types of cross-micas and may prove to be a useful method for the investigation of strain history in foliated rocks.

Publication Title

Journal of Structural Geology