Journal of

GEOsciences

  (Formerly Journal of the Czech Geological Society)

Original Paper

Přikryl, Karel Schulmann, Melka

Perpendicular fabrics in the Orlické hory orthogneisses (western part of the Orlice-Sněžník Dome, Bohemian Massif) due to high temperature E-W deformational event and late lower temperature N-S overprint

Journal of the Czech Geological Society, volume 41 (1996), issue 3-4, 156 - 166

A dominant structural pattern of the mostly granitic core of the Orlice-Sněžník Dome is N-S stretching associated with general top-to-the-north oriented shearing. Detailed microstructural study of deformed granitic rocks has shown a more complicated structural evolution. The early D_i ductile deformation is accompanied by partial anatexis. This E-W stretching is developed either in anatectic orthogneiss as a dominant feature or in deformed granites as a relict structure. Dominant N-S linear fabric of D_ii overprints D_i structures so that they are scarcely macroscopically visible at few places. Dominant D_ii northward non-coaxial shearing reactivates original S planes in older granites as well as deforms originally unstrained rocks. The complicated structural pattern of the Orlice-Sněžník Dome orthogneisses indicates two independent tectonometamorphic events from which the first one could be pre-Variscan. The second compressional event is undoubtedly Variscan in age.