The Bygdin conglomerate, a quartzite conglomerate in the Valdres Sparagmite, was deformed by an overriding thrust-sheet of igneous rocks moving towards SE. The boulders of the conglomerate were drawn out in a NW -SE direction. Accompanying this deformation there is folding on NW -SE axes, both stretching direction and axes of folding pitching commonly 10-20° NW. The fabric patterns of quartz and sericite in the deformed boulders are girdles with a direction NE-SW. The folding and the production of the girdles are interpreted as produced simultaneously with the mass transport towards SE, caused by a triaxial deformation by which shearing stresses operated on planes striking NW-SE as well as on planes striking NE-SW.
Structural petrology of the Bygdin conglomerate.