The entire massif consists mainly by moldanubic, i.e. series of rocks generated during sedimentation in precambric sea and wrinkled later into mountain chains and composed of crystalline slates and schicht gneiss (a metamorphic rock with foliations), mica schicht and quartzite. Rocks in the syntectonic migmatite of the Orlické mountains create Suchý vrch shortly beforeprecambric period.