Localised open fold sets with an interpreted post-Tertiary age are superimposed on the Hercynian deformation. These folds occur in Tertiary exposures about 50 km to the south-west of the Muruntau deposit. A further 70 to 100 km of right-lateral movement occurred along the Karatau fault during the late Mesozoic and early Tertiary (Alexeiev et al., 1997).