The Grong-Olden culmination (GOC) represents an interference of two major basement folds: the E-W
trending Kolåsfjell antiform and the N-S trending Olden antiform. Basement-cover contacts along
the GOC vary in nature and age. Along the southem and western margin, basement and cover are
conformable, and the basement-cover contact is plastically folded. These folds can be traced over the
entire culmination. The northeastern basement-cover contacts are formed by a shear zone that occurs
below the parautochthonous cover. This shear zone abuts the internal structure of the GOC. It is
concluded that from W to E the basement-cover contacts become younger relative to basement structures.