Surnadalssynklinalen. The Surnadal syncline, Central Norway.

The Surnadal syncline of the Trondhjem Region is situated in the western part of Central Norway. The geological map, Figs. 2 a and b, shows the western section of this syncline.

The present paper provides a brief description of the main stratigraphical, petrographical and tectonical features of the investigated area. The following groups are described: The Eo-Cambrian Tingvoll Group, the Cambrian- low Lower Ordovician Røros Group and the Lower Ordovician Bymark-Støren Group.

The Surnadal syncline present in the Stangvik-Hamnesfjord-Surnadalsfjord district corresponds to the Molde-Tingvoll syncline (Hernes 1955, 1956). The geological section, Fig. 3, shows that the Surnadal syncline forms part of a larger tectonical unit - an overturned fold with an essentially horizontal axial plane.