Deformation and metamorphism of Devonian rocks in the outer Solund area, western Norway: implications for models of Devonian deformation

Many modern accounts of the Devonian rocks of western Norway, which emphasi se the extensional processes by which the basins were formed, tend to ignor e or gloss over the deformation and metamorphism which these rocks have suf fered during contractional deformation. The present account describes exten sive ductile folding, penetrative cleavage formation and low-grade regional metamorphism developed in the Devonian strata of the outer Solund region. Although the deformation in this area is more intense than in other Devonia n basins, it belongs to the same movement plan. It will also be shown that the Devonian rocks of the Scandinavian Caledonides apparently share a commo n tectonothermal development. This regional contractional event, conceptual ly, may relate either to a Mid-Late Devonian arc-continent collision, or to a transpressional strain regime.