The Fongen - Hyllingen layered intrusion, Trondheim region, Norway: an excursion guide

Abstract

The Fongen-Hyllingen complex, situated 60 km southeast of Trondheim, Norway, comprises the 160 km2 Fongen-Hyllingen layered mafic intrusion (FH1) and the slightly younger, minor (3 km2) mafic to ultramafic Treknattan intrusion. The FH1 was emplaced synorogenically in the Scandinavian Caledonides -435 Ma ago. Folding and subsequent uplift and erosion allow access to the floor, walls and roof of the magma chamber. The complex itself has been affected to some extent by deformation and metamorphism, but sufficient primary features remain to study magma chamber processes in detail.