The geology and evolution of the southwestern part of the Kongsberg series

Early (?Svecofennian) Upper Arnphibolite grade metamorphism and granitisation of supracrustals and dioritic-gabbroic intrusives were followed by a much later period of cataclasis along the western margin of the Telemark block. Subsequent granitic activity welded the two complexes together, but later Greenschist 'friction breccia' movements were concentrated in the granitic rocks. Sveconorwegian metamorphism (at the end of the cataclasis) caused Mid-Amphibolite myloblastic and blastomylonitic recrystallisation. Subsequent retrogressions at 'Epidote Arnphibolite' and Upper Greenschist grade, were almost total in the western cataclastics, but negligible eastwards in less sheared rocks. The earliest, basic ('Vinor') intrusions were affected by very late cataclastic movements, but others were post-tectonic. Relationships with the Oslo Region and the Bamble and Telemark blocks are also considered.