Fundamental subdivisions of Precambrian granitoids in the Åmål mega-unit and the evolution of the south-western Baltic Shield, Sweden

Abstract

Abstract The “Amal-Kroppefjall granites” have hitherto been regarded as belonging to the “Gothian orogeny” of southern Scandinavia and have been considered equivalent to the Smaland-Varmland granites of south-eastern Sweden. In the Amal-Kroppefjall region there actually occur several groups of granitoid intrusives of widely different ages and lithotectonic characteristics. The good state of preservation of the rocks in this region is due to its synclinorial subsidence during and after a major event of regional metamorphism and migmatization affecting much of south-western Scandinavia. It is concluded that the concept of a single coherent development of the “Amal-Kroppefjall granites” and the previously suggested correlations and definitions of the “Gothian” in southern Scandinavia are untenable.